looking for the top 6080 amp schematics

[diesel_tech]

I've got 4 6080WC tubes stamped JAN. I've been looking for a circuit to use these. What do you use and how do you like it, i'm looking for simple P-P with 12AX7, 6SN7 or similar for the driver. Any suggestions?

Thanks
Jeremy

[Shoog]

My design philosphy for the 6080 is run them hot and low ie 100V (plate to Cathode) and 100mA. Bias them up with CCS to overcome their intrinsic mismatch issues. I have successfully used cheap main toroidals as outputs in this configuration. This will give you about 7W per PP pair in class A. I have also generally cap coupled the cathodes together for differential operation rather than referencing to ground.
Others will tell you to run them at higher voltages and lower currents, which makes the design of power supply and selection of output transformer easier. However I feel hot and low sounds better.
Front end would always be a LTP and I would be inclined to include a input transformer to maintain maximum gain from the LTP. If you run the outputs at the setting I suggest then you only need 60V ptp of drive from the front end - which will be very doable with just the front end LTP and something like a 5687.
This configuration will perform adequately well with no gNFB, but you can introduce a little back to the LTP if you feel it is needed.
Overall this makes for a lovely 2 tube per channel 7W class A beauty.

Shoog

[monyse]

In my opinion one of the best 6AS7/6080 schematics I encountered is Wim de Haan's from the N

[monyse]

Sorry for previous incomplete message ; Wim de Haan is from Neederland ; you can goggle his name or tape his site www.wimdeham.nl

monyse

[Jaap]

works better

6080 is also used in a good regulator by Jan Didden as published in Elektor this month. See also this forum.

[grhughes]

because of it's low mu. Unit to unit they are all over the place along with the 12b4a. Makes a great pass tube in a power supply which is what it was designed for.

[Shoog]

My experience is that if you can keep the standing current stable (with CCSinks), the tubes behave well and stay well behaved until the CCSinks can no longer maintain balance - at this point they begin to oscillate.

Shoog

[dave_gerecke]

Since the 6080 is the "industrial" grade version of the 6AS7, and the 6AS7 is popular for building OTL amps, you could try that. The design by Bruce Rozenblitz published is GlassAudio back in the early nineties is one thought.

Peace,

Dave

[gain-wire]

Well imagine that...
about ten years ago, I decided to use MY 6080WBs for an audio amplifier project. I did it single-ended, though, with a transformer that I chose for its looks , (I know, stupid, I was young) and ran the whole thing at 30 volts. It worked!
I don't think I had more than 3 watts, but I wasn't looking for power. The driver was a Dynaco PAT-5 preamp. how bout that, solid-state driving tubes! It worked good enough for me...

Probably if the Dynaco put tout more than 2V R.M.S., I could have gotten more output signal.

that dynaco sold on ebay...