Building a Bandmaster head having tone control problems.

[StratTone]

I did a Blackface bassman build as my 4th and all is great except the vibrato channel. I did had a Mid Control and wired it like a Super Reverb. What happens is the amp sounds beautiful but you can turn the volume all the way up and if you turn down the treble, middle, and bass there is no sound. I know it is suppose to cut a few dbs but I for sure have something wrong. Any ideas?

[txstrat]

As far as I know if you turn down ALL the tone controls, no signal would get through to the volume control and therefore no sound comes out the amp.

[mac1amps]

Perfectly normal for a Fender tone stack that includes a middle control.

[StratTone]

Wow! I never ever ever ever noticed this on any amps that I own. haha I guess I never had everything on zero to see. I feel like a dumbass and happy about it at the same time. Why doesn't the tone stack with just treble and bass do the same?

[JoeM]

Wow! I never ever ever ever noticed this on any amps that I own. haha I guess I never had everything on zero to see. I feel like a dumbass and happy about it at the same time. Why doesn't the tone stack with just treble and bass do the same?

Because there's a fixed resistor in the place where the middle control is on other Fender models. Usually 6.8k

[loudthud]

In a Fender amp the Mid is wired as a rheostat like the bass pot. When Mid and Bass are at zero and the treble pot is also at zero the output of the tone stack is shorted to ground. Many Marshall amps are wired a little differently where the lower cap goes to the wiper of the Mid control. That way there is always some resistance to ground.