Another FF question - slow phaser-like pulsing

[captntasty]

Well, I'm back to fiddling with the FF(GGG positive ground - http://www.generalguitargadgets.com/diagrams/fuzzface_lo_pp.gif) and noticed this slow phaser-like pulsing, not swooshy, more like a P45.  At first, I thought I was hearing things.  Bias is correct  - 4.5v-5v - and it generally sounds good, sounds like a FF. 

The mods I have done are nothing too extreme - one of the Fuller mods "1K linear pot in series with the 470 ohm resistor in the collector circuit of the second transistor, still taking the output from the top end of the 8.2 K resistor" a la Technology of the FF, RG Keen - which acts as a bias fine tuner on the exterior of the pedal - and subbed a 500K trimmer for the 100K resistor (R3) and a 25k trimmer for the 8k2 resistor (R5) to help in setting the bias with varying trannys.

I recorded a sample into Wavelab and scrolled through the visual waveform representation(simulating an oscilloscope) in what would be like 1/2 or 1/4 time, and sure enough noticed this rythmic ripple or wave that slowly but surely rolls across the waveform.

Any ideas what causes this?  It does it regardless of trannys in the circuit... could it be the two trimmers on the board interacting to create, well something - I guess I don't have the vocabulary to clearly explain it.  Any help and advice is much appreciated.

[markm]

Motorboating maybe?
I think unfiltered power supply is one of the causes of motorboating as well as mis biased trannies....
Maybe even pinout could be an issue.

[ildar]

Fuzzes are notorious for oscillation. Do a search for some possible causes/solutions.

[captntasty]

This isn't the normal crazy oscillation or hum or any other type of "noise" - fixed that by going to + grnd.  This is really subtle and really slow - now that I think of it, I could get the same thing from my EA Trem with a very slow speed and depth control set for barely any effect - just a slight pulsing of the volume level, barely noticeable.   I'm using only battery power...

Perhaps some things are meant to be a mystery... if I ever find out the cause it would be great to harness and control it - FuzzFace and Trem in one pedal!