TMB tone stack for TS

[hammerheadmusicman]

So I'm toying with the idea of a heavily modded tubescreamer type circuit with a treble middle bass style tone stack, do any of you have a suitable schematic I can drop in for some testing?

Thanks

George

[oldhousescott]

Check out this thread on the Wampler 65 Black. Note that the tone stack control values have been scaled to better suit the lower impedance of the solid state circuit.

[RobA]

Have you seen this,
http://www.duncanamps.com/tsc/

I've found it to be useful for looking at various tone stacks and fitting them in to circuits.

It's a Windows program, but I run it under Wine and it works fine on Linux or OS X if that's your flavor.

Rob

[jonrhee]

The Glitterrattii already has the bass and treble. You could try incorporating this mid control into the baxandall stack.

[RobA]

If you are looking for a fixed frequency mid in the Bax, it's doable an easier way. I was playing with one for a distortion circuit I was working on. Here's a screen grab of the LTSpice simulation for it. (You should probably ignore the details of my LTSpice work. I'm still learning the proper way to use it.)

I have breadboarded the distortion circuit several times with variations on this tone stack and it does work effectively. I actually prefer the Bax style to anything else. But, that may be because my first good amp was an Ampeg Gemini VI.

[hammerheadmusicman]

Thanks guys, I reckon I'll look into the Bax..

Thanks

George

[RobA]

Just one note on the spice schematic I posted because it isn't very clear, the pots are simulated by two resistors. So, the two resistors in the middle of each tone control with the output line coming out of them correspond to one pot each. The pots are linear pots on the active Bax, unlike the log pots on the passive James version.

Is there a better way to do this in LT Spice? It seems silly to do it this way, but I didn't see an actual pot in the parts available.

[hammerheadmusicman]

Thanks for pointing that out, i haven't ahd chance to have a look at this yet, myself and a fellow gear head, have just spent about two hours trying 12 different dual op amps and cataloging the results.. a blind test is in order! Next Diodes. Then try the tonestack!

thanks

George

[RobA]

Blind op amp tests are kinda fun. I've tortured my family with them multiple times.

[RobA]

Oh, I should mention that in that actual Bax tone stack, an OPA2134 works really well if you are doing a split supply. If you are doing single supply, there are better.

[hammerheadmusicman]

OPA2134 was one that got a * next to it meaning it's in the running, sounds awesome! `what would would you say are the 'better ones' you spoke of? Just out of interest.

George

[RobA]

I remember the NJM/JRC2082D as being pretty good. But the two that I liked best in the single supply configuration where the TLC272/TLC277 and the TLC2272. Although, the TLC2272 has a lower max supply voltage.