Blending clean and fuzz signals...

[plexiphile]

I've been fooling around with a Bazz Fuss circuit (with a 100k pot for volume output) and want to blend the clean input signal with the fuzzed output signal.  If I place a jumper from the board input to a, say, 500K pot (as this is what is used inside my guitar) and then to the output jack, shouldn't the clean signal be running in parallel with the fuzz signal? I should therefore be able to blend the two signals, right? It doesn't seem to work that way for me.  Am I making some obvious dumb mistake?

Thanks!!!

[fatfoohy]

you would probably just want to use a 100k or 50k as to minimalize your loss, but this will still make your signal fairly quiet, and more than likely, below unity gain, the way i would do it would be to use the buff n blend

[Derringer]

You should definitely use a buffer (the buff'n'blend is a buffer with two outputs) to split your incoming signal into two equal signals
however, you're going to run into a phase issue for this particular application

assuming that you're using the single transistor Bazz Fuzz design, the phase of the Bazz Fuzz output will be 180 degrees from the clean signal, so when they get blended together it'll sound a little nasally. You may like that sound or you may not.

To counter it, you could still use the buff'n'blend and then put a single transistor gain stage (set for gain of 1 or maybe a little more) on the clean-non-bazz-fuzz output of the buffer and that would flip the phase to match the bazz fuzz.

If you're comfortable working with opamps, you could take a dual opamp, set up the first amp as a buffer and split your signals, run one signal through the bazz fuzz and then use the second amp as an inverting buffer to flip the clean signal to match.

[B Tremblay]

The Splitter-Blend will do the trick and can handle the phase matching:
http://runoffgroove.com/splitter-blend.html

[birt]

it will also sound better if the "clean" has some overdrive. christal clean and fuzz mixed never sounds good to me

[plexiphile]

Wow...thanks for all of the replies.  There looks to be a bunch of great info here. Still wondering...If I were to put a 'gain' control somewhere in there would I not get a similar result? Would that be placed directly after the emitter?

I'll keep playing around tonight.  I can't wait to get soldering!

Have a great weekend, all.
Jeff

[Earthscum]

Just wondering, which version of BF are you using? Actually, what are your parts... easier and quicker to reply with, lol... such a simple circuit.

Basically, I did a similar thing as what you are trying to do, but I built 2 BF's and ran them parallel to each other. Basically, you put the same inputs in, use a 100k Lin pot with the legs attached to each output, and then a 100kA volume pot.

This is where I am asking which parts you used. If you just went emitter to ground, then you have your distortion circuit. If you built it with a 1k pot and cap to ground, then you may have your clean blend channel. What I found worked good (I may go revisit some BF's tonight) is one channel with 2N3906's in Darlington config with a 10k to positive, a 1k pot with 10u cap to ground (gain), and a pair of Si serial diodes in feedback, rather than 1. That was replicated on the second circuit, and then I could adjust one for clean or slightly gritty (seemed to mix better), and set the second gain to something that would mix well. It has some sweet interactions, for sure. This also keeps buffering out of the otherwise simple circuit.

I love the BF. If all else fails, I can build a BF really quick and start probing for signals... it has such a distinctive sound to it, and carries so many harmonics that it's a decent circuit to tune filters with. It has so much gain that I use it when I can't tell if the boost stage I made had enough gain. Just pop out your biasing resistors and drop an LED across the feedback. If you got no signal at output, you can probe for it easier across the circuit than a dry signal.

[Earthscum]

So, I just tried something interesting... I used a BF clean stage, then made a buzz box to re-invert the signal and basically made a push-pull output stage. Try it out, kinda kewl, but you can't get all the way clean.

[plexiphile]

@Earthscum...
    I'm using the Homewrecker schemo...2N5088, 4.7uf, 100K, .1uf, 1N914.  I'm going to try the emitter-to-1k pot trick. What value cap would you recommend? Thanks for the killer tips...funny how I'm always gravitating toward the simple fixes. Maybe that's why I'm obsessed with the  Bazz Fuss...I've made and gifted probably 10 now.

Jeff

[dmc777]

I'm still interested in how you would add a blend pot in a pedal that would allow you to go to completely try to completely wet. Kinda like Barber Tone Press. Also, DMB pedal's have been adding a blend control into their pedals. This is a concept I've always wanted to know. I have a RI Deluxe Electric Mistress and would like to add a blend or level pot to it. Have the schematic. On the schematic there's a trim for "mix" but it doesn't really work like it should.