Effects loop with mid boost?

[fuzzmonger]

Howdy,

I've just procured a Fredric Super Unpleasant Companion (companion fuzz and superfuzz in one pedal) and am thinking about putting it in a true-bypass loop with an adjustable mid boost (too get above unity and cut through a band mix a bit better). Just wondering if anyone had a decent mid boost schematic with a variable mid knob. Surprisingly hard to find (well, one without an IC anyway. I'm rather adverse to ICs)

-Fuzzmonger

[Ben N]

Not sure what your objection to ICs is, at least in this application, where the gain is limited and therefore you shouldn't have much, if any, distortion from the IC. The Anderton Frequency booster does what you want. This link is for the core of the circuit. Not that the input should be buffered.
http://www.muzique.com/schem/ca-eq.gif

[GibsonGM]

+1, the Anderton is very useful. 
If you just used passive components, you'd have a very heavy loss of level due to insertion loss.  And things would get MUDDY (crappy sounding).    With Anderton's, you are semi-buffered so as to not load down following circuitry.  IMO, a scheme of this sort is the ONLY way to go for what you're doing....give it a try, easy build, few parts etc.   

[fuzzmonger]

I was thinking of trying something like this

Hopefully that will give me mid boost/cut and treble and bass options. Do you reckon I'll have a volume boost from this circuit or will it just be around unity?

-Fuzzmonger

[fuzzmonger]

Ps, nothing against ICs on any practical level, I just have a transistor fetish ;P

[mistahead]

Just looking - you seem to have the effects loop sorted, from there I recommend you just buffer the input (no IC? KK JFET or BJT buffer off the Beavis awesome site), then put a transperant transistor boost (or LPB) and a tonestack like from Jack's BMP replacements or a James type in.

You now have a mid/low/high/pres/whatever was in your stack active effects without using ICs.

Ultimately you're going to have to do some bandpass cutting to the signal, so boost it up (recovery stage in front of tone, after loop) and put some knobs on it.   

[asatbluesboy]

Ps, nothing against ICs on any practical level, I just have a transistor fetish ;P

I like transistors as they don't need a Vref. They feel simpler.

P.S.: I used the word "feel", as it's a matter of preference.

[mistahead]

Ps, nothing against ICs on any practical level, I just have a transistor fetish ;P

I like transistors as they don't need a Vref. They feel simpler.

P.S.: I used the word "feel", as it's a matter of preference.

I have a LOT more single junction (I liked that term... PRR I think used it the other day) stuff around to play with than opamps, 555's, etc - my preference is what is at hand (like the original guys lol).

[GibsonGM]

I'd suggest something from AMZ for your buffers, rather than using an LPB based thing.  The MOSFET stuff over there is MUCH more transparent to my ear, at least, and still has that "FET mojo".  Designed to do what you are asking, not just stuck in there.  

LPB is great, but is more of a "70s thang' to my ear...more midrangey.  Don't know if it has the kind of in/out Z you want, either.
Just a suggestion!

Check his site, TONS of stuff you'll use all the time there!   http://www.muzique.com/schem/multi.htm
*Link to a BJT buffer - go to his homepage for the FET goodies!*

Another thing....if you get into LT Spice and learn about it, you can "build" these circuits and simulate them, to know what the active stuff is doing to your signal (boost/unity gain, that stuff).  You can plot freq response, and get very close to real-world before you build!  WELL worth the time (not much time) needed to learn how to do this.  And it is free!

[mistahead]

AMZ does have good buffers - and that's where I was trying to point for the tonestack info. The Beavis Audio page has a variety with opamps, FET and BJT schematics if I recall.

The suggestion of LPB for a recovery stage was just nudging at the fact you can colour the tone there too or go transperant.

Nice link - thanks.

[Ben N]

I was thinking of trying something like this

Hopefully that will give me mid boost/cut and treble and bass options. Do you reckon I'll have a volume boost from this circuit or will it just be around unity?

-Fuzzmonger

There's a lot of loss there, with only moderate gain from the jfet. I doubt very much you'll get any useful boost from that without adding a recovery stage.