Today i found this amp in a not so great state, but it was about 3 dollars so i couldn't resist.Looking at its schematic i saw some interesting features as being a dc amp its thermal stability is important, but the things that set this thing apart in my limited view were the first two antisaturation diodes which were distributed in the first two stages instead of being placed in the first stage.Can anyone shed a more comprehensive theoretical light over this circuit?
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Audiophile compact vintage Philips 22AH309 stereo power amplifier (1980).
The Philips 22AH309 power amplifier delivers 55 watts per channel (8 ohm).
3 LTP + 2EF. 0 balance. Bias.
The Philips 22AH309 power amplifier delivers 55 watts per channel (8 ohm).
3 LTP + 2EF. 0 balance. Bias.
To be honest I like this concept...Unfortunately it's quite difficult to make it work right now.I had to dissasemble it completely to have a thorough wash...Even so, the way its designed and the quality of the components is really good .
TS613a/615a are refferenced to the output zero bias while Ts 614a/616a are refferenced to the dc ground sensing the DC output balance .
both pair are doing the same thing ,just one is most efective in dc and the other is most effective in ac.c618a/c619a tells a lot about that .