PP1 høy ytelse RIAA vakuumrør flytende magnet forforsterker-modul Denne kretsen er basert på den berømte Marantz 7C vakuumrøret audiophile preamps phono-delen. Dette er ikke din gjennomsnittlige phono preamp krets. Omfattende utvikling og pålitelig produktstøtte går inn i hver jeg produserer. Det er ikke på tide du eide de beste enkle forbindelsene. Legg til 285VDC og 245VDC, 6.3V varmespenning, inngang og utganger og du er i virksomhet. Høytliggende keramiske rørstikkontakter forhindrer at rør fra et uhell rister løs fra stikkontaktene. RIAA utjevning og den suveren byggekvaliteten til denne enheten gjør at du kan nyte vinylsamlingen din på en måte du aldri har hørt før. Utrolige detaljer, ultralett respons og den klassiske lyden av vakuumrør. Hvem kan be om mer. Denne kretsen er tett basert på Marantz 7C phono kretsen. Selvfølgelig ville den fysiske størrelsen på komponenter som var tilgjengelige for Marantz på 50- og 60-tallet, ikke ha gitt dem mulighet til å bygge en slik kompakt enhet. Kretskortet måler kun 2quot X 6quot og kan monteres på det horisontale eller vertikale planet. Kobber som kreves er 2X 12AX7 og 1X 12AU7 (eller bruk 3X 12AX7 akkurat som den originale kretsen). Du kan kjøre varmeovner på DC eller AC. Du får selvfølgelig mindre frihet med DC. Faktisk vil den spesielle frontendeskjermplaten montert på loddesiden av kretskortet (ikke vist) kombinert med fullt jordplan på komponentsiden av brettet redusere EMI til en praktisk, ikke-eksisterende tilstand. MERK - Vakuumrør er ikke inkludert i denne kretsenheten og er kun vist som eksempler på disse bildene. Kretskortet er konstruert av dobbeltsidig 1oz folie varmluftnivå FR4 glass. Alle tilkoblinger er belagt begge sider for ekstraordinær komponentoppbevaring uansett varme - eller vibrasjonshensyn. Enkel impedansjustering oppnås ved å bevege selgeren shunts til ønsket impedansposisjon. Du har et valg av 22KOhm, 47KOhm og 100KOhm inngangsimpedansposisjoner for å matche preampen din til nesten hvilken som helst magnet (MM) - patron. Alle komponenter er spesielt utvalgt for stabilitet, stram toleranse og lav støy. Dette er en førsteklasses kvalitetskrets som er klar til å gi deg den ultimate opplevelsen i phono listening enjoyment i mange år framover. Inngangsimpedans er enkelt satt til 22KOhm, 47KOhm eller 100KOhm ved å flytte jumpers til ønsket innstilling. Vurder å plukke en av disse opp. Tilgjengeligheten er svært begrenset. Byggekvaliteten er fremragende, og tilkoblingen er enkel, spesielt hvis du har noen erfaring med vakuumrørkretser. Dette er en fullt montert enhet, og alt du trenger å legge til er strøm, rør, og inngangs - og utgangstilkoblinger. Gjør en perfekt følgesvenn til noen DIY rør linje amp stadium. Begynn å lytte til vinylen din og nyt den igjen. ELUSIVE RIAA RESPONSE CURVE Den ideelle RIAA-utjevningskurven må holdes så nært som mulig for å sikre en høy ytelse med flytende magnetforsterker. Mange fastprodusentprodusenter benytter kompliserte kretsdesign for å overholde RIAA-standarden. Designene spenner fra relativt enkle transistoriserte kretser til komplisert digital signalbehandling, men den gode gamle 7C-designen fra og med på 50-tallet holder det enkelt, men nøyaktig. Denne designen hadde det riktig i utgangspunktet, men ingeniører og audiophiler insisterer på å oppfinne hjulet og har gjort det siden 1950-tallet. Gjør det noe fornuftig Jeg er en tilhenger av kvoten Hvis den ikke brøt, ikke fikser det med tankegang. Diagrammet nedenfor representerer den ideelle RIAA (Recording Industry Association of America) phono utjevningskurven. Diagrammet som følger diagrammet, beskriver frekvenspoengene og forsterkningsegenskapene for den ideelle RIAA-responsen og faktiske avlesninger tatt fra en typisk PP1-forspenningsmodul utstyrt med tre 12AX7 vakuumrør målt på en Hewlett Packard 3582A FFT-spektrumanalysator. Legg merke til de små variasjonene i gevinst mellom den ideelle utjevningskurven og de faktiske avlesningene. Faktisk er de større forskjellene, eller feil hvis du ønsker, skyldes avvik mellom spenningsprøver tatt av spektrumanalysatoren. Inngangsspenningen til PP1 er tilfeldig hvit støy flatt over lydspekteret. Analysatoren er satt til å vise RMS-målinger med Hanning-filterrespons. Ideell RIAA utjevningskurve Dette er et eksempel på hvordan det hvite støyutgangssignalet ser ut. Skjermen ble tatt på en Tektronix 7D20 digitizer. PP1 ble designet med topp hylle test utstyr fra Tektronix og Hewlett Packard. Ingen detaljer ble tatt for gitt for at jeg kunne gi deg det høyeste pålitelighetsproduktet til en pris som sammenlignet med billig import. Jeg vet at du er fornøyd med konstruksjonen, ytelsen og den enkle installasjonen av PP1 phono input preamp-modulen. Det harde arbeidet ble gjort på forhånd, slik at du ikke ville måtte gjøre det. Bare sett på kretsen, koble til strømforsyningen, legg til rør, og bruk den tiden du har lagret for å nyte musikken. Hewlett Packard 3582A-skjermen viser målt frekvensrespons av en PP1 phono preamp-modul. Tilfeldig hvit støy påføres inngangen til forampen. Spekteranalysatorens skjerminnstillinger er 10dB per vertikal divisjon og 2,5kHz per horisontal deling. Frekvensbåndbredden som vises, er 0 Hz til 25 KHz. Total total amplitude differensial er like under 40dB med 0dB referansen ved 1KHz som indikert av markøren. Merk at denne skjermen ser litt annerledes ut enn den ideelle RIAA-kurven ovenfor. Det ideelle utjevningsdiagrammet er basert på en logaritmisk horisontal skala mens spektrumanalysatorvisningen er en lineær skala. Her er noen tilbakemeldinger fra tilfredse kjøpere, og jeg hekta alt opp i går og suksess. Målingene ved belastning (etter at tilførselen har gått en halv time): Varmepumpe er 6,32, 245 V trykk er 248 og 285 V trykk er 278. Forsterkeren med de installerte rørene var koblet til stereoanlegget på den tiden, og WOW. Fired oppe. Jeg spilte flere kvotalitetsopptaksspor LP'er jeg er veldig kjent med og styret ditt passerte syreprøven - stort, dypt lydfelt, og jeg hørte detaljer jeg har aldri hørt før. Og som det beste lydutstyret, da det brenner i utgangskvaliteten blir enda bedre. Tusen takk for hjelpen din og la meg legge til et killer phono-stadium for pennier i forhold til hva en komparativ pre-built versjon av denne kvaliteten ville kjøre. For flere måneder siden, kjørte Stereophile magazine en anmeldelse av et phono-stadium som som din quotwas er basert på Marantz 7Cquot og bruker de samme rørene. Som den versjonen jeg bygget den, kommer den også med en separat, frittstående strømforsyning. Alt til en pris på nesten 4000 USD. Sit COMING SOON - BRUKERGALLERI Ja, du vil kunne se på hvor alvorlige lydhobbyister verden rundt pakker inn PP1-preampene, samt får noen ideer og tips om konstruksjon. Hold deg nede Det er ikke mye valg i denne kategorien fordi svært få all-out oppstartsenheter har blitt laget av lydbransjen. De ble motet for 30 år siden av det innflytelsesrike (på tiden) magasinet The Absolute Sound. I deres kombinerte idealisme og teknisk uvitenhet, påpekt av både The Audio Critic og International Audio Review. De påvirket forforsterkerprodusentene til å bygge forforsterkere med høy forsterkning i stedet. Resultatene av denne kampanjen var enheter som var langt dårligere enn det som ble oppnådd med overlegne oppstart og lavkonjunktur. Kun den kombinasjonen kan beholde den ekte dynamikken, kroppen og lavnivådetaljene til det opprinnelige signalet. Ironisk nok, da en produsent i slutten av 1990-tallet endelig opprettholde en overlegne forsterker med forsterker, med en intern oppstart, tok det nesten ingen merke. Faktisk har Absolute Sound aldri gjennomgått det jeg plasserte denne enheten (Audion Premier Quattro) i klasse A i Forforsterker-delen. Viktig informasjon og fordeler Merk: Flyttbare patroner har generelt mer energi enn flytende magnetpatroner. Dette skyldes hovedsakelig at deres (stasjonære) magneter er kraftigere enn de som beveger seg. Problemet å overvinne er at deres energi er hovedsakelig i gjeldende. mens forforsterkere forstår og forsterker spenning. Denne feilpasningen kan overvinnes ved enten å forsterke sin eksisterende lille spenning eller transformere deres overskytende (og ellers ubrukelig) strøm inn i mer spenning før den når phono-trinnet i forforsterkeren. Phono-scenen forsterker deretter signalet og utligner det samtidig, ved hjelp av RIAA-utjevningskurven. Flyttende spole transformatorer - Dette er passive enheter (uten strømforsyning) som forvandler overskytende strøm fra den bevegelige spolen i spenning. som deretter kan forsterkes (og utjevnes) av (MM) phono-trinnet i forforsterkeren. Flytte spiralhodeforsterkere - Dette er aktive enheter, med strømforsyninger, som forsterker den lille spenningen fra bevegelige spiralpatroner slik at den tilnærmer den normale spenningen fra en bevegelig magnetpatron. Phono-scenen må fortsatt forsterkes og deretter utjevne signalet. Et annet navn for denne aktive typen enhet, som også er vanlig, er: Pre-forforsterker. Fordi det er passivt, har transformatoren noen teoretiske fordeler over hovforsterkeren, men kjøring er fortsatt kritisk for begge enhetene. Endelig er oppstartsenheter ikke phono-stadier. Phono Stages har sin egen separate seksjon. Viktig merknad - EMIASlagle Review bare nedenfor representerer mine siste tanker (2014). Alle innleggene og vurderingene som er sett under EMIASlagle ble skrevet i tidligere år og er nå utdaterte. EMIASlagle Silver MC Step Up Transformer EMIASlagle er en fremragende transformator, en av de tre beste ive noensinne har hørt. Imidlertid hadde jeg en uvanlig vanskelig tid, ved å sammenligne den med Bent Audio Silver. som har vært min personlige referanse siden 2006. Så jeg bestemte meg for å spørre to av mine medarbeidere for å hjelpe meg. Jeg måtte føle meg sikker på at vi fikk det riktig, og at vi ikke savnet noe, for bedre eller verre. Så, etter mange AB-sammenligninger (mest gjort av meg selv), er jeg glad for å rapportere at vi alle hørte de samme lydforskjellene, selv om våre reaksjoner på det vi hørte var noe annerledes. The EMIASlagle Vs The Bent Silver Den Bent Silver var merkbart overlegen i de områdene som alltid har vært sine sterke drakter. Den hadde en lavere lydgulv, større delikatesse og umiddelbarhet, gjengitt mer fine detaljer, var mer sammenhengende og hadde overlegen fokus. EMIA var også utmerket på alle disse områdene, men fortsatt nest beste i forhold til Bent. EMIA hadde imidlertid en lett merkbar fordel, men for mange audiophiler kan det være en svært viktig og kritisk faktor. EMIA hadde den beste basgjengivelsen vi noensinne har hørt, om noen MC-oppstart i kraft, frekvensområde, detalj og soliditet . Faktisk, siden jeg følte at det var enestående (spesielt for sølv), prøvde jeg alle utfordrende LP jeg kunne finne noen svakhet i EMIAs bassgjengivelse, men jeg mislyktes. Bare kvaliteten på Bents-basen kunne matche EMIA, men ingenting annet gjorde det. Videre var EMIAs bildestørrelse også enestående, litt større enn selv Bent, men på bekostning av noe fokus. Våre tre reaksjoner varierte alt når vi hørte disse soniske forskjellene. Min første samarbeidspartner (som har de mest konvensjonelle musikalske preferanser) ble litt revet mellom dem, først foretrukket en SUT, så den andre SUT, avhengig av musikken. Min andre assosierte foretrukket Bent-perioden. i alle tilfeller følte det bokstavelig talt, i sine egne ord, i en annen klasse. Min reaksjon er forskjellig, men absolutt nærmere den andre assosierte jeg, uten tvil, foretrekker Bent generelt. men jeg anerkjenner at EMIA kan være mer tilfredsstillende med visse opptak (spesielt ikke-klassisk). Videre gir jeg den andre assosianten mer vekt av to grunner først, hans smak i musikk er nærmere min (klassisk orientert, i motsetning til den første assosianten), og for det andre hørte han Bent på sitt beste, i motsetning til den første assosianten (se Another Bevis under), som bare hørte EMIA på sitt beste. Det er først relevant å merke seg at Bent Silver nå har vært lengre utgått (og er nesten umulig å finne brukt). Dette betyr at EMIASlagle bare kan være det beste SUT Jeg vet at det faktisk bygges og er tilgjengelig i dag. Den har bare en seriøs konkurrent som jeg vet om, Coincident Statement. som er ærlig liknende (til beste av mitt minne) til EMIA i ytelse (samlet og i detaljer), og til og med selger for samme pris (2500). Dessverre vil jeg ikke kunne gjøre en direkte sammenligning mellom de to. Jeg kan trygt si at en lydfil ikke kan gå galt med noen av disse to modellene, siden de begge er fremragende utøvere. Faktisk, som jeg sa tidligere i Sammendragsrapporten, er det mulig (hvis ikke sannsynlig) at mange lyttere kanskje foretrekker enten (eller begge) av disse to nåværende oppstrammingene til Bent, på grunn av den større populariteten til deres relative styrker . Men i vår erfaring møter ingen av dem Bent Silver i sine unike styrker, og derfor holder jeg det fortsatt i systemet mitt som min personlige (ultimate) referanse. Lydsystemet var ellers det samme under hvert forsøk. Kabelen som ble brukt fra EMIA var en 3-versjon av referansekabelen (også brukt fra tonearm), mens Bent har sin egen 9 (internt tilkoblet) kabel til Jadis JP-80 phono-scenen. EMIA hadde litt mer gevinst enn Bent, så jeg brukte volumpotter på linjestadiet, bare ett klikk, for å utjevne dem. Et annet bevis - min andre assosierte og jeg oppdaget at det var mye lettere å høre (mesteparten av) lydforskjellene mellom Bent og EMIA etter Graham tonearm-kabelen ble erstattet av Reference-kabelen. Før bryteren ble Bents styrker uforholdsmessig kompromittert av Graham kabler mangler, og derfor hadde jeg en uvanlig vanskelig tid å sammenligne dem først. Dette er også ytterligere bevis for en langvarig lydteori fra meg (og mange andre). Selv en svak lenke er nok til å maskere soniske forskjeller som ellers lettere observeres mellom to komponenter (og til og med programvare). Min første assosierte sammenlignet bare Bent og EMIA ved bruk av Graham-kabelen, som er hovedgrunnen til at jeg gir sin mening mindre vekt enn jeg normalt ville. EMIA var på sitt beste med Graham tonearm-kabelen. som gjorde at alle styrker kunne høres, mens de relative svakhetene ble minimert. Det er en spennende kombinasjon med det riktige musikalske materialet som er innspilt, stor skala, dynamisk og med kraftig bass. Imidlertid er det også viktig å merke seg at EMIAs største soniske dyd, dens bassgjengivelse, i sin tur var uforholdsmessig kompromittert av referansekabelen. Dermed viste ingen kabel hele lydsannheten. Dette viser videre den svake koblingsteorien, samtidig som den demonstrerer den kritiske betydningen av signalkabler i visse situasjoner. De viktigste vurderingene: Medieval Xmas MusicNonesuch, Pines of RomeMaazelMobile Fidelity, PlanetsPrevinEMI Intact Audio (Dave Slagle) SAMMENDRAGSMELDING MC TRANSFORMER Coincident Statement er en av de fineste MC-trinnene jeg noensinne har hørt. av hvilken som helst type eller for enhver pris. Men Coincident og den andre toppklasse A-referansen, Bent Audio Silver. begge har soniske fordeler i deres favør. Her er detaljene for alle de direkte sammenligningene mellom de to av dem (inkludert senest i 2012): Samtalen var litt overlegen i rekreasjon av kropp, dyp bas og bildestørrelse. Dette ble lettest hørt i cellobaritonområdet og lavere. I mellomtiden har Bent Silver sine egne fordeler i umiddelbarhet, delikatesse, gjennomsiktighet, renhet, fart, forståelighet og fokus. Bents-forbedringene er imidlertid like merkbare som Coincidents-forbedringene. Bunnlinjen: Jeg foretrekker fortsatt Bent Silver i mitt eget system på dette tidspunktet, fordi forbedringene bedre samsvarer med styrken til min (Jadis JP-80) phono scene og mine musikalske preferanser. Imidlertid har jeg fortsatt mistanke om at mange lyttere kan foretrekke Coincident over Bent, spesielt siden dets styrker er noe lettere hørt, og det må ikke glemmes at Bent (hvis det enda kan bli funnet i utgangspunktet) er veldig vanskelig å optimalisere, og kan være magert på mange systemer, uansett lasting. Sammenfallet kan til og med bli ytterligere forbedret ved lodding av andre motstandsverdier inne i enheten, noe som da vil redusere noen av de små soniske fordelene ved Bent Silver. Det er få odds og ender som kan vise seg å være viktige for noen lesere. Først av alt har Coincident rundt 2 db mer gevinst enn Bent (når alt annet er like). Dette var uventet, siden begge er spesifisert på nøyaktig 26 db. Når det ble spurt, Israel Blume. of Coincident, stod ved denne spesifikasjonen, så enten har Bent virkelig bare 24db gevinst (på sitt høyeste innstilling), eller Blume er feil, og Samfunnet har faktisk 28db gevinst, noe som er det samme som den tredje fremragende transformatoren Ive noensinne har hørt , den ekspressive teknologien (ET) SU-1. Deretter er det det kritiske lastingsproblemet. Bent har utvendige innlegg, som lett og bekvemt kan lastes med motstander for å nå noen verdi. Samfunnet har en bryter på bakpanelet, med 4 stillinger, mens ET har ingen brukervilkår for lasting (kort etter DIY, etter at chassiset er åpnet). Samfunnet kan også lastes inn i DIY-stil, men det innebærer også lodding. Bent, til tross for den enkle lastingen, er fortsatt vanskelig å optimalisere med mange patroner og systemer, og dette er den største svakheten. Når det gjelder utseende, har Coincident samme form og utseende som Line Stage fra samme selskap. Det er også ganske betydelig for en transformator, som veier rundt 25 kg. og den har utmerket skjerming. Som anbefalt, brøt jeg inn Coincident-transformatoren med 300 timer med forskjellige (line-level) CD-signaler. Til slutt, mens vi ikke kunne prøve ut et stort antall kabler, kan jeg si at Statementet hørtes best med Coincidents own Extreme Interconnect-kabler som går til (Jadis) phono-scenen. Så, hvor står vi nå i Class A Step-Up Universe. Jeg vet om tre store MC-transformatorer: The Coincident, Bent Silver og ET. De to sistnevnte er nå langt utgått. og ekstremt vanskelig å finne brukt. The Bent, hvis noen gang funnet brukt, kan være en ekte handel. Hva om du allerede eier Bent, jeg tror ikke det er verdt å gå til Coincident, med mindre du bare må ha ekstra gevinst, eller du har problemer med leanness, til tross for å prøve forskjellige belastninger. Den virkelige shake-up her er med ET, som vanligvis går for store penger hvis funnet funnet. noe som betyr noe i 4.0005.000-serien. I motsetning til dette selger den nye Coincident Statement for 2.500. Kort sagt, jeg ser ingen grunn til å søke etter en brukt ET lenger, enn si betale seriøse penger for det. Samfunnet har merkbart (men subtilt) bedre ytelse, mer allsidighet og det koster nesten halvparten av prisen (og det ser enda mer elegant ut). Tilfeldigvis bygde også en prototype sølvtransformator, men det var sonisk dårligere enn kobberversjonen (ifølge Coincident ownerdesigner Israel Blume). Fra et historisk perspektiv. Ser tilbake over de siste 25 årene. som var da den (da revolusjonerende) ET først kom fram på scenen, tror jeg nå at vi er nær slutten av linjen til MC-transformatorutvikling. ET var det virkelig store hoppet, Bent Silver en fin raffinement over ET (men bare med riktig system), mens Coincident er en annen subtil forbedring over ET, men med større systemfleksibilitet. Trenden er nå åpenbar. Hvis, og når det er flere forbedringer, forventer jeg at alle skal være like subtile. Hvis dette ikke var tilfelle, ville det allerede ha vært mer alvorlige fremskritt i løpet av de siste to tiårene. Det faktum at disse topp tre transformatorene alle er svært like i ytelse, kan bare bety at de er nær perfekt, noe som er definert av meg, ikke i bokstavelig forstand av det (farlige og overbrukte) ord, men som det er mulig med dagens teknologi. Praktisk sett betyr dette at du kan kjøpe noen av dem med tillit, og aldri trenger å bekymre deg for forældelse. Imidlertid er de virkelig gode nyhetene at Coincident Statement er tilgjengelig nå. Til slutt, hva med Coincidents salgspris og verdi for pengene. Samfunnet er litt dyrt, men det er langt mindre kostbart enn noen av dagens konkurranse (spesielt modeller fra Japan og Europa). Faktisk er det viktig å huske at den (nå legendariske) ET opprinnelig solgt for 2500 (20 år siden). og det solgte til slutt for 3.500 (10 år siden). Følgelig, ved en sammenligning eller måling, Samfunnserklæringen, ved 2500. i 2012, kan bare beskrives som en eksepsjonell verdi for pengene. Samfunnet har også et phono-stadium som inkluderer to interne MC-transformatorer. Så, hva er historien der jeg ba Israel Blume om å kommentere dette. Her er hva han sendte meg (min dristige): MC-erklæringen kan kobles til 20 db eller 26 db gevinst. Modellen din er 26 db, ikke 28 eller en annen figur. Integrert oppstart i Statement Phono er identisk med den separate Statement Step-up på alle måter, bortsett fra at den er koblet til 20 db og ikke kan endres. Pris på erklæring MC Step-Up (Direkte salg kun) - 2.499 US Coincident informerte meg om at deres transformator har den laveste oppmerkningen av noen komponent de noen gang har solgt, og derfor blir den bare solgt direkte. Faktisk, med standard bransjemarkeringer, ville Coincident-transformatoren være detaljhandel for rundt 5000. Hvordan alt dette påvirker valget av et phono-stadium. En forsiktig leser kan legge merke til at forskjellene mellom disse to SUT-ene er svært lik de forskjellene Ive tidligere beskrevet mellom Coincident Phono Stage og Jadis JP-80 (svært modifisert. Og når du bruker Bent Silver). Dette betyr at minst noen av disse forskjellene var fra SUT og ikke de respektive MM-stadiene. Konklusjonen er da uunngåelig de to MM-stadiene er enda mer liknende enn jeg først trodde og beskrev, selv om de fortsatt ikke er like. Kort sagt, hvis du bruker Coincident MC SUT med (svært modifisert) Jadis JP-80 (omgå sitt eget dårlige MC-stadium), er den generelle ytelsen ganske lik den Coincident Statement Phono Stage. Forskjellene mellom de to MM-stadiene, mens de eksisterer, er relativt små i de fleste (men ikke alle) forekomster. Følgelig plasserer dette jadiene i en svært unik posisjon, og ber om spørsmålet Er jadiene til og med verdt å kjøpe først. Tenk på dette perspektivet. Jadis, hvis kjøpt brukt. og hvis det blir bedre med de mest økonomiske endringene (som fortsatt ikke vil utgjøre ytelsen til min referansemodell), vil det koste over 10 000. En førsteklasses SUT er fortsatt nødvendig, så vi må legge til en annen 3000 eller så (når også kablene er inkludert). Nå var det opptil 13.000, og i beste fall vil det fortsatt være bare konkurransedyktig (og ikke overlegen) til Coincident Statement, som koster 6.000. og er helt ny. Videre, mens Coincident vil lyde enda bedre med det tilsvarende (5.500) linjestadiet, krever det ikke det, mens Jadis krever det. bringer den totale kostnaden til rundt 19.000 (når den også inkluderer et annet par kabler). Så, mitt perspektiv og råd om klasse A referansefonetrinn har nå blitt endret. På denne tiden (0412) ser jeg ingen grunn til å kjøpe Jadis JP-80 (MC). Det eneste mulige unntaket ville være hvis du allerede har en Bent Silver SUT, eller vet sikkert. du kan få en og er også forberedt på å utføre alle mine JP-80 modifikasjoner. Selv om du allerede eier en JP-80 (MC), vil jeg selge den med mindre du har tilgang til en Bent Silver, og er også forberedt på å kopiere alle mine modifikasjoner. Hvis dette er gjort, vil du ha et overlegent phono-stadium, men vil ha betalt en stor kostnad for den lille overlegenheten. Hvis ikke, vil noen soniske fordeler over Coincident Phono Stage, hvis de eksisterer i utgangspunktet, være mindre i beste fall, og da bare etter å ha gått gjennom store problemer og kostnader. Verre, det må ikke glemmes at selv da vil det fortsatt være merkbare soniske fordeler. The Bottom Line-En investering i Jadis, ny eller brukt. er rett og slett uberettiget under nesten alle praktiske forhold. Til slutt: Hva med meg har jeg allerede Bent Silver, og jeg har allerede gjort alle de kjente modifikasjonene på JP-80, noe som gjør meg så sjeldent unntak. Jeg foretrekker åpenbart sluttresultatene, så jeg beholder det jeg har. Kanskje jeg var heldig, eller kanskje jeg var tålmodig, men jeg har det jeg vil ha for nå. Som jeg beskrev i detalj i del to av 201112 phono stage essayreview. En viktig oppdatering fra november 2012. Ive hadde en Coincident MC Transformer inn og ut av systemet mitt i mer enn to år nå, men inntil nylig leste jeg bare standard 26 dB-versjonen (jeg regner ikke med versjonen som brukes i Coincidents Phono Stage). Nå har jeg endelig hørt 20 dB-versjonen (med Jadis JP-80). Det er nøyaktig samme transformator, bortsett fra noen få enkle interne ledningsendringer. Disse endringene kan gjøres ved Coincident på kjøpstidspunktet, eller senere av enhver som er praktisk med loddejern (ca. 30 minutter), og de kan reverseres om ønskelig. Så, hvordan sammenligner de med hverandre (Referansesystemet var akkurat det samme, inkludert kablene.) Enkelt svar: 20 dB er overlegen, på samme måte som en .25mV-versjon av en MC-patron vil bli bedre enn den .50mV-versjon av samme patron (men ikke i samme grad). Den 20 er litt raskere og mer klar og presis (lettere på føttene), og uten ulemper som jeg kunne oppdage. Den 26 hørtes ut som en kassett med VTF satt litt for høy. De to versjonene er åpenbart mye mer liknende forskjellige, men de små forskjellene som finnes eksisterer alle til fordel for 20. Så hva anbefaler jeg til de som er interessert i å kjøpe denne komponenten. Hver som har anstendig vinning i phono-scenen, pluss en linje i systemet, skal få 20. Hvis du ikke er sikker, vil jeg fortsatt få 20 hvis du (eller en venn) er kompetent med loddejern, siden det lett kan konverteres tilbake til en 26 hvis nødvendig. Hvis systemet krever hver dB av gevinst, kan det få, enn du ikke har annet valg enn å få 26. Prisen er den samme for begge, så det er ikke en faktor. Endelig, hva med noen som allerede har (26) Sammenfall i deres system Hvis du har mer gevinst enn du trenger, ville jeg få den til å bli endret til en (20), ASAP, en eller annen måte. Del 2 - Sammenligning av 20 dB Sammenfallende med Bent Sølv SUT Som jeg tidligere har gjort (etter å ha kommet et generelt inntrykk av Statement med et bredt spekter av musikk), gikk jeg frem og tilbake flere ganger med noe spesifikt (og godt kjent) program materiale. Jeg unngikk nøye med å lese mine tidligere vurderinger, på grunn av min bekymring for potensiell forspenning (og lat tenkning). Overraskende, jeg måtte holde Bent ved sin (nåværende) 26 dB innstilling for å matche samme volum (eller gevinst) nivåer av Coincident ved sin 20 dB innstilling. Jeg kan ikke forklare årsaken til denne åpenbare uoverensstemmelsen i spesifisert gevinst, som jeg har nevnt før (selv om det kan være relatert til den brukte phono-patronen). Til slutt brukte jeg den siste Coincident (topplinjen) interconnect kabel fra transformatoren til (Jadis) phono scenen, som ble foreslått (og levert) til meg av produsenten. Resultatene etter alt dette. Jeg skjønte til slutt at ikke mye hadde forandret seg. Jeg antar at forskjellene mellom de to Coincident-innstillingene (26 og 20), mens det var merkbar, ikke bare var så stor i det store bildet. Kort sagt, jeg foretrekker fortsatt Bent Silver, i mitt eget system. av samme grunner som jeg har gitt før (se Referanse MC Step-Up File for detaljer). Og, som tidligere, er det fortsatt små plusser og minuser for begge. Bruke My HierarchyLevels of Audible Improvements. Jeg har tidligere beskrevet Bent SilverCoincident som en forskjell på nivå 3, mens jeg føler at forskjellen 2026 er nærmere et nivå 2. Videre er det viktig å huske på at disse forskjellige nivåene ikke er absolutt eller nøyaktige. Det er nyanser på hvert nivå (2.1, 2.2, 3.1, 3.2 etc). I virkeligheten kan det ta flere nivå 2 endringer som bare er lik ett nivå 3-endring. Så til slutt forblir alt det samme, med unntak av det jeg allerede har beskrevet og underrettet i første del av denne oppdateringen (ovenfor). The Bottom Line-The 20 Coincident er en merkbar forbedring i løpet av de 26, og skal brukes hvis det er praktisk, men det lukker ikke det (enda mer) merkbare ytelsesgapet mellom det og Bent Silver, i hvert fall i systemet mitt. Selv om det er mulig at Coincident kan bli enda bedre forbedret med en intern motstandsimpedansendring (noe som betyr at jeg fortsatt ikke kan havent hørt det på sitt aller beste), ville jeg ikke gjøre den innsatsen på dette tidspunktet. Til slutt, for å gjenta igjen, The Big Picture når det kommer til de fineste MC-transformatorene jeg noen gang har opplevd: Det er bare tre flotte oppstartstransformatorer som jeg vet, med sikkerhet. å eksistere Den ultra sjeldne Bent Silver og Expressive Technology SU-1 (begge langt utgått), og den fortsatt tilgjengelige Coincident Statement. Den ekspressive er (nå) overpriset når den er kjøpt brukt, og den har ingen impedansbryter, selv om den har betydelig gevinst (28 db). Bent har det høyeste potensialet i min erfaring, og det har også den enkleste og beste impedansbyttingen, men den har minst gevinst og mangler muligheten til å legge til kropp til en magert (ish) patron (eller system som allerede har diskvalifisert det i mer enn en gang forekommer jeg personlig), så det er en reell risiko for uforenlighet. Samfunnet har også mye gevinst, anstendig impedansinnstillinger (selv om presis vil kreve intern lodding) og den er kompatibel med alle phono-patroner (eller - systemer) jeg kan forestille meg. Flott - Ikke engang en alvorlig feil Ive noensinne har hørt. BENT AUDIO TX-103 SILVER TRANSFORMER Bent Sølv er fortsatt den fineste bevegelsespolen oppstigningen jeg noensinne har hørt. Mine medarbeidere stemmer overens med denne oppfatningen. Vårt største forbehold er at det må lastes inn riktig (se detaljene i den dedikerte filen. Lenke nedenfor). Bent Silvers fremragende ytelse inspirerte meg til å skrive et grundig perspektiv og historie om Step-ups, som til tross for deres kritiske betydning i et phono-system, nok har vært den mest ignorerte og forsømte komponentkategorien i både forskning og utvikling. Denne lydapati er den primære grunnen til det ynkelige valget av modeller som er tilgjengelige for seriøse lydfiler. Bent Audio Silver MC Transformator Dedikert fil EXPRESSIVE TECHNOLOGIES SU-1 TRANSFORMER Den uttrykksfulle var den eneste klasse A-opprullingen noen av oss noen gang hadde opplevd. No other step-up that I am aware of, except the Bent Audio Silver above (along with the Bent Copper and ZYX below), even comes close to it. It is virtually flawless in sound quality. This company is now out of the audio business . another audio tragedy. This transformer performs at its best with low impedance moving coils. It doesnt work well with all cables, because of the potential groundhum problems. The input impedance of the preamplifier should be 47K. The ET will improve the performance of all preamplifiers, with the single exception of the Audion Quattro . and maybe some custom models that have recently become available. It was very expensive at 3,500 U. S. . Very difficult to find used. This may be that extremely rare final purchase. (I would avoid using their own phono cables. While they are very good and well made, there are others that are even better.) FURTHER - Expressive Technology also had an all-out preamplifier, with a phono stage. They worked on it for 7 years. It cost 15,000 . and only a few were made. This is the preamplifier that Myles Astor . of the (now former) print magazine Ultimate Audio . actually refused to listen to with his own analog front end. See Reviewing the Reviewers . I dont know anyone who has actually heard it. ZYX MC CPP-1 PRE-PREAMP This is, most likely, the finest head-amp Ive ever heard. I state this because it is competitive with the finest transformers Ive had, while all the many other (external) head-amps Ive heard are simply not in that league. Disclosure - The ZYX head-amp is a solid-state device It is highly unusual for a successful cartridge manufacturer to also design and build an audio component that is so different in fundamental nature (non-mechanical in this instance), with such excellent performance. The relevant details. The ZYX Compared to the Bent Silver The ZYX basically equals the Bent Silver TX-103 transformer in immediacy, neutrality, frequency extension and the size of the soundstage. The ZYX has excellent channel separation, and the macro dynamics are absolutely breathtaking. In direct comparison, the Bent Silver is superior in two areas its ultra-low sound-floor and its freedom from electronic haze. These areas are considered subtle by many audiophiles, though not me, and can be especially noticeable on certain acoustical music. Please dont misunderstand me, the ZYXs background noise (hiss) is very soft, basically non-existant, and lower than any head-amp Ive ever heard. It just loses a bit of individuality, harmonic completion, sense of space and micro dynamic tension compared to the Bent Silver. Its not alone, so does every other step-up Ive ever heard. For the sake of perspective the ZYXs weaknesses, only compared to the Bent Silver, are still actual strengths compared to almost every other step-up Ive heard. Thats how good it is. In fact, there were many times I was not even able to distinguish between the two of them, because their basic sonic character is so similar . ( I wrote previously that I believed that even a perfect step-up wouldnt be that much better than the Bent Silver. This is because I felt that the Bent Silver is already pretty close to perfect itself. The closer components come to practical perfection, the more similar they must sound, no matter how differently they are designed and built. This is because they will have fewer imperfections to distinguish themselves from each other. All happy families resemble one another, but each unhappy family is unhappy in its own way.-Leo Tolstoy, Anna Karenina) The ZYX also has some practical advantages. Other Factors and Compatability While both the ZYX and the Bent Silver are rated at 26dB of gain, the Bent Silver loses some of its gain as soon as it is loaded-down, which is a requirement. The ZYX is already loaded-down as is, so it has more real gain in practice. For many systems, this may prove irrelevant, but in my own system, it is the difference between some records coming alive, or not. There is another advantage to the ZYX it is virtually cable proof, since it is an active device. While signal cables, both to and from the ZYX, are still obviously important, theres never going to be a true mismatch. Sadly, this is still possible with the Bent Silver, because it is passive by nature. Ive already directly experienced this potential problem. This reality can be critical for cable freaks andor experimenters. In short, the ZYXs high level of performance can be experienced in every system, while the Bent Silver, though it has even greater potential . will only reach that potential with time, effort, patience and maybe some further expense. Some Practical Information The ZYXs power supply consists of high-quality ( 9 NiCd ) batteries, which are re-charged in a few hours (overnight is easiest). It broke-in very quickly, only after around 10 hours or so of play. It doesnt sound good for the first few minutes of each session (its veiled, dry and ill-defined), but it warms up fast, and after 20 minutes (1 LP side), its already at its best. It can also be played while the batteries are being re-charged, but Im not sure about the sonic compromises, if any, while doing so. Despite the ZYXs relatively small size, and its lack of a large power supply reserve, I can assure you that its large dynamic swings, plus its middeep bass weight and impact, are as good as Ive ever heard. These qualities, plus its outstanding neutrality, immediacy and spooky silence, are what most impressed me about this unit. All of this was unexpected. The standard model of the ZYX pre-preamp has 20db of gain, with a slightly simpler circuit. Its very possible, if not probable, that it will sound even purer. Conclusion and Advice This is the step-up to get if you want superb sonics, complete background silence, with no fussing around and total cable compatibility. If theres a better head-amp around, I havent heard it, or even of it, yet. Its selling price is 1,650 . direct on Audigon . which is 375 more than the Bent Silver. This may be an issue for some. However, for those audiophiles who dont like any MC transformer, for whatever reason(s), the ZYX is a no-brainer choice, if its affordable. The Bent Silver still has greater potential, which is why it is in Class A . but I cant absolutely promise you that this potential will be realized in every system. For the most serious phono fanatics, meaning those audiophiles who are prepared to make every effort to optimize it, the Bent Silver continues to be my highest Reference and, it shoudnt be forgotten, it can never break down. Just dont forget the caveats Ive posted. It must be emphasized that I have not yet heard the Bent Silver or the ZYX CPP-1 at its best: The Bent Silver can still be loaded-down some more, and the ZYXs 20dB gain model has still to be properly auditioned. Both require either a more sensitive system, andor a cartridge with higher output. This will all happen in the next few months. The first ZYX UNIverse I will audition has a .48mV output (while the Airy 3 Im now using is .24mV ). Im also receiving more sensitive amplifiers and speakers from Coincident Speaker Technology . The more I think about this, 2006 is shaping up to be a truly major year for audio developments and its evolution. AUDIO RESEARCH MCP-33 The ARC was a pre-preamplifier that used 6DJ8 tubes as amplifying devices. It is one of the two best of its type ever made and is very well built. It is an excellent performer, but far behind the Expressive above, since it just makes this class. It can be improved with modifications. The biggest problems with the MCP-33 is that the high quality, low-noise tubes (6DJ8s) it uses are not only difficult to find, but they also turn noisy quite quickly. More Recent Information (305)- I received a letter from a reader who feels he may have solved the inherent problem of this component tube microphonics . Here it is, with slight editing After experimenting with various types of tube dampers and cones, I found that the spring suspensions made by Loyalty Sound of Alberta, Canada . could be the most effective cure for the noise problem associated with the MCP33. After supporting the MCP33 on a set of the Loyalty spring suspension, I found that there was no need to put tube dampers onto the 6DJ8 tubes. These spring suspensions could also be used to good effect for supporting CD players. I have heard significant improvements in sound stage and even tonal balance after a friend of mine put a set of these suspensions to support his Marantz CD7 . which build quality is already rather exemplary. It should be noted that however the spring suspensions must be carefully placed so that all three individual suspension is subject to a similar loading (which could be verified using a spirit level). Loyalty Sound offers different spring ratings (140 lb, 70 lb and 40 lb) for the suspensions. The suspensions I used for the MCP33 are of 40 lb rating. The spring suspensions, just slightly cheaper than the Goldmund cones . are quite expensive however. Personal Notes - This letter almost seemed like an advertisement for Loyalty Sound, but this reader is most likely unaffiliated with them, and he could be right, so Im requesting feedback about these springs from any reader who has first hand experience with them. Also, despite this readers judgement, I still feel that Herbies Tube Dampers are a requirement for the 6DJ8s used in this unit. The Classe was the finest solid-state head amplifier ever made (until the ZYX CPP-1 above). It was beautifully built, it weighed 35 lbs. . and it even had a separate, heavy-duty power supply. The majority of phono stages and step-ups of today are literally like toys compared to it. It had some (potential noise) problems with set-up when it came out because of the cables of its day, but that shouldnt be a problem now. The sonics can be described as very clean, detailed and dynamic. It still had some transistor problems (some dryness, darkness and hardness), but they were more subtle than any other solid-state model. TAS . in its review (Issue 34), also mentioned some soundstage anomalies. I didnt find them to be a serious problem. Its a shame that no one today makes a modern, improved equivalent of this component. This model will be hard to find, but its well worth the search. It was designed by the original (and now former) owner of Classe Audio, Dave Reich . who wasis both talented and passionate about audio. BENT AUDIO (STEVENS BILLINGTON) TX-103 COPPER TRANSFORMER I first heard this transformer in my friends system, where we compared it to the EAR MC-3 and the MC stage of his Audion Quattro . We both preferred it to the EAR, but we also felt the Quattro was still slightly better, overall. The TX-103 did have an advantage in the high frequencies when the music was loud and complex. It retained its integrity, while both the Quattro and EAR had problems. Ive now lived with the TX-103 in my own system for more than six months. When first compared to the EAR, it was slighty, though still noticeably, superior in transparency, immediacy, preserving inner details, definition and it had a lower sound-floor. They were basically equal in neutrality and in the frequency extremes. Since then, I have broken in the TX-103 using the helpful instructions from Thorsten Loesch . The improvement was quite noticeable, which means this transformer is now competitive with the Audion Quattro and the (Class A) Expressive Technology . (One of my associates will try to arrange a shoot-out with the Expressive and both the silver and copper TX-103.) The TX-103 has one important practical advantage that converts into a sonic plus its output consists of a short (7) wire with a RCA male termination, which allows a direct connection into the phono stage without the need of an extra cable. My TX-103 is a DIY copper version, but recently this company came out with finished models. According to their website, the copper version is 745 and the silver is 1,075 . I expect to audition a finished model, including the silver version, in the next month or so. See Bent Audio . the North America distributor, in the Links File for more information concerning this component. Break-In Instructions from Thorsten Loesch This worked very well for me, so I recommend it highly. This is what Loesch wrote, with a little editing: (The TX-103). will require a substantial period of forced burn in to give its best, simply because the magnetic core is huge and will not see much magnetisation with normal MC signals. Please consider connecting a CD-Player to the secondary (Output) of the TX-103 and then terminate the input with a low resistance resistor (quality uncritical), Id say 27 Ohm when connected for 14db gain, 6.8 Ohm when connected for 20db gain and 2.2 Ohm when connected for 26db gain. Leave with a highly dynamic, wide bandwidth signal CD to play for a week or two. I would use music, but Id expect pink noise to work well too. Personal Note - While on a weeks trip, I connected the signal (a tuner on a 24 hour grunge station) to the primary (Input) instead, and had great results. The rest of the circuit followed Loeschs instructions. MITCHELL COTTERVERION TRANSFORMERS These models were the finest moving-coil transformers ever made at one time, and the best I heard, overall, before the Expressive Technology came into existence. They had excellent sound natural, detailed and dynamic, though with both of the frequency extremes rolled off a little. It came stock with its own ( 4 ) output cables already attached, which was a strong advantage, but now it is a decided disadvantage. The cables excessive length and (now) mediocre quality both compromise the Cotters inherent performance. A competent technician must be found to remove and replace them with good quality RCA females, which would then allow the use of any superior phono cable. There are different models of this transformer that have different input impedances. The model with the lowest input impedance ( 2L ) is usually the most desirable version with current cartridges. The Verion was the exact same transformer as the Cotter, before the name changed due to legal reasons. However, unlike the Cotter, no version of the Verion was ever offered with the lowest ( L ) input impedance, as far as I know. FURTHER: The original Bryston transformer (black) was the exact same model as the Cotter, with just a different name and color. It was even built by Cotter. However, the current Bryston transformer, with the model name TF-1 . is a different design. Chris Russell . the CEO of Bryston, claims this model has a wider bandwidth and 40 of the measured distortion of the CotterVerion unit. I am sad to admit that I havent heard this unit, despite the fact that it is made in Canada. The RWR is a MC transformer that is very similar in sound quality, size and shape to the Cotter. The Cotter is only very slightly better. This model also has the important advantage of user switchable input impedances, which the Cotter lacks. This could be an important feature for those audiophiles who change their cartridges on a regular basis. It is very rare and was built in Canada. This is another transformer that is very similar in quality to the RWR above. Its also very rare and difficult to find. Further - A reader has informed me that he compared this model to a Verion (Cotter). He felt that the Verion sounded thin and harsh by comparison. He also commented that the Audio Interface lost nothing at the frequency extremes and had plenty of body. In another comparison, this same reader felt that a different version of the Verion was much better (a dramatic improvement), but it was still not the equal of the Audio Interface. Even if both of the Verions had an impedance mismatch, the fact that the Audio Interface was equal or better to them is a very strong endorsement for this model. KLYNE SK-2 PRE-PREAMP The Klyne is a very good and versatile pre-preamp, and its solid-state It is neutral and it retains the frequency extremes. This was the finest transistor head-amp before the Classe NIL came out, and it is very possible that it is still more neutral than the NIL. It also has switches for both input impedance and a variable capacitor filter to tame cartridges with high-frequency peaks, which were common 20 years ago. As for its performance, its somewhat dry and a touch noisy in comparison to the others. Their earlier model, the SK-1 was too noisy for very low-output pickups (below .4mV). This exact same headamp is also incorporated inside some of the Klyne preamplifiers. EAR MC-3 TRANSFORMER Ive lived with this transformer and I am impressed with it. I used it with a Shelter 901 within a system in which the entire front-end was new to me. Meanwhile, one of my associates also has some experience with it. The MC-3 has 3 inputs, each with different gain and input impedance, and one output. The sound varies with each choice of input. I had no problem with hum andor noise with it at any time. In fact, it is dead quiet, at least in my system. At its best, using the lowest impedance and gain with the Shelter, it is neutral and has excellent midrange naturalness, detail and dynamic force. The bass is also special, especially for a transformer, going deep and with detail and impact. The high frequencies are also good, being smooth and clean, but there is a sense of a rounding of the tiny details which individualize music. This may be caused by either a roll-off or a subtraction of low-level harmonics (and other musical information) or both. One other problem is that this model doesnt have the dynamic jump or shock of the Expressive Technology transformer, though it is competitive in this area with other step-ups. The Expressive should be better, costing more than 3 times the EARs price. The timing or phase of the EAR is good, but it is not quite as precise as the Expressive, so the music isnt quite as intelligible, and the soundstage isnt quite as large or as focused. This is the best value, in every way, for a step-up being made today that I know of. It may even be preferable to the other Class C models. Further - I have since heard this transformer on an associates system and I have also logged more hours on my system. I now feel that I can faithfully describe its performance. It is very neutral, and the frequency extremes are excellent, both are extended, especially in the bass. The dynamic qualities are also excellent. There are problems though. There is a noticeable drying of the sound meaning a reduction of low-level detail. You hear less definition, natural texture, air and harmonics developing and decaying. There is also a slight reduction of image size and focus musicians are a little diffuse sounding. It is still the finest MC transformer Ive heard for the money, but it wont join the Class B models as I had originally hoped. ( 603 ) CONRAD JOHNSON PRE-PREAMPLIFIERS (HV-1HV-1AHV-2PREMIER 6) I sold this line in the earlymiddle 1980s, and even owned one of these models personally for a time. They were all excellent, with full bodied sound that this company is famous for, and also less residual hiss than most typical tube headamps. The later models were a little more transparent, faster and cleaner than the original HV-1. Unfortunately, none of them were quite as immediate, clean, neutral or dynamic as either the ARC MCP-33 in Class B or the Counterpoint SA-2 below. They all used tiny 6CW4 Nuvistors instead of traditional 8-pin tubes, and I remember the circuit boards being suspended by rubber bands for improved isolation. I dont know whether or not these Nuvistors can still be replaced today. Win Research - This transformer may qualify for Class B or even Class A ranking. Stay tuned and hope for the best, because it is far less expensive than the Expressive. Counterpoint SA-2- This was a serious tube head amplifier. At its best, it was one of the two finest ever made, along with the ARC MCP-33 above. Unfortunately, it had problems with reliability, hum and excessive tube noise. The (6DJ8) amplifying tubes had a tendency to become noisy in a very short period of time. I had experience with two of the early models, and I was never able to keep them working, at an optimum level, for more than a week or so at a time. The later models were supposed to be improved, especially in the area of reliability, but I am not able to verify this claim at this time. I would avoid this model unless there is an extensive audition or a money-back guarantee. EAR - The early ( 1980s ) EAR transformer was very large and heavy for its time, and it had extraordinary gain and dynamic qualities along with a large sound and deep bass, but it also had problems with noise, hum and even had some frequency irregularities. In the right (though unusual) circumstances, it could be superb, but this is another try it before you buy it component. Koetsu - I was a Koetsu dealer for more than 10 years, and I had extensive experience with virtually all their cartridges and their moving coil transformer. Their transformer was expensive for its day, but then nothing from Koetsu was ever a bargain. It was enthusiastically hyped by the Koetsu distributor before it was released. The performance was mainly typical of the moving coil transformers of its day. It had an excellent midrange, definitely better than average, with good body and excellent retrieval of low-level information. The problem was the frequency extremes, which were noticeably rolled-off, especially in the bass. There was poor mid-bass impact as well. It was a big disappointment for me at the time. In the final analysis, this was a good but overpriced and over-hyped component, that never lived up to its very high expectations. The fact that it is mainly forgotten today is its testament. Quicksilver - This was a small and modestly priced transformer. It was clean, smooth, quiet and detailed. It was especially impressive in the high frequencies, with extraordinary extension for a transformer. Unfortunately, the bass was very noticeably rolled off and it was also dynamically compressed. Further, it was not quite as rich or as full-bodied sounding as the much more expensive Koetsu. It was still a good value, considering everything. Marcof PPA-1- This was a unique battery powered unit that was popular in the early 1980s. It was very inexpensive and had OK sound considering the cost. Its main sonic problems were a relentless background hiss, dynamic compression and a very noticeable dryness. This model is only for beginners or those on a really tight budget. Shelter - I havent heard this SUT model myself, but one of my associates had it in his system for a while. He said it was decent, but not outstanding, even for the money. Bobs Devices CineMag Step-Up Transformer I listened to this model for a few evenings, and having now returned to my current (Class A) reference, I am satisfied that I generally know what its doing, and not doing. Since this SUT costs far less than any of the models I have lived with, and reviewed, over the last 20 years, I was hoping that lightning would strike, but that was sadly not the case. Im sorry to report that its performance doesnt approach any of my top References. The details (as far as I can provide)- It lacks the immediacy, transparency, (inner an outer) detail, purity, speed and low sound-floor of the top reference models. It also has an easily noticeable character, which I would describe as warm, full bodied and forgiving. Some would call it musical for that reason, and I realize that some listeners are specifically looking for this, but it could also be justifiably described as predictable, which is not as flattering (or ever desirable for me). I also realize its unfair to compare the Cinemag, at 395 . with units costing 5 to 10 times more, but I dont have access to similar priced models at this time (in contrast to when I owned an audio store). To be frank, I also dont have the time, or the required interest, to audition anything less than all-out SUTs any more. So, in the end, I dont know how the CineMag compares to its true competitors. I can say that it is not irritating, as were many step-ups Ive heard in the past (mainly transistor head amps). The sound was always pleasant, whatever record I played (like early Magnepans ). Depending on your perspective, this could be either a positive or negative attribute. For me, it is negative, though its possible that, these days, Im in the minority here. I further realize that I may not be hearing the Cinemag at its very best, since it is not easy to optimize the load (which can be done by soldering in resistors), but my cartridge and phono stage were also known in advance by the manufacturer. So what do I advise If the unit, as I described above (and there are other reviews of it on various websites), still interests you, then I would directly contact Bob Sattin (bobsdevices ). Considering that Bob loaned me this unit for 20 months() . and without any complaint I might add, Sattin is obviously a reasonable person to deal with. He also has alternative SUT models from both Altec and Sowter . along with the Zu-Denon 103R . Odds and Ends - I broke in the CineMag for around 300 hours before I played it. It also has a gain switch (with two positions) as well as a ground lift switch. It was dead quiet, and I never had a problem with hum. For instance, in contrast to what I wrote above, it received rave reviews at Stereophile (Art Dudley, Listening 90) . as well as: 10audiobobsdevicesstepup. htm I rarely take this long to get to something, but an avalanche of unexpected components, plus historically poor weather, and component breakdowns, changed my schedule numerous times during this period. ( 1010 ) CAVEAT - Please be advised that the readers letters posted on this site are solely the opinion of that reader and may not necessarily represent or reflect the opinions of Arthur Salvatore or High-End Audio. These letters furthermore, are not to be taken as being endorsed by Arthur Salvatore or High-End Audio. They are posted because they may be edifying, thought provoking or entertaining. BENT SILVER TX-103 TRANSFORMER - I recently received an e-mail from a long-time reader and contributor . Thorsten Loesch . with news of a different version of this superb transformer, plus other components from the same source. Here it is: Just a note or two for you. Music First Audio . a subsidary of Stevens Billington . manufacture a fully featured step-up unit of my design around the TX-103 (silver is available on request), including switch adjustable loading and step-up, as well as a most excellent passive preamplifier based around transformers (again mostly my design - the background sketch on the front page is an early drawing of the circuit for it): While more expensive than Bent Audio product by the simple fact that, unlike Bents direct sales, Music First Audio Products are distributed through normal distribution and dealer channels they do offer a different take. Personal Note - I like options, so this is more good news for audiophiles. Conrad Johnson Premier 6 MC Step-up Heres some useful information from a reader about tube replacements for this reference step-up. . I have been usingloving one for about a year now and thought you should know that the tubes (4 x 6CW4 Nuvistors or 6SD4 ) are very readily available NOS on ebay even today, and they are fairly cheap too, 10-20 a piece. I am using 4 RCAs and the analog sound is really great, much better than any of the solid state stepup units or transformers I have tried ( Naim, PS Audio, Denon etc). Another nice thing about the Premier 6 is the cartridge loading can be set internally with plug in resistors anywhere from 2K ohms to about 10 ohms. And yes, you were correct, the main circuit board floats via rubber bands to eliminate any possibility of tube microphonics messing up the sound. (108) A veteran reader sent me his latest observations. Here it is, with some minor editing and my bold : . Finally, I wanted to let you know of an incredible bargain in the domain of stepups: the K K Audio MC phono Step-up . Ive had it for a couple of months now and have spent quite a bit of time comparing it with the ZYX CPP-1 . which I was using previously. Although the KK costs (far) less than the ZYX ( 290 in kit . 350 assembled ) and based on Lundahl transformers ( kandkaudiophonostage. html ), its actually better, in particular in the areas of clarity, frequency extension and inner detail. The ZYX is really lovely tonally, specially with piano and other single acoustic instruments (violin, cello are very good). The KK seems a little thinner at first, but its just a different timbral quality not harsh, certainly, just a bit lighter. In comparison, the ZYX sounds like it has a hump in the mid-bass which brings a bit of congestion. Indeed, where the KK really shines is as soon as the texture gets denser, because it allows for a clearer view inside the instrumental combinations, with more air between instruments and registers, so that polyphonic lines or even individual notes in harmonies are easier to differentiate. (Comparison made with a ZYX Airy 3 and the new Hagerman Trumpet at either end of the step-up. The load in my KK is 120 Ohms (20 KOhm resistor), and it has 20dB of gain, but it can be ordered in other configurations of load and gain.) The Trumpet is actually quite a hard unit to beat. I have the opportunity recently to test the Artemis Lab PH-1phono preamp . and after many attempts at optimizing it with various loading resistors, I couldnt get rid of some harshness in the treble it did actually sound better with the ZYX CPP-1 than the KK step-up, but I suspect it was because each units faults were somehow compensating each other. The KKTrumpet combination has more transparency, natural tonality and detail and its a lot quieter, too. Still, Im wondering how the Trumpet would fare against the KK phono preamp. (708) Some Cinemag Observations A long-time reader . who is also an audio manufacturer . periodically sends me some of his latest observations and thinking about various subjects. I removed the material that may have conflicts andor sensitivities, but the remainder is still quite interesting and potentially highly valuable, with my bold as usual: I just want to pass on a few observations and suggestions, based on your recent updates. Regarding the CineMag step-ups that are packaged by Bobs Devices . based on the 10 Audio review, Im sure that Bob has made no provision for adjusting the loading resistor. Jerry mentions that while he likes the sound in general, he says its really stunning with the Denon DL-103R . This makes sense, since that cartridge has a 14 Ohm internal impedance and, with the CineMag, is looking for a 47K Ohm phono load. That just happens to be the default resistor which almost every phono circuit uses, so no load adjustment is required. However, the lower the internal impedance of the cartridge, the lower the phono load needs to be. Otherwise, the CineMag sounds too hard and bright. For my MoFi-branded Miyabi . which has a 2 Ohm internal impedance, a 10K load works best. Of course, thats based on the fact that I can remove the 47K resistor from my phono circuit completely and replace it with any other value. Since most 47K resistors are soldered in place, youll have to experiment when using one that parallels the 47K default. Unlike normal cartridge loading, gross steps, such as 5K or 10K between values, are fine enough. As a caveat, I also found that there is a synergistic relationship between the circuit and the CineMag that goes beyond proper loading. You may find that its character will change, with the phono circuit that its feeding. (0210) THE REFERENCE COMPONENTS The Supreme Recordings My Audio Philosophy If you have a question. or want audio advice andor consultation: Important Notice - As of October 1, 2012 . there is a minimum fee of 10 for me to answer a simple enquiry, which means any question that I can answer quickly without research. Anything else will cost more and I will accordingly provide quotes for approval. PayPal is being used for its convenience, universality and security. If interested, click on Ask Arthur . There are two exemptions to the payment fees. 1. Those readers who have provided an important service (usually information that was posted) to this website over the years. 2. Those situations where I feel that I overlooked something important andor was obscure in my post, and thus some necessary clarification is required on my part. That will always be gratis. I dont believe in being unfair or petty, especially to my own readers. Telephone Conversations - If a reader feels it is necessary to actually talk to me directly, this can be arranged if I also feel it is appropriate. There will be a minimum fee of 50 . Ask for the details before paying the fee. Finally, a veteran reader wrote that I should also have a link for (generic) donations to keep the website going . I replied that the Donation button can also be used by appreciative readers for that purpose. Needless to say, any unsolicited donation from a generous reader receives my sincerest thanks and gratitude. To contact me for any other reason: COPYRIGHT 1999-2016 ARTHUR SALVATORESource code available here: 8211 OpenCV Library ( At the time of this article I was using Version 1.1pre1, October, 2008) Once you have instaleld the libraries and downloaded the code open OpenCV-Qt-StereoVision. pro in QT Creator. Update the paths to where your OpenCV library is installed (replace every occurrence of C:SDKOpenCV to the path where you installed OpenCV). It is assumed that you have 2 USB cameras connected to your PC and there are no other cameras connected to computer. If this is not the case then you might want to have a look at StereoCamera::setup() in stereocamera. cpp. It is assumed your cameras can capture 640215480 images. If you don39t have the cameras yet, but would like to test the sofware using the included images sets (see images folder). Open mainwindow. cpp and comment out timer. start(50) while uncommenting one of the 2 lines: stereoVisionTest(quot..imagesset1quot,7,4) run test1 stereoVisionTest(quot..imagesset2quot,9,6) run test2 If you get any compiler errors make sure your Qt and OpenCV libraries are installed correctly. For that matter try to create a new test QT project and make sure it compiles. Before your cameras can see in 3D you need to perform a calibration sequence. 8211 print out the following PDF. ChessBoard 8211 Stereo Calibration. pdf and tape it to a solid piece of wood, plastic or fiber glass (make sure the image is not bent or calibration will not work). 8211 focus your cameras so that the text on the chessboard is readable, make sure you don39t modify the focus of cameras after calibration or during calibration since the focus is an important factor in calibration . 8211 start calibration by clicking on Start Calibration button in software, place the chessboard in front of the cameras so that it is completely visible in both cameras. - software will take samples every 5 seconds. until the specified number of samples has been taken (10 by default). - once calibration is complete click quotSave Calibrationquot to save calibration data to a file (calibration will be reloaded next time you start the program automatically). - if you modify position or focus of cameras you will need to calibrate. - pay attention to 39rectified39 image. if a line intersects an object or a spot on the left image it should intersect same object or spot on the right image. This is an indicator that your calibration is correct. - if you have valid calibration data you should see the normalized depth image in the quotDepthquot window IMPORTANT UPDATE July 3, 2010: Updated code to work with OpenCV-2.0.0a-win32.exe (will no longer work with older versions, unless you modify the. pro file, to include ther proper libraries and include paths). 35. john March 29, 2010 I would just like to ask how did you get the focal length Is it from the cameramatrix given by cvStereoCalibrate Which one did you use Fx or Fy for focal length I would also like to ask how did you get the disparity Is it the one that is being returned by cvFindStereoCorrespondenceBM then divided by 16 Sorry if I ask these questions because I am not getting an accurate result. ( I hope you can help me with this. 36. Fernando March 31, 2010 I use fx because disparity is measured in the x-axis. You should then divide the disparity from OpenCV by 16. And dont forget all the metrics from OpenCV matrixes are in pixels, so you will have to convert them into real units. Hope it helps you. 37. Fernando March 31, 2010 I forgot to say fx is from camera matrix and disparity map is from the stereoCorrespondence function. 38. john April 1, 2010 Thanks for your response. In your previous post you said f - focal length in pixels b baseline in CENTIMETERS (its used to convert from pixel world to cm world) d disparity in pixels (note that the disparity returned by Opencv is multiplied by 16, so you have to divide it for that in order to get the real disparity)8221 and eventhough I already converted all the pixel units to CM, I am still not getting the correct results. ( By the way, are you using Hartley8217s or Bouguet8217s algorithm in computing for the distance 39. Sh arad Shankar April 2, 2010 I8217ve been trying to compile your code. I8217m using the latest released QT SDK along with OpenCV 1.1Pre1a. I8217ve installed OpenCV at the location c:SDKOpenCV, so I wouldn8217t have to change the header and lib file locations. However, when I go to compile this program, I get the following error. Running build steps for project OpenCV-Qt-StereoVision8230 Starting: c:qt2010.02.1qtbinqmake. exe C:Documents and SettingsvcuDesktopOld stuffSeniorDesign2010(2)ShawnstereovisionOpenCV-Qt-StereoVision. pro - spec win32-g - r Exited with code 0. Starting: C:Qt2010.02.1mingwbinmingw32-make. exe - w mingw32-make: Entering directory C:Documents and SettingsvcuDesktopOld stuffSeniorDesign2010(2)Shawnstereovision8217 C:Qt2010.02.1mingwbinmingw32-make - f Makefile. Debug mingw32-make1: Entering directory C:Documents and SettingsvcuDesktopOld stuffSeniorDesign2010(2)Shawnstereovision8217 g - c - g - frtti - fexceptions - mthreads - Wall - DUNICODE - DQTLARGEFILESUPPORT - DQTDLL - DQTGUILIB - DQTCORELIB - DQTTHREADSUPPORT - DQTNEEDSQMAIN - I8221c:Qt2010.02.1qtincludeQtCore8221 - I8221c:Qt2010.02.1qtincludeQtGui8221 - I8221c:Qt2010.02.1qtinclude8221 - I8221c:SDKOpenCVcxcoreinclude8221 - I8221c:SDKOpenCVcvinclude8221 - I8221c:SDKOpenCVcvauxinclude8221 - I8221c:SDKOpenCVotherlibshighgui8221 - I8221c:Qt2010.02.1qtincludeActiveQ t8221 - I8221debug8221 - I8221.8221 - I8221c:Qt2010.02.1qtmkspecswin32-g8221 - o debugmain. o main. cpp mingw32-make1: Leaving directory C:Documents and SettingsvcuDesktopOld stuffSeniorDesign2010(2)Shawnstereovision8217 mingw32-make: Leaving directory C:Documents and SettingsvcuDesktopOld stuffSeniorDesign2010(2)Shawnstereovision8217 In file included from stereocamera. h:5, from mainwindow. h:5, from main. cpp:2: c:SDKOpenCVcxcoreincludecxmisc. h:133:6: error: elif with no expression mingw32-make1: debugmain. o Error 1 mingw32-make: debug Error 2 Exited with code 2. Error while building project OpenCV-Qt-StereoVision When executing build step 8216Make8217 I8217m not sure how to fix this error: elfif with no expression Please advise me on this problem, thank you very much. 40. Philip Dodson April 5, 2010 Had the same issue as you Sharad, but looking it up online, I replaced elif with else per this page ai. stanford. edu sgouldsvlfaq. html. I am now getting another error, however: 8220collect2: ld returned 1 exit status8221 apparently due to it saying RESULTOK and RESULTFAIL are called used without being defined around line 49. Not sure why it would say this, I am not too keen on C and am kind of confused by how the code is used here. Would greatly appreciate your help This is my compiler output: debugstereocamera. o:C:Documents and SettingsvcuDesktopOld stuffSeniorDesign2010(2)Sharadstarlino opencvstereovisionopencvstereovision-read-onlystereocamera. cpp:49: undefined reference to StereoCamera::RESULTOK8217 debugstereocamera. o:C:Documents and SettingsvcuDesktopOld stuffSeniorDesign2010(2)Sharadstarlino opencvstereovisionopencvstereovision-read-onlystereocamera. cpp:49: undefined reference to StereoCamera::RESULTFAIL8217 collect2: ld returned 1 exit status mingw32-make1: debugOpenCV-Qt-StereoCalibration. exe Error 1 mingw32-make: debug Error 2 Exited with code 2. Error while building project OpenCV-Qt-StereoVision When executing build step 8216Make8217 41. Starlino April 9, 2010 RESULTOK, RESULTFAIL are defined in stereocamera. h, static int const RESULTOK 0 static int const RESULTFAIL 1 you may change those constants with actual values, maybe the compiler version you8217re using is having problems getting into clas s constants, or maybe there8217s a inclusion problem with stereocamera. h. Anyways try replacing those values with 0 1. And if you still get errors for other things defined in stereocamera. h, then it8217s definitely a problem wit the include. so change return (captures0 038038 captures1). RESULTOK. RESULTFAIL return (captures0 038038 captures1). 0. 1 Let me know your findings. Please share the results with others. Thanks 42. Philip Dodson April 11, 2010 Changed RESULTOK to 0 and RESULTFAIL to 1 everywhere in stereocamera. cpp and it works perfectly This is going to save our lives for our senior design project Thank you Starlino, you are the man 43. PP April 18, 2010 I8217m doing a depth extraction research for my studies and i have some problems. I wrote a program using opencv which is working well on windows, but it only works with 1 usb webcam and 1 built in laptop working simultaneously, but they are too different, so the effects are poor. I can8217t get 2 usb webcams working together on windows (not even in other programs, not using opencv). So i tried to run the program on linux (Ubuntu 9.10) but now i have other problems, i cant get any 2 webcams to work together. They work ok separately, but when i try to use them together i get things like this img532.imageshack. usimg5322734beznazwygn. jpg 8230 Now i have only 2 weeks left for it and i can8217t get it working, so i thought maybe you have any stereo movie recorded (with images from 2 cams, one to another on one movie, or 2 movies, each from another cam, synchronised) with chessboard recorded, so it can be used for stereo calibration algorithm, and to depth extraction I found some stereo movie samples with other objects on it, but without callibration, estimated depth map isn8217t satisfactioning. If you have anything like this you could give me, or you can help me with using two webcams (code is allright, problem is somewhere else), i would apreciate it. Takk. 44. Philip Dodson April 24, 2010 I hope my previous comments helped someone out there. But now I ask, has anyone successfully ran this in Visual Studio I need to get a depth map working in Visual Studio 2003, because I am using a library called Matrox Imaging Library, which the QT compiler seems to have a problem with. Also, all of my old code was written in Visual Studio, so it would be a pain to move it to QT creator. If anyone could provide an explanation of how to get it working in ANY version of Visual Studio, that would be somewhat helpful. Would it be possible for me to simply copy the code and take out all the QT interface stuff Semesters almost over8230running down to the wire, help would be very much appreciated, you know, per the usual. 45. tharindu May 24, 2010 I have managed to get through most of the compiling errors. but now it is exits with a exception, C:Documents and SettingsUOMDesktopDepthmapdebugOpenCV-Qt-StereoCalibration. exe exited with code -1073741515 ....Qt2010.02.1qtmkspecswin32-g8221 - DGNUC - DWIN32 mainwindow. h - o debugmocmainwindow. cpp g - c - g - frtti - fexceptions - mthreads - Wall - DUNICODE - DQTLARGEFILESUPPORT - DQTDLL - DQTGUILIB - DQTCORELIB - DQTTHREADSUPPORT - DQTNEEDSQMAIN - I8221........Qt2010.02.1qtincludeQtCore8221 - I8221........Qt2010.02.1qtincludeQtGui8221 - I8221........Qt2010.02.1qtinclude8221 - I8221........SDKOpenCVcxcoreinclude8221 - I8221........SDKOpenCVcvinclude8221 - I8221........SDKOpenCVcvauxinclude8221 - I8221........SDKOpenCVotherlibshighgui8221 - I8221........Qt2010.02.1qtincludeActiveQt8221 - I8221debug8221 - I8221.8221 - I8221........Qt2010.02.1qtmkspecswin32-g8221 - o debugmocmainwindow. o debugmocmainwindow. cpp g - enable-stdcall-fixup - Wl,-enable-auto-import - Wl,-enable-runtime-pseudo-reloc - mthreads - Wl - Wl,-subsystem, windows - o debugOpenCV-Qt-StereoCalibration. exe debugmain. o debugmainwindow. o debugstereovision. o debugstereocamera. o debugstereovisiontest. o debugmocmainwindow. o - L8221c:Qt2010.02.1qtlib8221 - lmingw32 - lqtmaind C:SDKOpenCVlibcxcore. lib C:SDKOpenCVlibcv. lib C:SDKOpenCVlibcvaux. lib C:SDKOpenCVlibhighgui. lib - lQtGuid4 - lQtCored4 mingw32-make1: Leaving directory C:Documents and SettingsUOMDesktopDepthmap8217 mingw32-make: Leaving directory C:Documents and SettingsUOMDesktopDepthmap8217 Exited with code 0. Any help would be greatly appreciated82308230. By the way im a QT newbie8230:) 46. tharinduwije May 25, 2010 stalino, the code is exsiting with 821608217 Starting C:Documents and SettingsUOMDesktopDepthmapdebugOpenCV-Qt-StereoCalibration. exe8230 C:Documents and SettingsUOMDesktopDepthmapdebugOpenCV-Qt-StereoCalibration. exe exited with code -1073741515 Running build steps for project OpenCV-Qt-StereoVision8230 Starting: C:Qt2010.02.1mingwbinmingw32-make. exe - w mingw32-make: Entering directory C:Documents and SettingsUOMDesktopDepthmap8217 C:Qt2010.02.1mingwbinmingw32-make - f Makefile. Debug mingw32-make1: Entering directory C:Documents and SettingsUOMDesktopDepthmap8217 mingw32-make1: Nothing to be done for first8217. mingw32-make1: Leaving directory C:Documents and SettingsUOMDesktopDepthmap8217 mingw32-make: Leaving directory C:Documents and SettingsUOMDesktopDepthmap8217 Exited with code 0. Configuration unchanged, skipping QMake step. Program is not running any idea 47. Gizmo June 3, 2010 From the sounds of it, the problem that I am having is the same as PP I am not able to use two USB cams at once. tharinduwije said that he was able to compile but not run the program, which is the current state that I am in whenever I try to use two external cameras. I can compile the program fine, with the same output that he has, but when I try to run the program using two USB cameras, it crashes every time, claiming that an incorrect size of input array (non-positive cols or rows) existed in function cvInitMatHeader. cxarray. cpp(182) I have one built-in webcam and two external USB cams. If I use my built-in cam and one of the USB cams, the program runs fine however, any time I have the program attempt to use both USB cams at the same time, I get that error. I am thinking that it may be a problem because I have both of the cameras on the same USB hub. The external cams are connected through my computer8217s USB ports, which are all part of the same single hub (hub 0), but my built-in webcam is a USB device on the hub that only contains built-in things (hub 1). If having the cams on the same hub prevents the stereovision from working, then that8217s probably my problem. However, rbha311 claimed to be having problems with limited USB bandwidth if having the cams on the same hub is only an issue because of the possibility of using too much bandwidth, I doubt that it8217s an issue for me. Though it8217s possible that I could have a similar problem, no messages have informed me of any problems from using too much bandwidth, and when I check during any other operation of the cameras and other USB devices simultaneously, there is no lack of bandwidth. Anyone understand this and have any ideas to fix it 48. Starlino June 3, 2010 To see if you cameras can be open at the same time try a different software, for example: For Windows check out DirectShow samples, that can be useful in troubleshooting the problem (might give you more info than the compiled software above): Knowing in advance that you cameras can stream at once is a good starting point. Also try USBDeview nirsoftutilsusbdevicesview. html to see if your cameras are actually detected, you can also check if they have a serial associated. Some drivers will get confused unless similar devices with same usb VIDPID have a serial number. I guess there8217s little you can do if you discover you can8217t have same model of camera attached at the same time, other than probably somehow route it through a different computer, or just get a new set of cameras. Also try to connect it to a different hub. Be aware that some USB ports on your computer belong to the same usb hub on the motherboard. 49. Gizmo June 4, 2010 I found out that my problem was due to the limited bandwidth available on my USB hub. I had verified before that I could have both cameras capturing video at the same time, and I had taken a look using USBDeview to see if there were any problems there. I also checked the bandwidth usage, but like I said in my last comment, I didn8217t think that was a problem. Jeg tok feil. When the program tried to start both cameras, the camera that was started first would display it8217s image in one of the rightleft windows, and would take 69 of my available USB bandwidth. Then when the other one tried to activate, it only had access to 17 (my USB mouse was consuming the remaining 14). This was fine every time I tested having them active at the same time, and even capturing video from the both at the same time. However, it is evidently not enough for the stereo vision program to run effectively. As such, the rightleft window for the second camera would display no image, and the program would crash. I did finally get it working, though. I could not get my cameras to evenly distribute the available bandwidth 5050, but I did reduce how much they should be able to use. The most I could get them to do is have one take 57 of the available bandwidth and the other takes 43. I couldn8217t force them to go lower, nor could I force them to divide it evenly. However, this is enough that the program doesn8217t crash and the cameras are operating almost identically. 50. steven June 8, 2010 im trying to compile all of your project but in the end i got this eror result C:UsersStevenDesktopstereovissionOpenCV-Qt-StereoVisionstereocamera. cpp:29: error: 8216CVCAPDSHOW8217 was not declared in this scope is the problem within my openCV library if it is could you guide me through chaning my library to a correct one, because i still new in using opencv and Qt, 51. ugur June 16, 2010 firstly, thanks for this great job. But :) I8217m not able to run project :( Output: Starting C:UsersuurDesktopstereovisionstereo vision ExampledebugOpenCV-Qt-StereoCalibration. exe8230 Invalid parameter passed to C runtime function. Invalid parameter passed to C runtime function. C:UsersuurDesktopstereovisionstereo vision ExampledebugOpenCV-Qt-StereoCalibration. exe exited with code 3 Can I do something wrong Since I do not know anything for QT. I just downloaded, build and run it. 52. Simone June 27, 2010 HI, i have a problem, when i try the calibration IplImage StereoCamera::getFramesGray(int lr) if(frameslr) return 0 if(frameslr-depth 1) framesGraylr frameslr return frameslr else if(0 framesGraylr) framesGraylr cvCreateImage(cvGetSize(frameslr),IPLDEPTH8U,1) cvCvtColor(frameslr, framesGraylr, CVBGR2GRAY) return framesGraylr i recive a runtime error. in particular in this pointcvCvtColor(frameslr, framesGraylr, CVBGR2GRAY) the error is 8220the inferior stopped because it recived a signal from the operation system sig nal name: SIGSEGV signal meaming: Segmantation fault8221 can you help me 53. Luiz Henrique July 20, 2010 Having some troubles compilingfinding libraries. Platform: MacOS 10.6.4 My. pro file: (I have commented out all LIBS options, since none are working) Thanks for any help G 8212821282128212821282128212821282128212821282128212821282128212- Project created by QtCreator 2009-06-25T18:55:22 8212821282128212821282128212821282128212821282128212821282128212- TARGET OpenCV-Qt-StereoCalibration TEMPLATE app OpenCV LIBS optlocalliblibcv. dylib LIBS optlocalliblibcvaux. dylib LIBS - lcv LIBS - lcvaux - lhighgui - lml SOURCES main. cpp mainwindow. cpp stereovision. cpp stereocamera. cpp stereovisiontest. cpp HEADERS mainwindow. h stereovision. h stereocamera. h uimainwindow. h FORMS mainwindow. ui 59. sandy August 18, 2010 hiii first of alll thanks a lot for posting this project online, this helped me alot. i wanted to ask that i m using a single ccd camera which is capturing two images by using prism and mirrors. so the image which i am getting in camera is made up of two images left and right. for images it becomes very easy as i can crop images and the use them for matching. but if i have to make it real time hw can i do it. as i am looking for crop video softwares aswell but cant find anything. thanks a lot for helping me 60. starlino August 23, 2010 sandy, I think OpenCV has basic functionality for cropping an image, the camera function used in this software simply gets 2 8220Frame8221 objects that are images. In your case i guess you would get just one frame then use a ROI (region of interest) to extract the 2 images, see for example here nashruddinOpenCVRegionofInterest28ROI29 61. sandy August 24, 2010 thanks a lot starlino for helping me8230 i got that part by setting both capture to one camera and then using ROI on both of them. but another trouble is frames after roi are not coming to be 640215480 i have to resize them so that i dont have to makes in rest of files. i been searching methods to resize ipl images but still till now i havent got any luck, can u suggest me any appropriate method for this thank you. 62. sandy August 24, 2010 hiii when i am trying for calibration after 5 seconds completion softwares freezes and it is giving error of signal SIGSEGV and saying segmentation fault could you help me with this please thank you 63. santhosh chaitanya October 18, 2010 Hie , I an using QT sdk 4.7 version and opencv 2.1 and windows xp. when the compile the. pro file it compiles successfully when the programme runs, the error connecting to camerasfailed appears in the plainTextEdit. I have checked that both of my zebronic webcams are working perfectly fine. and also I tried increasing the index values in stereocamera. cpp nothing happens. I also tried to execute the program with test images provided in set 1 folder of the code folder. i followed the above said instructions If you don8217t have the cameras yet, but would like to test the sofware using the included images sets (see images folder). Open mainwindow. cpp and comment out timer. start(50) while uncommenting one of the 2 lines: stereoVisionTest(8220..imagesset18221,7,4) run test1 stereoVisionTest(8220..imagesset28221,9,6) run test2 when it complie the project it compiles successfully but some unexpected error occurs and the program crashes indicating as below C:OpenCV-Qt-StereoVision-build-desktopdebugOpenCV-Qt-StereoCalibration. exe exited with code -529697949 please help me out in this part. thnx in advance. 64. Iqra November 9, 2010 i am getting this error at build time..please tell me whats the issue . error: No rule to make target stereovision. cpp8217, needed by tmpobjdebugsharedstereovision. o8217. Stoppe. 65. Iqra November 11, 2010 i am getting this error at run time Starting C:Qt2010.05qtOpenCV2.0OpenCV-Qt-StereoVision-build-desktopdebugOpenCV-Qt-StereoVision. exe8230 C:Qt2010.05qtOpenCV2.0OpenCV-Qt-StereoVision-build-desktopdebugOpenCV-Qt-StereoVision. exe exited with code -1073741515 66. Stereopsis November 22, 2010 I had a problem when i did calibration by using opencv library as your suggestion. I try to calibrate with farther distance(20m) and larger chessboard (2 x 1 meter). The library can detect the corners for left and right images, but it can not generate rectified map correctly. Do you have any suggestion for my situation thanks in advance for your reply. 67. santhosh chaitanya December 1, 2010 Hie everyone , I am using QT sdk 4.7 version and opencv 2.1 and windows xp. when the compile the. pro file it compiles successfully when the programme runs, the error connecting to camerasfailed appears in the plainTextEdit. I have checked that both of my zebronic webcams are working perfectly fine. and also I tried increasing the index values in stereocamera. cpp nothing happens. I also tried to execute the program with test images provided in set 1 folder of the code folder. i followed the above said instructions If you dont have the cameras yet, but would like to test the sofware using the included images sets (see images folder). Open mainwindow. cpp and comment out timer. start(50) while uncommenting one of the 2 lines: stereoVisionTest(..imagesset1,7,4) run test1 stereoVisionTest(..imagesset2,9,6) run test2 when it complie the project it compiles successfully but some unexpected error occurs and the program crashes indicating as below C:OpenCV-Qt-StereoVision-build-desktopdebugOpenCV-Qt-StereoCalibration. exe exited with code -529697949 please help me out in this part. please suggest me which version of opencv and QT to use to get the program compiled successfully. I am stuck at this point from many days. please help me out8230 68. Erkable December 2, 2010 What model cameras are you using
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