ADHD sounds dark

[eh là bas ma]

Hello,

I am not sure if there is even an issue with this build. I notice it sounds much darker than the other overdrive and distorsion I built before.

Everything sounds fine with the distorsion. Switches are effective, with a noticeable mid boost.

When the tone knob is fully CW, it feels like it is really at midrange, not much high frequencies audible. Going CCW it acts like a treble cut.

I checked the pots values, the soldering, the caps values, nothing obviously wrong there.

I think I might have made a mistake with a resistor value somewhere.
Or maybe the 22n capacitors are the wrong type ?

https://docs.pedalpcb.com/project/ADHD.pdf

Any help would be welcome !

Here is a picture in case someone can spot something I missed :

 

[music6000]

Hello,

I am not sure if there is even an issue with this build. I notice it sounds much darker than the other overdrive and distorsion I built before.

Everything sounds fine with the distorsion. Switches are effective, with a noticeable mid boost.

When the tone knob is fully CW, it feels like it is really at midrange, not much high frequencies audible. Going CCW it acts like a treble cut.

I checked the pots values, the soldering, the caps values, nothing obviously wrong there.

I think I might have made a mistake with a resistor value somewhere.
Or maybe the 22n capacitors are the wrong type ?

https://docs.pedalpcb.com/project/ADHD.pdf

Any help would be welcome !

Here is a picture in case someone can spot something I missed :

Try this to see if your resistors are OK, Click on Bands for 5 colours:

Resistor Calculator

Resistor Calculator is an App developed by CherryJourney to help the user find the value of a resistor.

resistor.cherryjourney.pt

 

[eh là bas ma]

Thanks, all resistors are checked, it looks ok.

I will try to swap these 22n, C1, C8, C13 with film caps...

Edit : I checked and they already are film caps...

I am starting to think that there is nothing wrong on my build, the circuit is calibrated this way :

"If you built the ADHD board according to the build doc it will be a little darker sounding than the original OCD, but the difference (At least from the one I built) wasn’t significant at all" (pedalpcb forum).

Well, it is a bit more significant on mine.

What could be the simplest way to get more treble in this circuit ?

 

[Wizardofwoz66]

The easiest thing to do would be replace C8 with a larger value (will send lower frequencies to ground). You can also remove and jumper R14 (this will drop the overall resistance to ground, would probably give a slightly more usable range on the tone pot. You can also try both of these things in combination, maybe switch C8 for a 10 nf or 4n7 cap and jumper the resistor.

 

[Wizardofwoz66]

The tone control is a little strange on this - it's not a traditional high pass or low pass filter. It might be worth socketing the cap and resistor and playing around. The actual easiest thing, now that I look at it, is probably to swap in a smaller cap for C9.

Another option is to put a jumper from the output side of C8 to lug 3 of the volume pot like this:

This is how a typical high pass filter would be formed