JTM50 tone controls

[Brownie]

When all the tone stack is turned fully down, should any signal remain? I mean, is it like the Fender Twin Reverb or 3 knob Super Reverb's tone stack? Is it all shunted to ground? This JTM50 clone has a bass control that doesn't seem to do much, and when the whole stack is turned fully CCW, there is still a signal getting through...

[pdf64]

... when the whole stack is turned fully CCW, there is still a signal getting through...

That's correct.

[SnickSound]

When all the tone stack is turned fully down, should any signal remain? I mean, is it like the Fender Twin Reverb or 3 knob Super Reverb's tone stack? Is it all shunted to ground? This JTM50 clone has a bass control that doesn't seem to do much, and when the whole stack is turned fully CCW, there is still a signal getting through...

Have some fun with this tool: https://www.guitarscience.net/tsc/marshall.htm

Due to the way the mid control is connected on Marshall (not as a variable resistor), you'll always have that 25k resistance under the bass pot which prevents shunting everything. It's normal.

As for the bass control, it's good at cutting bass, but not so good at boosting it. That'd the Plexi way

[pdf64]

It looks like with T and M controls set midway, the bass control should cover a 10dB range at 100Hz.
I find that they're bassy amps, little different to a 5F6A Bassman, setting presence to max helps.

[Brownie]

Thanks for letting me know what to expect! I was afraid there was an error when all pots zeroed didn't shut off all the signal.  What about the tone slope resistor? I chose 33K, but how does 47K or 56K differ?

[pdf64]

What about the tone slope resistor? I chose 33K, but how does 47K or 56K differ?

Right, that's a mod and it's a good idea to mention it.
A JTM uses a 56k slope.
It facilitates a somewhat greater range of control than the 33k used by JMP and subsequent ranges.
Hence your descision to use 33k may be why you're disappointed with the tone controls, bass control anyway.