Starting a Tweed Super/Bandmaster/Pro variant

[Ken Moon]

Well, I'm finally gonna have some time to build another amp in April, so I'm planning to use Doug Hoffman's new lunchbox-size Stout chassis (also sold by Mojotone at a slightly higher price) to build a simple pedal platform, based on the early cathode-biased tweed amps.

I've got a Hammond 291CX PT (325-0-325@207mA), which fits the chassis cutout, and the Mojo769 OT, which has the original 6K primary and 4/8 secondaries, but no 2 ohm secondary, though, so a 3x10 combo is out

I've got a pair of JJ 6L6GBs and a pair of JJ KT77s, along with a whole bunch of JJ 6V6Ss, so I'll try them all. I'll start with a 250R/10W cathode resistor with a 100uF/100V bypass cap.

I have access to a Morgan RCA35 amp to compare, which has the type of sound I'm looking for (but the Morgan has too many switches for my taste. I won't be using the Morgan circuit, though - I'm starting the preamp design with the low gain preamp example in Merlin's book (volume 2).

This time, I'm going to try my hand at a build diary, and provide all calculations and my thoughts/observations as the build progresses.

Of course, any suggestions and opinions are welcomed - that's why I'm here

Wish me luck

[M Fowler]

I use 40-18088 6k/2,4,8 transformer for my Express combo builds.