Fuzz face with rotary tone/frequency selector?

[Lord sonic]

Hi People
A friend has asked if i could make a fuzz face for him with an added rotary tone/freq selector. I haven't had much experience using these switches, but have made loads of other fuzzes and overdrives from the guitar fx site. Could someone point me in the right direction, or offer suggestions for something on vero from the site that would give me some ideas? Cheers in advance! pete

[nocentelli]

You are describing the Seymour Duncan Tweak fuzz: Simply a stock silicon fuzzface with a rotary switch that selects different values for the input cap. This is the kind of switch you need:

http://p.globalsources.com/IMAGES/PDT/B1023007533/Rotary-Switch.jpg

It's a 12PST, so the guitar input would go to the common pin in the middle, and each of the outer lugs would lead to one end of a different value cap, maybe a range from 10n up to 2u2. The other ends of each cap need to be connected together and connected to the Q1 base. Most rotary switches have a ring with a tab inside that can be rotated to set the number of positions on the switch so you don't have to use all twelve.

[Lord sonic]

Hi nocentelli,
thanks very much for the info. Yeah think you are right about the switch looks right! The pedal he's after me cloning though is one of these http://www.dirtyboypedals.com/#!afro-fuzz/c9zr
which is a germ/si fuzz face? When you say the cap leads need to be connected, how exactly do you mean? Do you mean twist all the ends together and then solder a lead to q1 transistor base? You probably don't mean that, but I am just trying to visualise! Are there any vero board layouts out there that would show this type of a set-up? Thanks again for your help, Pete.

[Beaker]

That's exactly what Nocentelli means. I know this is for a totally unrelated circuit (it's a guitar varitone circuit), but this image shows precisely what you are visualising.

[Lord sonic]

Wow guys, thanks for the help! So I could try the easy face, which uses silicon and germanium transistors and then maybe add a tone selector? That picture explains it really well for me, thanks again guys!

[nocentelli]

The Black Arts Black Forest is a Colorsound Overdrive/Powerboost but with the same type of input cap selector you're looking for, and the layout here at tagboardfx uses a separate daughterboard to secure all of the different caps. Notice that the guitar input is connected to one side of all of the caps in parallel, and the switch selects which single cap output goes to the first transistor. This will work in exactly the same way as the method i outlined above -

http://tagboardeffects.blogspot.co.uk/2014/04/black-arts-toneworks-black-forest.html?m=1

[Beaker]

Thanks Nocentelli - I remembered that there was a variable capacitor rotary switch daughterboard arrangement on here somewhere, but I could not remember which circuit it was.

[Lord sonic]

Thanks again guys!

[Lord sonic]

Hi Guys have decided on this si/ger fuzz face and it sounds good. would like to incorporate the cap selector switch as you had suggested via the black arts black forest vero. this is the circuit.
http://tagboardeffects.blogspot.co.uk/2013/04/creepy-fingers-effects-si-fuzz-face.html
do i need to change the positions of the switch A and input? do they still need to go to transistor base? Getting a bit confused, could do with enlightening! Cheers in advance.

[Ciaran Haslett]

Yip...remove the Input wire and the 2u2 cap from the board.  Make up the cap daughter board with your desired cap values.  Wire your foot switch Input to the cap board as shown and wire the common pole on the rotary switch to 2 rows below where the Input wire was.

[Lord sonic]

Hey thanks Ciaran! Will give that a go, Cheers!

[Lord sonic]

Hi Guys!
just a quick update and question. So i managed to make the creepy fingers fuzz face, but with si & germ transistors, with a tone/cap selector as you guys advised. It works great, I used a npn ac176 with a bc108c. the only problem seems to be a lack of volume, have to really whack it on full to get past unity gain. The vol pot is a 500k log, would it increase volume to change this value, or is there another way? the fuzz pot is 1k reverse, which i didnt have so just used a normal one. As ever any suggestions really appreciated, thanks!

[nocentelli]

You can increase the (330 ohm) +9v to output cap resistor to get more volume, but you should reduce the 8k2 to keep.the bias point the same, i.e. If you up the 330r to 1k you should probably reduce the 8k2 to 7k5.

[Ciaran Haslett]

You could raise the 330r while at the same time lowering the 8k2 to keep the total resistance between them at 8k5ish.  Apparently this will give you more volume at the expense of fuzz.  But if you like the fuzz as it sounds now, I'd just tack an LPB-1 on the end and make that your new volume pot.  I.E.  Gtr > FF > LPB-1 > Amp

[Ciaran Haslett]

Nocentelli beat me to it

[Lord sonic]

sorry for late response. Gonna give that a go. in the mean time have made a 'drag n fly' another si/germ variant, with an OC140 sounds good and loud! so if it dosent work out with the volume on the other one he could always have the drag n fly. Thanks again, couldnt have done it without yous!