Tonefiend Forum

I just read this in a post on FB from God Box Effects.... see here for the post and schematic: https://www.facebook.com/photo.php?fbid=478121342243112&set=a.315895688465679.77637.170243319697584&type=1

The reason that Fuzz pedals seem to like single coil pickups is due to the biasing of Q1. The biasing resistor sets the impedance of the transistor. The impedance determines how much of the guitar signal is transferred. Most SS hover between 5-15k ohms. Thusly the transfer is between 1-2 to 1. A relatively accurate translation. BUT, 'buckers hover around 25-55kohms, which means that considerable HF is lost. In a fuzz, this isn't a huge concern, as they are rather bright. One work around is to bias Q1 higher. You will sometimes see ranges in the 50k-100kohm. At this point, you overcome the impedance issue, but now have to be more careful about transistor selection and sorting. Catch 22. You'll notice two 50pf caps. Those are for RF and noise control. RF and noise filters generally perform better when used in sets/pairs, vs one component to do it. ie; two 50pf ceramic HF bleed caps at two different locations will perform better than one 100pf cap. As an added bonus, it keeps the fuzz from gating abruptly as the signal voltage drops, allowing for a nice even decay and very little sputtering as the notes fade. The JIMI JR is patterned after the 'OLD SCHOOL' Arbiter FF. It's relatively high gain and very very quiet.

I'm sure this is obvious to you engineering types (or wrong if you happen to know otherwise), but I've had this nagging question in the back of my mind for awhile as to whether some pedals could be customized to better match the particular guitar/pickups that you play into them.

So, my notion is then whether it would be advantageous on some pedals to have a switch that swaps that early part of the chain to attenuate between lo/hi output. While this will certainly show my blatant ignorance, I think a buffer essentially compensates for some of that, but since certain pedals don't play nice after a buffer, designing them with some variable attenuation should allow you place them wherever you want and 'maximize' the effect with respect to the rest of your chain.

Overkill? Talking out of my A? (at least one of those is a yes)

hmm. good point. I remember that post, but I didn't quite get the connection at the time. One of the projects on my to-do list is to build a 'front-of-chain' box that will send a variable V+ over the other side of a stereo cable to let me experiment with more robust onboard effects. I thought I'd put a switchable buffer on there. Perhaps I should also add a switch or rotary step dial with a couple different resistors for changing the impedance.

Are there any other tweaks that would be cool to add to a sort of first-stage pedal?