# Uberdrive Monte Allums GT mod



## vendorofsplendor (Feb 22, 2020)

Hello,

Wondering if anyone here has knowledge what these mods are. Built an Uberdrive for nostalgy reasons, but this thing could use some spice.
Any info would be greatly appreciated.


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## music6000 (Feb 23, 2020)

When you say Spice, Do you mean it's thin sounding, Increase 47nF Input cap to 82 - 100nf.
More Crunch, Change Clipping Diode(s)  ie 1N916,1N916 & 3mm Red LED in D2.


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## Chuck D. Bones (Feb 26, 2020)

C2 and C3 will have a lot more effect on the bottom-end than C1.  SD-1 and TS are pretty much the same pedal, so any of the TS mods are applicable.  More gain: Reduce R7.  Different tone sweep: change C5.  More presence, reduce C4.  Smoother distortion at high gain settings?  Add a 100pF cap across D2.


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## vendorofsplendor (Feb 27, 2020)

My original description was too vague and perhaps not fitting. Finally got to put the box through it's paces in band practice. I'm playing through a plexi-ish master volume amp with reasonably low output humbuckers.
The asymmetric clipping and added mids are the current highlights of this circuit for me. I believe when modded accordingly this one will be able to produce the tones that I am after.
Intended method of usage is to boost clean to slightly overdriven sounds to mild crunch/full-blown chunky rhythms.
I am somewhat able to accomplish this, but with very specific settings dialed in.

With my rig, the pedal is barely usable with the level control around noon and definitely sounds best from 3 o'clock to max (more low ends gets through at higher settings?).
Tone knob does not seem very usable at all. Just kind of have to set it somewhere it does the least "damage" (~11 to 2 o'clock).
Higher gain settings introduces more compression than I would like. Mids starting from 1k (maybe slightly lower) also tend to get "boxy" and "plasticky". Maybe this happens in conjuction with the weird tone control?

This may come across as me disliking the circuit, but that's not the case. I simply think there is much untapped potential here.

Ideally I'd like:

- More usable settings range overall.
- Top-end "bloom" instead of "boxy" mids at higher gain settings.
- Retain original signals low end girth and add slight compression for palm mutes.
- More open overall character.

If something akin to this can be achieved, this thing will make it to the board.
Need to look up on TS mods.

edit. Also open for suggestions about other circuits/pedals to check out.


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## music6000 (Feb 27, 2020)

vendorofsplendor said:


> My original description was too vague and perhaps not fitting. Finally got to put the box through it's paces in band practice. I'm playing through a plexi-ish master volume amp with reasonably low output humbuckers.
> The asymmetric clipping and added mids are the current highlights of this circuit for me. I believe when modded accordingly this one will be able to produce the tones that I am after.
> Intended method of usage is to boost clean to slightly overdriven sounds to mild crunch/full-blown chunky rhythms.
> I am somewhat able to accomplish this, but with very specific settings dialed in.
> ...


Just Remove C6 -10nf & see if the Boxiness  disappears & tone control is more usable.


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## vendorofsplendor (Feb 27, 2020)

music6000 said:


> Just Remove C6 -10nf & see if the Boxiness  disappears & tone control is more usable.



It definitely opened up the highs. Upper range of the tone control might be more usable. Not sure if I am imagining, but there seems to be more input signal mixed in now. 
Already an improvement.


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## music6000 (Feb 27, 2020)

Great!
If you want it to have a bit more Balls, Up C2 to 100nF ( .1uf)


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## vendorofsplendor (Feb 27, 2020)

Did not have a 100nF handy and went with a more subtle 56nf. While I was in there, swapped R5 with a 10k. Friend suggested it, saying that's the only mod on his old SD-1.
Now the low end is better, but still got high passing happening. Need to keep that 56nF in for a while and see how I end up liking it.
R5 at 10k means this thing now boosts already overdriven tones quite a bit better.

Next thing might be to explore some clipping options, maybe by adding a toggle switch.

edit. SD-1 R5 is Uber R6 if I now remember correctly.


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## Chuck D. Bones (Feb 27, 2020)

vendorofsplendor said:


> It definitely opened up the highs. Upper range of the tone control might be more usable. Not sure if I am imagining, but there seems to be more input signal mixed in now.
> Already an improvement.



Changing C6 won't affect the clean bleed, but if taking C6 out causes you to use a lower DRIVE setting, then that does make the clean bleed more pronounced.

Making R5 smaller lets you set the DRIVE lower for more clean bleed.

Try replacing some or all of the diodes with green LEDs.  Start with D1.  Will definitely fatten up the sound.

If you want the TONE control to affect the mids more, make C5 bigger.  If you want it to affect the mids less, make C5 smaller.


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## vendorofsplendor (Feb 28, 2020)

Chuck D. Bones said:


> If you want the TONE control to affect the mids more, make C5 bigger.  If you want it to affect the mids less, make C5 smaller.



Ok will need to try lowering the C5 value a bit.

I figured the issue with the tone control is that it saps the highs when it's turned all the way down. Turning it up to compensate introduces too much mids on anything but a thinner clean tone (unless the gain/drive is set low).


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