PASTY FACE_Q2_Q3 Mod Switch

[MeC]

Just thought I'd share a slight design change to the Pasty Face. After building the Pasty Face, and finding the gain slightly above unity (built using some Chinese BC109 NPNs (super low hfe 110--matched as required by the circuit design)) the sound, best described as "all fuzzy", I thought through the circuit a little and came up with an interesting mod by inserting a partial bypass between the base of Q2 and Q1 at the Fuzz pot #1 and Vol pot #3 (there is a SPST switch placed at the junction to switch allowing function change: Fuzz/Boost-fuzz).  Additionally, I removed the Tone pot and inserted two 22K fixed resistors bridging 3 to 2, and 1 to 2. Other "mods" were including the 1M R1, jumpering R11 and removing D1 and R12.  The remained of the circuit is based on the Sola circuit.

The goal was to utilize Q3 as a largely "clean" boost, keeping some signal passing through Q2 for a fuzz signal, bypass and "blending" determined by the Fuzz pot and Volume pot.

The result?  Mostly what I expected, but more.  Because there is some inherit lag in the signal passing through Q2 there is a "fuzz bloom", kind of a slight harmonizing behind the "clean boost".  The sound, a bit more like Jimmy's sound on Kashmir.  Of course there is a little switching noise, but my thinking is that I'm going to use one or the other settings and not toggle between the two functions.  I figure that a small value cap between the contacts will likely eliminate the pop.

Anyone try something similar?  Results?  Other mod ideas? Results using other NPN, or higher hfe transistors?  I'm really liking the sound through a single ended EL84 amp. Using the circuit with a PP there's a loss of the fuzzy "harmonizing".

Cheers,
~Mike

[midwayfair]

This is a pretty cool idea. Do you have a way of making a demo?

[Om_Audio]

Ya I am jumping on this thread to reference it when i get to my Pastyface build. Sounds interesting.
C

[MeC]

I'll try to work some demo stuff out.  Between perfunctory guitar skills and using an iPhone to record there will be a lot left to the imagination. 

I might add a couple of notes on the sound of the mod while I figure out some demo stuff. (This might take some time) What I find cool is that it is possible to get the sound of an overheated output transformer, just adding to the Jimmy Page, Keith Richards type sound. Equally, instead of only getting huge sustain from the standard circuit I've found that dialing down the fuzz and turning up the volume it's possible to get a really "clipped" sound. It can get pretty messy and takes a little getting used to playing, and discovering "happy accidents".  It sounds best, to me, playing DADGAD and open G tunings.

~Mike

[Om_Audio]

Oh I love DADGAD! I use a lot of altered tunings. Just finished adding PastyFace to my master BOM today.

C

[jtn191]

this reminds me of some tonebender clones I saw on ebay. They had a switch for "fuzz face" and tonebender. Can't remember the specifics but I think it was taking Q1 in and out