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Top of my head, bottom of my heart......

Posted by drlowmu on June 20, 2012 at 07:47:59:

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Hi Amateur,
Quick analysis and comment. The supply you posted is neither fast or optimal. High HYs and high Cs are NOT your friends. Use as little as possible to get the job done.
In Push Pull, you can have 2 VAC of ripple to the Finals and it will not be a problem.
I have simulated your supply, guessing at the DCR of the 300 mA. rated power transformer. It is pretty poor at a 15% current step test. It settles in about 550 mS., and has a dynamic Z of (12 volts drop divided by 31.2 mA. current change, or,) 384 Ohms.
My suggestion has under 1 VAC of ripple, inaudible to the Finals in P-P, and it settles in 30 mS (18 times faster) and drops only 3.8 VDC on a similar 15% current step. The Dynamic Z is (3.8 VDC drop divided by 15.75 mA. current change, or,) about 241 Ohms.
Your supply uses two expensive 5AR4 cathode type rectifiers, my suggestion is to use two less expensive readily available 5U4GBs. Such a tube rectifier has NO cathode, and it sounds good. Buy a good Hammond 300 series (highest possible current rating) transformer, a shared L1, which can do 2 A. of current, and a "Y" arrangement of two inexpensive EDCOR 2 HY 21 Ohms open frame chokes, one for each channel.
I have drastically reduced the DCR, HYs, and uFs in the supply.
What I suggested, what I would term a "modern " power supply will ROCK on playing music and it will be worthy. The amp will now kick butt.
I have only quickly considered the supply to the finals, I would use a R/C to the front end, and those values can be easily be determined in PSUD, shoot for 1 or 2 mVAC of ripple.
This is just my initial idea, I know it will play well, and I avoid L-Critical supplies, unlike many others here.
Jeff Medwin