Greetings, Something to share with all TA lurkers. Took this thread off RAT(rec.audio.tubes) newsgroup about 6SN7 sound performances. Enjoy. Regards. ::-) ---------------------------------------------------------------------------- (beginning of original message)
Subject: Re: 6SN7 sound performance From: chimera1@idt.net Date: 1999/03/26 Newsgroups: rec.audio.tubes Glad everyone enjoyed the first sound performance opinions. The key work is opinions. This is an update on the sound performance of the vintage 6SN7 types. I have added all the customer feedback on how the various tubes sounded in their system. Let me stress that the optimum tube for your system will depend on your equipment and how your ears judge the tube's ability to reproduce live music. The general consensus is that the vintage 6SN7 types, especially the VT-231s, sounded better than 5692s. I must add that the 5692 is a very quiet tube, if you have equipment where 6SN7 tubes are microphonic, a 5692 may be the best choice. Only one customer who had problems with microphonics(CSL-6SN7-WGT long plate with metal band). The Sylvania long plate 6SN7WGTs & 6SN7WGTAs have received very favorable reviews. Work great as a driver or cathode follower. They also seem to "wake up" tube gear that sounds a little soft or slow. A few customers preferred these tubes to the VT-231s in this case. I want to caution everyone that various 6SN7 types have different voltage and plate dissipation ratings. The voltage rating refers to voltage across the tube's plate and cathode. To ensure good tube reliability you should probably run a tube at 70% or less of its maximum plate dissipation. 5692 - 275 Volts maximum & maximum 1.75 Watts per section 6SN7GT/WGT -- 300 Volts maximum & maximum 3.5 Watts per section 6SN7GTA/GTB - 450 Volts maximum & maximum 5.0 Watts per section Using the tube service recommendations of 250 plate volts, a bias of 8 volts results in 9ma of current and a plate dissipation of 2.25 Watts. 5692 - runs 43 % over maximum rating 6SN7GTB/WGTB - runs 64% of maximum 6SN7GTA/GTB - runs 45% of maximum I know the 5692 is considered a "10,000" hour tube, but years of audio fans trying them in circuits designed to run 6SN7GTs in a low distortion linear mode may be why they are so rare and expensive. The 5692 service recommendation recommends 250 Volts, -9.0 volt bias and 6.5 ma current for a plate dissipation of 1.625 Watts or 93% of maximum. That's still seems pretty "hot" for long tube life. Here are the rankings. If you have anything to add, email me and I will add it to the list. Yes I still have some stock of these tubes left. No I have changed my prices based on the new performance evaluations. Email me and I will send you the current list. VT-231 Tungsol, round black plates - Clean, fast, the best in everything VT-231 Raytheon, black flat plates - like the Tungsol a little sweeter VT-231 RCA, black plates, rich harmonics like a 5692, wide soundstage VT-231 Ken-Rad, flat black plates - Great Bass, drive, sweet midrange VT-231 National Union - good drive and great midrange, softer bass VT-231 Sylvania, black plates, wide bandwidth, delicate & laid back 6SN7WGT, Sylvania Metal rim, big tube, big sound, super soundstage 6SN7WGT, Sylvania, Long Plate, same big tube minus the metal rim 6SN7WGT, Syl Standard Black Plate, transparant, images very well 6SN7WGT, Syl Green Label, like the Standard but front row center 6SN7GTA, General Electric Black Plate, the great driver tube? 6SN7WGTA, Syl black base green label, another great driver tube 6SN7GT, CBS Black Plate, very good tube, quiet, and musical 6SN7GT, Sylvania or RCA Black Plate, very good and easy to find 5692, CBS-Hytron, fast, good dynamics, lot of air and great timbre 5692, RCA Red Base, very warm sweet sound, great on voices and jazz 6SN7GTB, RCA, sounds like a 5692 with slight veiling 6SN7GTB, Syl, like the Syl militaries but not as focused or quiet 6SN7GTB, G.E, Gray plates, work horse, lacks refinement, a good tube Best Regards, Dennis Dennis Boyle, email chimera1@mail.idt.net Chimera Laboratories - www.ChimeraLabs.com/~CL/ 1414 South Akard Street Dallas, TX 75215 TEL: 214-428-3901 FAX: 214-426-6605 (end of original message) ----------------------------------------------------------------------------
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