XXL Build report

[audioguy]

After struggling with the Blackfire with a Marshall tonestack for a while, I put it to bed and moved on to Marty's XXL.
This thing crushes! Its the exact distortion I was looking for.
I had to do a couple of part subs- Instead of 1n4002 I used 1n4005,  the 27n was replaced with a  29n and instead of the 56n I had to use a 68n. Even with these subs it sounds amazing, but of course I have a couple of issues.
Drive control doesnt do much for about 90% of the pots rotation, then for the last 10% of the turn it really cranks. Im using the recomended 100kA, should I try a reversed audio log to remedy the bunching up of the gain?
Second- the Warp control seemingly does nothing. I figured I would hear even a little something... but I get zip. Would that be due to the 2 cap subs, or the diode swap I had to do? I used the 100kB as recomended, and I tested with TL072 and a 2262, but no difference at all.

Thanks Marty for a killer project!

Audioguy

[d95err]

Drive control doesnt do much for about 90% of the pots rotation, then for the last 10% of the turn it really cranks. Im using the recomended 100kA, should I try a reversed audio log to remedy the bunching up of the gain?

By your description, I'd say a linear pot would work better. A reverse pot could cause the opposite problem (everything happening in the first 10%).

Dial in a sound you really like, then measure the resistance of the gain pot at that point. Use that resistance to calculate approximately what position that would correspond to on a linear or reverse log pot. That should give you an idea of which pot would work best.

[MartyMart]

Thanks for giving this a go and for the report !
The gain pot is buched up also on the original 
I didn't mind as it's a "high gainer" anyway, however a linear pot may
help, but probably wont do much after 50% rotation ....
I found a very slight difference when using a TL072, ( better ) but the warp function could
use some "tweaking" ... see the comments by stm on the original XXL posts for ideas

Marty.

[audioguy]

I'll try a linear tonight and let you know what I find.
As for the warp, I'm going to try to get the correct caps in and see if that has any change. Im surethe caps will help with my tone sweep, it goes from too mushy to too shrill very suddenly.
Even with the Warp not working correctly, this thing is still a winner!

Thanks Marty

[Mark Hammer]

Warp controls are one of those things that only show up if you pick a certain way, and don't produce an audible effect on their own the way a distortion amount or tone control might.  There are a whole constellation of situations where warp appears to change nothing.  Not to worry.

[audioguy]

Interesting info, thanks Mark!
Maybe I'll take a trip to Guitarcenter  for lunch and see if they have one I can play with.

[lowstar]

i a/b´d mine against the bass version, there was a big difference, but it could be due to some caps that are different. the warp control really made the tone fat and fuzz-like in the extreme settings. i couldn´t get there with my clone, 072 or 2262. the funny thing is, as i wrote in my earlier post, fed with a sinus signal from a lab tone generator, the warp control has an extreme effect, and you can absolutely hear the neutral position off left. but with guitar or bass, it is really so barely audible that sometimes i wonder if i´m just imagining it (just like the offset null control on the tube reamer-honestly i cannot hear a difference at all, and nor can anybody i played it to.maybe i should recheck it ?!?)

but nonetheless, it sounds good already, it´s a fitting sound for king crimson´s "red" ;-)
i just would like to be able to coax more sounds out of it.

cheers,
lowstar

[jrc4558]

"Red" you say? I'll sure give it a try. Which IC's did you use?

[MartyMart]

A friend of mine has an XXL, when used with his "live" rig ( huge 2X Marshalls ) the warp does make a much bigger
tonal difference !
Here at "home" level it is very subtle ... I think a cranked rig makes a lot of difference

MM.

[Mark Hammer]

I always had the impression that the "warp" control on the XXL was the basis for Jack Orman's article about "warp" controls in general.  My experience with them is not at the sort of volumes some folks find normal, but to date the effects have been noticeable if you knew what to listen for, but not so noticeable that if you didn't understand them you would be able to easily hear them.

[lowstar]

@constantin: i used both 072 and 2262; i liked the sound better with the 2262, but then the warp control has zero effect. with the 072, the warp control does a little something, so at the moment i have the 072 in. i mean the bassline of red, by the way! if you play both the lower and the upper bass voice at the same time (3rds), it sounds very tight because the xxl is kinda "lean" sounding.

@mark and the others:i ony play with headphones at home and with the original (bass) xxl, the effect was very prominent, regardless of volume.

cheers,
lowstar