Ultra Mods

[kc2eeb]

I have a copy of this from Ken Fisher. I met him at Ampeg.
Pages 33,34, and 45 are great info if you're thinking of modding
things. Hope the link works.
http://www.blueguitar.org/new/schem/trainwreck/the_trainwreck_pages.pdf

 

[JonnyB]

@kc2eeb, Thanks for that. Very useful information.

 

[m0jo]

Couldn't agree more Rob, although I'm just getting in to modding myself I have no illusions on how difficult it is to do. I also have no intention of copying and selling on a module - thanks for the offer fuzzboat. Anyway I like getting my hands dirty :wink:

Rob, at the risk of sounding sycophantic (I looked it up), I'd like to thank the few established modders like yourself who are open to share ideas with others and willing to take the time to help out with advice on this forum. It's much appreciated. I think I speak for most 'tinkerers' on this forum when I say we are not out to steal your ideas, we just like messing with stuff! ++Karma

I am more than happy to help in anyway I can and you didn't come across as having those intentions at all. I just wanted to address that one particular post that directly suggested buying Pete's work with the intention of copying it. Not only isn't that cool, it's not in the spirit of a DIY discussion board at all.

Quite right...although to be honest, a number of people have certainly done such a thing in the past..I've seen a couple of mods that were direct copies of somebody else's work....

Yep, have heard this rumour as well ..

Anyway, I'm thinking of modding my friend's Ultra now.

But what other things can be done to it? (simple things ..)

 

[Jaded Faith]

What are you looking for from it that you aren't getting now? That's always the best question to start with when it comes to tweaking.

 

[m0jo]

What are you looking for from it that you aren't getting now? That's always the best question to start with when it comes to tweaking.

Well .. mostly it's making it a usable tone

It has a 4.7nF C3 cap atm, I think changing that to a 2.2 should clear some of the lower mud.

Then what I'd like to tweak, if possible, is the clarity.
Mostly the top end is dull / undefined.
If this could be tweaked out with some simple things that would be awesome.

EDIT:
Just spotted your comment about cleaning up the mids on the other page, I'll try that!

 

[JonnyB]

Well I took the plunge and did the mod. Here is what I changed: C3 swapped to an orange drop 0.001uF, C14 went to a silver mica 390pF and R31 is a 47K metal film. I also installed a couple of ruby 12AX7AC5's. I tried these before the mod and didn't notice much of a change from the EH 12AX7's originally installed

The difference in sound is like chalk and cheese. The gain on tap is immense! Whilst it's probably not much more in actual db's from before, it is now much more usable and musical. The mids are much clearer now. Upper harmonics just spring from the guitar like magic. It's actually quite a unique tone and although not great for rhythm, it's great for soaring lead lines in the vain of Satch and Vai. Have I made it into more of an Ultra XL now?

A big thanks go out to everyone who gave advice on this, particularly JF. You rock man!

Here is a pic of the after mod:-

 

[Jaded Faith]

Excellent news and glad to hear you like it. Your tweaks have made your Ultra more like an Ultra XL now. There are no changes to the gain from your work. But you are correct that it will certainly make what's there much more usable due to the revoicing of the midrange and pumping less low end into the gain stages.

 

[I is be sexy]

Hey guys, I'm thinking of modding my Ultra as well. I want to make it into something that's like a mix between a Peavey Ultra+ and a Mesa Mark series: super tight but powerful lows, lots of cutting mids, smooth but present high end, stuff like that. I think someone before me tried modding it because some of the values aren't stock, but oh well. Here are some changes I was thinking of doing:

For C3 (currently .0022uf), I was thinking of putting a .001uf cap, but would that lack power? Should I go .0015uf instead?

Right now there's nothing in C10, should I put something there? What exactly does C10 do, anyways?

Do C14 and R25 (R31 on some boards, I think) control the amount of mids, or the main frequency range of the mids, or what? Currently they are 180pf and 33Kohms, respectively, and based on some suggestions here, I was thinking of trying 250pf and 47Kohms

I've heard a couple different things about R1, R2, and R3 - currently they're all 150ohms, which is (I think) not stock, is this a good value for them?

I'd really appreciate any help with these questions and any other suggestions you guys might have. Thanks!

 

[I is be sexy]

bump?

 

[Deisel401]

Would these mods apply to an SL+ also ? I think mine could be a bit clearer in the mids. I've changed my C3 to an Orange Drop .0015 and R1, R2, and R3 to 150 ohm 1/2 watt resistors. My SL+ is dated '08 and has the black stripe chrome faceplate. And I've noticed on the GRAILTONE pcb schematic that there is no R3 there, but there is on my SL+ pcb. What would this indicate?

 

[SacredGroove]

And I've noticed on the GRAILTONE pcb schematic that there is no R3 there, but there is on my SL+ pcb. What would this indicate?

R3 is on both, module and pcb layout. :wink:

 

[Deisel401]

Ah . . . . you are right. The R3 on the pcb layout on Grailtone is at a different location than on my SL+ pcb.