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Sorry to hog the threads but does anyone have experience with the Williamson Amp?
I've built a couple, and fixed scores of them. Whadya wanna know?
Thanks for the help. In the driver stage do you like 6sn7 or 12au7's? How much feedback? What kind of bias? And last, phase-splitter; concertina? How do feel about 807 power tubes? I would like to try putting one together thats why I ask. Again thanks,J.R.
OK, if you must: 6SN7s about 10-15 dB Fixed (negative grid) bias I would stick to the classic circuit. Don't mess with it unless you are familiar with designing differential amplifier stages. 807s are great. The cheap Chinese ones aren't, but NOS are still relatively easy to find. 6550s or KT88s are even better--more gain, tougher screen grid.
Thanks much; not a big fan, eh?
>not a big fan, eh? How do you mean? It's a classic topology. But depends heavily on a good output transformer. Don't skimp on that. In fact, if you want a really good version, I recommend the John Eckland designed KT88 amp project in VTV issue 19. It uses Plitron transformers. I can attest to its excellence, having heard it (with a variety of classic speakers).
I just assume any decent amp depends on the opt and of course would get the best within reason. Plitron is fine by me, is that amp on the plitron site? I know that Memmo VanDevere does one similar to that amp. May I ask how the amp does with very efficient, well damped bass-reflex woofers?
It works extremely well with any kind of speaker. Bass enjoys considerable damping, without sounding like a soiled-state amp. No that amp isn't on the Plitron site. Sorry, you have to get that issue of VTV. The owner of VTV expects to get paid, so support him and be nice.
No problem there I have every issue, and I buy retail! Matter of fact I can probably qoute you from issues you forgot about. Thanks for your help, J.R.