VintageKustom.com: Repairing Kustom Amps » K200-B5 reverb questions

Re: K200-B5 reverb questions [message #26245 is a reply to message #26236]

Sun, 30 July 2017 20:08

terminal
Messages: 20
Registered: June 2009
Location: GEORGIA

Junior Member

update: I grounded the return rca input, and found the switching all works as it should. With the input grounded, the wolves howling is gone, but there is a lot more 120Hz buzz compared to the clean channel. (that is to say, with the reverb input grounded I can A/B the two circuits and compare clean to clean). I studied the reverb board schematic looking for an electrolytic that might be a power supply filter cap. The only one I saw was C804, so I replaced it but that made no difference... looking at the entire circuit, I think I should have examined C713 & C317 on the power amp board...

As for the howl, I think I'll buy a replacement tank. My tank is suspect.

When they swapped out 90% of the resistors on this board, they also did the same thing to the power-amp board, but --get this-- the 4 preamp boards still have all their original carbon comp resistors!? If they did all this work for noise, you'd think they'd swap out a preamp channel resistors as well., so who knows what and how this happened.

They also replaced the 1N3754 with a FES16JT 1317A mounted to the power transistor plate. Lots of work done on this amp.

Report message to a moderator