Uproar - Tone circuit mod

[nzCdog]

There's a few threads of Q & A about the Uproar, but this is a simple mod that makes the tone knob much more effective than stock.  I've tried what some suggested by subbing a 100KB for the tone pot and found it changed the whole sound of the pedal.  This is a simple tone mod that I got from Brian Wampler's book that works really well with the stock 10K tone pot in the Uproar.

1. Remove all wires connecting the tone pot to the PCB and instead place a 10K resistor from pads 3 to 1.

2. Run an extra wire from Volume pot lug 2 to Tone pot lug 2...

3. Connect a 47n cap from Tone pot lug 1 to ground... You could use Volume Pot lug 1 or another ground point for this.  

Done!  You can try different Caps, anything 22n or larger will probably do fine.  The result is a more dramatic tone control with the standard 10K pot than before.
Hope it works for you

[bigmufffuzzwizz]

That's an interesting way to set it up. Did you experience volume drop issues with it this configuration?

[nzCdog]

Nope... its just a LPF for the output of the pedal, so its not messing with preamp gain or frequencies etc... I found the stock tone setup acted like a 'notch filter' rather than a treble/presence 'roll-off' in my build... so this is your normal, run-of-the-mill tone knob sound, quite tweak-able with the 10KC pot.

[metfreak]

So if I got this straight, you have to place 10k resistor on PCB pad?

What about other wirings, does it stays the same?

I'm building Uproar as my next build so I'm really considering doing this mod also.

Cheers, Nejc

[nzCdog]

Yes that's correct... disconnect the tone pot from the pcb, and put a 10K resistor on the pcb in it's place.

The tone pot is then connected to the Volume pot instead, acting as a lowpass filter.  You may want to ground the cap to the 3PDT instead for 'proper' star grounding technique.  I just grounded it as described above. Other wiring on the pedal remains the same.

I'll try do a drawing tonight if I can get time, but hopefully the instructions are clear, its just a simple mod.

I would suggest using a 47n-100n Cap (I use 47n, 100n would be a more dramatic tone control)

I also suggest trying a TLC2272 Opamp in IC1, and the stock JRC4580D in IC2
I experimented a bit and really like this comination for a good balance of high end grit and low end 'oomf'

[nzCdog]

Viola!

[metfreak]

Great job, I thougt it was something like that but I rather ask  than mess things up all the way!

Thanks again, very much!