mosfet replacement with digital design

[John Cory]

Hi there digital junkies.
Can anyone out there suggest a digital alternative to rebuilding some old Class B (1980's)mosfet amps. I have HUGE power supplies (68-0-68 Vac) and smoothing (20 000uf per rail).
I would need to get a component list and a PCB design.
I must be honest in that I know very little about digital amplifiers, so, this will also be a learning curve for me.
Would you be kind enough to help with this project?
Regards,
John

 

[Kris0603]

The iron can be upcycled for sure, but if the capacitors are also of 1980's vintage it would probably be a good idea to use fresh caps for a new design.

 

[nigelwright7557]

Class d can be a minefield for beginners.
It is very fussy about pcb layout and decoupling placement.
It took me 3 revisions of pcb before I got one that worked reliably.
Not good but I learned a lot from the exercise.

IR do a project that also includes pcb layout.
Look up IRAUDAMP.

 

[gmarsh]

I'll warn, 68VAC will rectify close to -+100VDC, which is the limit of the IR chipset based amplifiers - I wouldn't risk it. I'd go with a discrete UcD design, it's a good amp and you can change parts to handle the higher voltage.

That or peel some secondary windings off the transformer to get a lower voltage. Or sell it for copper and buy a SMPS.