Hi Dan,
First of all i would like you to thank for your wonderful job and passing the same to DIY community.
My First Question is
In your article you have mentioned "Various measurements of the amplifier on an oscilloscope are shown in the photographs below. The amplifier is down -3dB at 208kHz and can deliver 58W at full power"
Is it 58 Watts of class A output for single Channel?
My Second question
Why there is need of such a huge Power Supply. If i am using 8200uf Caps x 10 Nos for Each Channel what will be the Problem?
Further i would like to inform you that I have had already made the PCB as per your schematic (using equivalent transistors, the transistors i am using are KSA992, KSC1845, KSA940 & KSC2073), The PCB is tested, I had to change the 47K resistors to 22K to set the Bias to 1.5 Amp, I am measuring around 480 to 500 mV across the 0.33 ohms resistors. I had tested the PCB for about 3 Hours today everything is fine, Even at output the DC offset is around 5 to 15 mV which keeps on changing. There is a slight humm noise in speakers which can be heared only when the ears are at distance of 5 to 6 inches from speakers. The testing was done with 250 va transformer, the output Voltage I measured was 31-0-31 Volts DC for single channel with Power Bank having 8200 uf x 10 Nos Capacitors. The Sound was very sweet and till date this was the Best amplifier i have ever heard. And i am very happy with the Sonic results.
I would also like to mention in detail about the Bias, When i started the Testing the voltage across the 0.33 ohm resistor was about 375 to 380mv after 10 Minutes it went upto 500 mv and was increasing, then i powered on the Ceiling Fan and the Bias again came down to 470 to 480 mV which was stable during my 3 Hour run. Second thing is i measure different voltage across both the resistors, the Voltage difference is about 15 mV. is it OK?
Below is the Photo of my PCB layout, In this layout i have made provisions to use the equivalent transistors with different pin layout also.

Below Photo is of PCB testing. the Heat sink is Horizontally placed on Ground but i turned it to Vertical during testing.

There are also few more question for which I may bother you later. Once again thank you for your wonderful job.
Regards,
Sadik Bhatkar
India