Adding a tone pot to buff n blend?

[Anthonyj]

I was looking at this pcb for a project idea. Is there a way to interject a low pass filter or just tone pot for the clean signal? So that it will only really mix back in clean bass? Would it be wired directly before the blend jack after c2?

 

[BuddytheReow]

it be wired directly before the blend jack after c2?

yep

 

[Anthonyj]

Should have added this, from what I was reading it should be 10k pot a or b? Going in lug 1, lug 2 is wired to lug 3 then lug 3 goes to a 1nf cap then wired to lug 1 of the blend?

 

[Feral Feline]

I was looking at this pcb for a project idea. Is there a way to interject a low pass filter or just tone pot for the clean signal? So that it will only really mix back in clean bass? Would it be wired directly before the blend jack after c2?

I did that with my first ever build... you can see a scrap of vero for the LPF in the linked pic if you look closely.


From my notes about Tonmann who walked me through how to do it:

BUFF N BLEND MODS: http://www.guitarpcb.com/apps/forums/topics/show/13216660-buff-n-blend-powerful-utility-tool [GPCB FORUM HAS SINCE CHANGED AND THIS LINK IS DEAD]
TONMANN's BnB LPF:
Add an A25K pot paired with a CA 10n / CB 100n combination (see diagram & illustration below) to make the thing a Low Pass Filter

By removing R7 from the circuit board and inserting the circuit above you can add a low pass shelving filter for the clean signal.
The first diagram uses an external pot and the second diagram uses a trim pot with a switch.
At 0% rotation (or with the switch in the ON position for the trim pot version) the frequency response is flat as the pot is rotated high frequencies are cut.

I would suggest keeping the values of the resistor and pot as shown above and socketing the capacitors so that you can tune the circuit as you wish; try dropping CA to 4n7 and then CB to 47n if you don't like the 10n / 100n combination.

Using a small piece of vero board will certainly make construction easy (no cuts and one jumper on each board):

For reference only, 100k not necessarily the real value

Add a lowpass filter
A lot of distortions don't have tone controls. Here is an easy lowpass filter you can add. It will reduce your output a little but if your distortion pedal has lots of gain, this shouldn't be a big problem. If you think about it, this can go right on the lugs of the output volume pot. Use a small trimmer mounted on the lugs of the output pot along with the capacitor.


Variation on lowpass filter

Make the first capacitor one value (for example: .01µF), the second capacitor another (.05µF). Make the pot fairly large ~500K. When the pot is centered, very little tone control is applied. This would go at the end of a circuit or even in the middle of two gain stages.

 

[Anthonyj]

That is awesome, simple and exactly what I was looking for. Thanks.