Hi there. I got this KUSTOM III head from 1974. It's dead for already two years and I started repairing it last week.
One of the preamp supply voltage zeners was broken so I replaced both of them. (+38 Volts appeared on all pre-amp circuitry instead of the normal 12 Volts.)
During that work the bridge rectifier broke so I replaced that one also. The amp brings out some sound now if I wire channel one output directly to power amp in but definitely no 130 watts.
On the channel two preamp board there is an IC called SL22211. It is use to mix and buffer the ch1 and ch2 signals I think, and I think that one is dead also. Is this a two channel opamp? Anybody got schematics of this amp?
Bill Messages: 64 Registered: March 2002 Location: Kansas
Member
Broadway Music has schematics for this amp, but doesn't show individual parts on boards for the most part. I think they want three bucks a pop.
Thrill Bill
Bill Messages: 64 Registered: March 2002 Location: Kansas
Member
Yep, here is the link to the site. Then go down to the link for Kustom Schematics.
http://www.broadwaymusicco.com/kustom1.htm
Lots of nice historic info on the site as well.
Good Luck
Thrill Bill
NTE replaces that IC with the following:
Industry Number : SL22211
NTE Device Number: NTE725
IC-DUAL LO-NOISE OP-AMP,14-PIN DIP
Mouser sells the chip for $8.09.
www.mouser.com