Hi Everyone,
I was lucky to get two Sansui OPT's and a PSU trafo from a friend. They were sitting on a shelf in his garage, collecting dust.
Anyway, the OPT's are the same ones that were used in the Sansui AU-111. (410-5235) Originally, they were used with 6L6GC's in PP. They don't have UL taps, but have a 10% Cathode Feedback winding. Primaries are 4K, secondaries 16 and 8 Ohm. Power rating is 50 Watt.
The PSU trafo is not from an AU-111. Secondaries are: 0-330V, 0-330V, 0-87V, 13-0-13V, 0-6.3V. VA rating is unknown.
I have been contemplating triode strapping EL34's. But my speakers are 88dB sensitive, so I probably need more power. Alternatively, I could just build an AU-111 clone. (power amp only). But this calls for 485 Volt on the plates. I could get a Sansui PSU trafo copy made, but would like to use my 330V iron. Can the current production 6L6GC's handle 485V well? Could I perhaps use the CFB with EL34's in pentode mode?
As a relative newbie, my mind is spinning. I would love to hear your recommendations. I've posted this question at AA, and got interesting replies. But I still feel unsure...
Thanks in advance,
Chris
I was lucky to get two Sansui OPT's and a PSU trafo from a friend. They were sitting on a shelf in his garage, collecting dust.
Anyway, the OPT's are the same ones that were used in the Sansui AU-111. (410-5235) Originally, they were used with 6L6GC's in PP. They don't have UL taps, but have a 10% Cathode Feedback winding. Primaries are 4K, secondaries 16 and 8 Ohm. Power rating is 50 Watt.
The PSU trafo is not from an AU-111. Secondaries are: 0-330V, 0-330V, 0-87V, 13-0-13V, 0-6.3V. VA rating is unknown.
I have been contemplating triode strapping EL34's. But my speakers are 88dB sensitive, so I probably need more power. Alternatively, I could just build an AU-111 clone. (power amp only). But this calls for 485 Volt on the plates. I could get a Sansui PSU trafo copy made, but would like to use my 330V iron. Can the current production 6L6GC's handle 485V well? Could I perhaps use the CFB with EL34's in pentode mode?
As a relative newbie, my mind is spinning. I would love to hear your recommendations. I've posted this question at AA, and got interesting replies. But I still feel unsure...
Thanks in advance,
Chris
Attachments
KT88
Thanks for the advice everyone.
I am quite attracted to KT88's. Poobah, do you mean KT88's in triode mode? I can source KT88EH tubes locally, but am wondering if JJ's would not be a better bet.
What driver/phase-splitter circuit do you recommend? "The Ultimate PP KT88 Amp" driver looks nice, but calls for 480V. I have a few nice 6SN7's for this application.
http://www.plitron.com/pages/Products/Audio/vtvkt88.htm
Anyone have experience with the 6L6EH? Would it handle the 485V in an AU-111 clone?
My dilemma: Building an AU-111 clone calls for a new PSU trafo. Using my 0-330V iron would free up money for more costly KT88's.
Chris
Thanks for the advice everyone.
I am quite attracted to KT88's. Poobah, do you mean KT88's in triode mode? I can source KT88EH tubes locally, but am wondering if JJ's would not be a better bet.
What driver/phase-splitter circuit do you recommend? "The Ultimate PP KT88 Amp" driver looks nice, but calls for 480V. I have a few nice 6SN7's for this application.
http://www.plitron.com/pages/Products/Audio/vtvkt88.htm
Anyone have experience with the 6L6EH? Would it handle the 485V in an AU-111 clone?
My dilemma: Building an AU-111 clone calls for a new PSU trafo. Using my 0-330V iron would free up money for more costly KT88's.
Chris
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