UK Vintage Radio Repair and Restoration Discussion Forum - View Single Post - Another DC coupled amp (Ampeg bass combo)

ITAM805 · 13th Jan 2018, 1:05 pm

Sortedradio, Michael, yes we must presume it was factory fitted

The poor zener diode D12, would have been sinking the full negative rail, 39V in this model, and some how held up at least for a while. The owner said it never worked right (!) and stored it for a couple of years before digging it out and giving it to me.

So 2 new zeners and a 330R 10W are on order and hopefully it'll be a fix...

13th Jan 2018, 1:05 pm	#16
ITAM805 Nonode Join Date: Jul 2010 Location: Folkestone, Kent, UK. Posts: 2,172	Re: Another DC coupled amp Sortedradio, Michael, yes we must presume it was factory fitted The poor zener diode D12, would have been sinking the full negative rail, 39V in this model, and some how held up at least for a while. The owner said it never worked right (!) and stored it for a couple of years before digging it out and giving it to me. So 2 new zeners and a 330R 10W are on order and hopefully it'll be a fix...