Strange idea for an output stage - comments requested

[Tetrode]

I think sometimes we build weird stuff just for the sake of being weird.

This is one of those times.... BTW,I know this because i've been there many times.....

I think your better off using the 6l6's as tetrodes(easier to drive,better PSRR)and adding a stable GNFB loop.

Lose the 6N1p's(they sound like bad SS devices to me) and use your garden variety 9 pins or octals.

Built well and with a good OPT it can hang with ANY good tube or SS amp.

 

[TVC]

http://www.anc-tv.ne.jp/~suzuki3/amp_6sl7_300bpp_rofchin/k_6SL7_300Bpp_Amp.pdf

This schematic will be of your interest. You can find it on a Japanese DIYer's website. As the website says in Japanese (sorry), the original design of this SE-PP switchable class-A 300b amp was actually published by Mr. Takaaki Uzike (or Ujike) in a couple of issues of RADIO GIJYUTSU magazine (a monthly Japanese DIY magazine like MJ) in 2000. In the articles, he says he developed the circuit and assembled his 300b amp, in order to make the best use of Permalloy PP output transformers, and named this output stage configuration "floating OPT", which I think is equivalent to "parafeed PP". Mr. Uzike used a pair of Tango NY-45-5 (discontinued).

Yoshi

-------------

recently I got this pair and prepare for my 300B PP, but will start with EL34 PP to try it first.

thx

TVC

 

[Sch3mat1c]

Geez, 45W permalloy, those things must be worth, about their weight in 300Bs?!