Originally posted by czech-one-2
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You may be asking why build a single ended musicmaster bass amp? Well,I have all the parts from two DOA amps and it should be a relatively simple build and kind of unique!
Unique? ... sure !!!
Will it work? .... mmmmhhhh .... no.
However, I'm stumped with the champ 12 Power Transformer. Its a Schumaker I believe and has the usual two red,2 green and a yellow 240 volt tap [I'm in the EU]. It has a grey wire that went to the on/off switch on the champ 12 and a black wire that went from the fuse to the on/off switch next to the grey wire. It also has a blue and brown that are wire nutted together and an orange that is cut and was wire nutted.
Then youŽll have a certain +V (whatever the Champ used) and 6.3V filament voltage, suitable for one 6L6 and two 12AX7.
You can build any Bass amplifier which is happy with tat tube complement.
In fact, the Champ 12 as-is is a good Bass amp ... not too different from a Blackface Bassman, where the "good" channel was the "normal" one, the so called "Bass" one being muddy.
You just need a Bass speaker in a closed or tuned box of suitable volume instead of a shoebox sized open back one, which is fine for guitar
My problem is that there is a red and yellow PT wire on the musicmaster bass amp layout that goes to the 220ohm cathode resistor. The Champ 12 PT does not have this wire color code so I'm at a stand still. [See attached Musicmaster Bass layout]
Just rebuild the Champ 12 Power Amp and supply, and add whatever preamp you fancy ... even an Ampeg type one.
12 PT wires can be used for this cathode resistor location, specifically one of the un-used wire nutted blue,brown or orange wires.
I know this might be a lame question, but this is my first build and its the only thing stumping me!
[If this helps, the black PT wire shows continuity with the blue and brown wire nutted wires]
I know this might be a lame question, but this is my first build and its the only thing stumping me!
[If this helps, the black PT wire shows continuity with the blue and brown wire nutted wires]
And please post schematics, raw layouts are incomplete and create more questions than they answer.
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