rodak Messages: 512 Registered: October 2001 Location: Georgia
Senior Member
What are the typical voltage ratings for the tantalum caps found in Kustom (50/100/150/200 series) preamps? I'm going to order a bunch to have on hand. I'm working on my K50-2, and I can see the markings on some of them, but there's something (looks like black spray paint!) on others. I don't see any clues in the schematics, except that the preamps appear to be powered by +/- 8v. the 33uf ones are marked 33-10, which I assume is 10v.
Well the safe answer is to take the preamp power supply voltages and double them so 16 volts for preamp use. They will probably never see that much, but modern caps are much cheaper and smaller than they were in the '60s.
For the power amps, typical maximun voltage will be 40 volts so 45 or 50 volts should be safe.
stevem Messages: 4739 Registered: June 2004 Location: NY
Senior Member
If I might add something else to what Bill has posted it would be regards to any of those amps you posted about and problems in the preamp regulator circuit.
When you have problems in these circuits with bad transistors alot of times the electrolytic caps good bad, this is due to them getting hit with the full 40 volts of the power supply with their own voltage rating being far less.
The number 10 you saw on the cap is more likly to be that caps mfd value, not its voltage rating.
Going higher in voltage rating is not a problem when replacing caps, so it would not hurt to get all 50 volters for the preamp section.