The Amp Garage

it’s not good to run a electrolytic that far under its rated voltage because they will not stay formed and there life will be shortened by some 25%. If you could direct me to some reference material that describes this effect, I would like to learn more about it. I have read a few papers on deratin...

lonote wrote: ↑Fri Apr 18, 2025 4:22 pm

Is that is the same hifi Pioneer?

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Take a look at the the Pioneer SR-101 (attached) for some ideas. Nice sounding circuit.

So, swapping B+ and B++ on the field coil? I know a lot of radios run the Screens off the first node. No. Both the Plate and Screens, and the feed to the next node come off after the FC. I have attached one example of what I am referring to. At the voltages and outputs you will operate at, there sh...

With only the screen and front end current running through the field coil, not sure if that is enough to generate a sufficient magnetic field. The few examples I have seen run all current through the FC.

I see your power tube dissipation is much more reasonable than that given on the schematic. 13.7V across 130 ohms is 105mA and with a plate voltage of 372V, that is 19.6W per tube! Now that's cooking! Your numbers show 86mA @ 312V; 13.6W per tube. So far, I am not seeing any of your numbers indicati...

The voltages on the schematic are not correct. Case and point, lets assume 4mA on XD for the four 12AX7s. Across a 22K, that is an 88V drop, not the 4V that is shown. So it appears your voltage drop on XD looks OK. Work the math and you may find they are OK.