DIY Class A/B Amp The "Wolverine" build thread

[danieljw]

Some progress yesterday. I configured the DIYaudio soft start, 2x Antek transformers (stacked on top of each other), and 2x DIYaudio PSU (also stacked on top of each other) with the success for end result of +/- 71.5VDC! I haven't figured out why the -71.5VDC side of each PSU won't light the LED, maybe I installed it backwards? I can't wait for the new boards to be delivered!
View attachment 1480050

Check your led polarity on the side which didn't light up, that would be my guess.
Make sure the power lead is disconnected and the caps are completely discharged first.

Take your time to get the psu 100% and stay safe !

 

[Mainframe]

I am going to have to mull this over. Question: is there any point in shielded toroids if I have an entirely external PSU section?

You'd think the external chassis would provide the shielding, but not completely in my experience, I've had vintage pre/power combos that would hum like crazy through the speakers if the preamplifier is on top of the power amp. Lift the preamp amp and the hum would get audibly quieter the further it got from the power amp. Mind you, that was a poor 1200VA E-I transformer in the power amp that had a hard 40 years with no soft start and had some mechanical hum anyway.

I think it's primarily down to the winding+core quality, followed by potting. I've got a relatively cheaper Toroidy Audio grade coming for my EF3-5 so will be interesting to compare with the Supreme Audio grade I have here already.

 

[mbrennwa]

For safety reasons you'll want everything in one chassis, with a single mains earth.
Dual chassis means detachable earth cable, which is no good.

 

[danieljw]

This is a good point about the earth conductor.