Hi All
I picked up a 68 bassman head and am going to hot rod it up. Someone(before I got it) hacked the chassis and put in two extra power tubes, hacked
the power trans location to accept a 100 watt (Mesa) PT. The output trans is also a Mesa 100 watt.
I want to revert to two power tubes and use tube rectification. Also, I want to go adjustable bias. The PT I’m using doesn’t have the 50v tap for biasing. I’ll use a 250 ohm 10 watt and 25u/50v.
The rest of the amp is a bassman. New filter caps and electrolytics on the board,
choke.
The hot rod part is utilizing the half 12AX7 that isn’t used on these amps. Putting a gain pot at the low input jack location on the normal side. Also a switchable cathode from normal to .68cap/2.7k ohm on that half the tube.
The output trans I’m using is possibly a lower watt(don’t know how to check that).
I picked up a 68 bassman head and am going to hot rod it up. Someone(before I got it) hacked the chassis and put in two extra power tubes, hacked
the power trans location to accept a 100 watt (Mesa) PT. The output trans is also a Mesa 100 watt.
I want to revert to two power tubes and use tube rectification. Also, I want to go adjustable bias. The PT I’m using doesn’t have the 50v tap for biasing. I’ll use a 250 ohm 10 watt and 25u/50v.
The rest of the amp is a bassman. New filter caps and electrolytics on the board,
choke.
The hot rod part is utilizing the half 12AX7 that isn’t used on these amps. Putting a gain pot at the low input jack location on the normal side. Also a switchable cathode from normal to .68cap/2.7k ohm on that half the tube.
The output trans I’m using is possibly a lower watt(don’t know how to check that).