Treble Cut for Multi Face (Diagram Included)

[amonte]

I've built a Multi Face based on the old Home Wrecker article - it works great, but I'm trying to add some additional tone shaping options.  One of the things I added was Joe Gagan's input cap blend, to add a "Bass" control to the pedal. 

I liked the overall sound of the Multi Face, but in general, I find FF pedals to be a little too bright for my liking.  My goal was to add a similar cap blend on the collector resistor of the second transistor in the circuit.  I thought I had it worked out correctly, but turning the tone knob doesn't seem to result in any change to the sound.

Before I had lugs one and two wired together and connected to the junction of transistor 2's collector and the 10K resistor (as shown), my original attempt had lug 1 connected to one cap, lug 3 connected to the second cap and lug 2 connected to the junction of transistor 2's collector and the 10K resistor.  With this configuration, I got the first cap engaged when the pot was rotated fully couter-clockwise and the second cap engaged when the pot was rotated fully clockwise - but inbetween, it sounded as if neither cap was in the circuit - there was a noticeable jump in brightness and hiss.



Can anyone give me some guidance?  I'm sure I'm likely missing something obvious.  In a real pinch, I might lose the pot and wire up a switch to engage either of the treble cut caps.

[amonte]

Would a low pass filter after the output cap be a better way to do this? 

[amonte]

I just found this -

http://www.diystompboxes.com/smfforum/index.php?topic=61730.0



It's meant as more of an input cap blend, but I can't see why something like this wouldn't work with the +/- going to either sides of the 10K resistor on the collector of Q2.