Fulltone Ultimate Octave

[Derringer]

since it's already been resurrected, when ya'll say "scoop cap", which cap are you referring to? I'm confused... modded my FTM clone to UO specs per El Heisenberg's posts, but now I notice they were posted before this thread came about. I haven't been thrilled with my clone either, it's very BMP and not quite QOTSA, even with UO mods.

C3 on the schematic a few posts above
make that 0.015 uf and you'll leave that BMP sound in the dust

and while I'm here ...
I added a 10K resi stor in series to the input and also wired the sustain pot as a 100K variable resistor. To my ears it gives more "texture" to the fuzz. It's throatier which I prefer.
Thanks for those suggestions Liquids

I also have rigged up the octave switch so that when in fuzz mode, the diode (D5 on that schem) is bypassed. I don't like it this way and will try bypassing this diode with another germ. diode in the opposite direction. And if I ain't happy .. back to stock switching it goes because I like that sound better so far.

[jpiddy118]

Thanks! Funny how the mod went from .047uf up to 0.1uf, now down to .015uf... curious to compare the differences

[jpiddy118]

HUGE difference in the octave sound... love it! but now i'm not crazy about the overall fuzz. Maybe there's just no pleasing me 

I have a .01uF in the tone stack (C1/2 in above schem, c10 in GGG, no toggle, just permanent 'fat' mode). Maybe both of these in the tone stack are too much now?

[jpiddy118]

FYI, found a .022uF in the "scoop cap" spot works best for me with the "fat mode" .01uF cap... best of both worlds for fuzz and octave with a Les Paul and ballsy clean amp copping some Qotsa riffs. Tried just about every possible combo i had in stock, including all original FTM values, UO mods, and in between.

[Mark Hammer]

Dumb question, maybe, but since I've never played one, just what exactly IS the sonic difference between this Fulltone pedal and any other Tone Machine clone?  That's not a snipe, I just don't know that much about it to know whether there are some design choices that produce different sounds, more consistent sounds, or whatnot.

Somebody enlighten me.

[Derringer]

I think it's more just Josh Homme mojo-factor than anything else. Which I as well totally bought into when I first wired up mine.
It seems that the only changes really are just cap choices.

[zstalin]

Hey guys,

Sorry for the necro post! I just got a Fulltone UO at a pawn shop for dirt cheap. I have a buddy who could mod it, but I have terrrrrrrrrrrrible eyesight. I've been poring over this thread and the popped open pedal to find this "scoop cap".

Could anyone offer any advice? If I take a picture maybe someone could help? Right now the pedals is just too midrangey. I'm using it with a Les Paul with PAFs into a cleanish loud (not deafening) Marshall and it's just a bit too much. I was hoping I could experiment with the values like jpiddy and see what I could do that would sound best for live use.

Thanks to everybody for all the contributions and leg work. I can go get these mods done from a pro, I guess, but I thought I might be able to do it for free with a bit of guidance.

Can anyone explain what the scoop cap mod does? e.g. how does the .015 sound vs the .1 later fulltone vs the foxx? I can of course try them all myself, but was just curious. I have a few spare electronic parts I'd be happy to give away for any help, although it's not much, as a gesture of good will.

Cheers,
Brandon

[duck_arse]

post the pics, it'll give us something to look at. someone will probably find the caps, too.

[zstalin]

Thanks DA. Right now I only have my potato of a cell phone, but I will upload a clean gutshot asap. The phone pictures were illegible between all the tiny resistors and the greeny caps/green circuit board.

[tchock]

Sorry to revive an old topic but I'm willing to build myself the Ultimate Octave as well.
Could anyone send me the schematic, please? andrediasrosa@gmail.com
Some pictures would help, also.
Thanks!

[stonerbox]

Sorry to revive an old topic but I'm willing to build myself the Ultimate Octave as well.
Could anyone send me the schematic, please? andrediasrosa@gmail.com
Some pictures would help, also.
Thanks!

Here's a good start.

[tchock]

Thanks! Only last week I had the time to build this and it's working fine EXCEPT for the octave part. The octave switch does nothing, there's no octave at all!
I've been troubleshooting for a week now without success. Tried changing capacitors, transistors and diodes, tested everything seems to be working fine but... no octave for me. 
Any ideas where else should I look at, please?

[PRR]

> Any ideas where else should I look at, please?

DEBUGGING thread, top of this section.

> there's no octave at all!

Voltages around T2 may be most useful.

[Maciek17]

Hello guys.

I know "Golden Shovel Award" goes to me, but this is the best topic where I found solutions which I need. I'm very grateful for your experiences, especially for El Heisenberg.

I decided to build a Fulltone UO to get that iconic Josh Homme's sound with my semi-hollows. Fat, wide midrange, creamy but yet very fuzzy. I know that Fulltone's pedals are mostly beefed up other companies products, so for my base layout I chose tagboard version of fOXX Tone Machine by IvIark.

So this is my list "things to do to make FTM like UO (based on many schematics and this topic)":

1. change 100n input cap to 47n
2. change the "mid-cap" from 100n to 15n
3. in place of 3n3 add a switch with 1n and... 47n, 15n?
4. add before "fuzz 50k pot" 10k resistor
5. do some experiments with transistors and diodes (BC108C, 2SC828 (diffrent pinout) and 2n5088)


I have a few questions for you, if anybody could answer and confirm or correct me - thanks a lot!
- the "mid-cap" is this one I marked green on the picture below?
- switch goes instead of cap marked pink?
- what value will be fine for "fat mode" on switch? I found many version, depend on "mid-cut" cap value.
- 10k to fuzz pot must be soldered series to middle lug, right?


Greetings