I got this Carslbro 50 TOP to fix (burnt OT).
OT : Drake 784-213 (4.4k Zaa)
Schematic (thanks Chambonino !)
The point is : on « my » 50 Top, power supply is quite different : PT has a central tap and no bias tap.
On this 50 Top, power supply conforms to the schematic
The 50 Top I have to fix …
So, I retraced its schematic :
I replaced electrolytic capacitors, OT (Hammond 1750N, 3.2k Zaa for JMP50) and 47k bias replaced by a 100k variable resistor
It plays loud with great crunch. Nice vintage amp !