Gain delay with Warm Hi Gain voicing

[Dante]

I know this was discussed on the old Depot, but I don't know if it was specifically about this voicing. When I switch to a specific patch (that is using the Warm Hi Gain voicing), there is about a 2 second delay before the patch is fully voiced. That is, the gain is lower for that initial 2 seconds, and it takes that long for the patch to 'warm up' to the actual sound, a very high gain.

It seems to be much worse now than before, and I've just been avoiding that voicing altogether. Any thoughts?

[rnolan]

Hey Dente, it's a long shot but may ???? be related to another thread where he's coming from clean patch to higher gain but experiences significant vol drop, although unlike yours his (IIRC) dosn't come good and requires powers cycle to fix (and not sure if it then repeats..still working through it with him).  At MJMPs suggestion got him to try loop outs > amp to rule out the tail end of circuit, he still get the issue (would indicate that it's before the loop).  I'm thinking you "may???" have early stages of similar.  As I say long shot, but he's going to similar patches.
Is it always ? or after a while ? e.g. when you turn it on does it happen right away ? I don't recall this on the previous forum so can't add, MJMP may remember ?
Cheers R

[Rawk777]

Thread resurection!

Dante, have you found a solution?

I have similar issues when I switch from "dynamic" high or vintage channels to any other hi gain or vintage channels. It seems ok to go from Ultra to Warm, but it feels like using the dynamic channel is "cooling down the tubes' or something.

I don't know about the clean channels... I don't play clean that often .

[vansinn]

I used to have the same experience when changing to Voicing 10; however, the only preset currently using V10 no longer seems to have this setup delay. Inexplicable. Magic!

I do not have the answer, but, per intuition, believe it is either the Vactrols [that controls the tube's operating conditions] starting to take a looong time to go from one setting to another, or some capacitor(s) related to those setup circuitries, that are down in value.

And the debunker: To my knowledge, Vactrols aren't typically reported as going half-dead with age, so.. we're back to the guessing game - or better, elementary electronics measurements.. ;)
And I can't use my mini lab, as all is defunct due to selling my apartment.


EDIT: While Vactrols may not go SOA (slow of age), they're often referred to have slow reaction times, and some reports indicate this is often a matter of the surrounding circuitry not properly driving the Vactrol, so, could be I'm not off on thin ice after all..
Potentially interesting read: https://groupdiy.com/index.php?topic=43011.0

Methinks it's the surrounding electronics causing problems for [some of] the Vactrols.

[Dante]

Sorry, Rawk777, I don't have any breakthroughs to share. I have been using my MP-1 Classic primarily, the MP-2 is in a 2u rack with an FX unit for running straight into the board or a combo.

I think van Sinn may be onto sumting though....

[rnolan]

Possibly unrelated  :dunno: but I thought I'd throw it in, have you set the patch change speed to "Fast" (default is set to "Normal") in the System Edit > Midi Function Menu?
This option came with later EPROM update and isn't mentioned in the manual I have.  MP2 program changes were quite slow (particularly compared to MP1) before this update.

[vansinn]

Just to notice: I use fast preset change, and observe no audible artifacts during switching, compared to standard switching.
Will do a quick comparison and report on whether this affects the very slow preset change in voicing 10 that I used to have.

[Rawk777]

I did not notice any difference between fast and normal for the "gain delay" issue, but since I was set to normal, my mp2 is now faster to change patches !!!

p.s. To be honest, the speed difference is not too explicit, hehe.

[rnolan]

I noticed the speed difference allot when I first got my MP2 as I'd been gigging with MP1 up to that point.  The fast change upgrade came out pretty quickly IIRC and was important for me back then as I was changing patches allot in that band.

[Harley Hexxe]

I've never experienced any kind of issues like that with either of my MP-2's.

   Dante, has this issue always been there with yours. or it is something that developed, and got worse over time?

    I'll explain why I ask; I'm wondering if mis-matched tubes might cause an issue like this, or possibly one of the tubes may be getting weak,( such as the low gain tube ), and causing a lag when switching to a higher gain setting?
    Does it also do this when you are switching to a lower gain tube voicing?

       Harley 8)

[Dante]

Harley,

If I had to guess, I'd have to say it has been slowly getting worse...because I didn't notice it before. Honestly, I haven't used my MP-2 much, but I'll play around with it a bit to see what's going on. I would like to get to the bottom of this, as those tones are fantastic once they warm up, I'd hate to not be able to use them because of a simple glitch.

[Harley Hexxe]

Dante,

    I don't really know if the tube mis-match is to blame, but I suspect it may have something to do with it. At this point, I wonder if a set of matched tubes, or even a set of replacement tubes might fix the problem. If the 12AT7 is getting weak, and trying to come up to a higher gain level, that might explain the sag. Too bad you don't have a tube tester, that would take a lot of the guess work out of it.

[Rawk777]

Well, I am using a set of new tung-sol tubes (I dont' know if they are matched, but they are both new).

[Harley Hexxe]

Well, I am using a set of new tung-sol tubes (I dont' know if they are matched, but they are both new).

   Dante is using a 12AT7, and a 12AX7 in his MP-2. There is less gain in the 12AT7, and the MP-2 is expecting to see more.

[MarshallJMP]

The gain difference isn't that much if you replace a 12ax7 by a 12AT7, in the same circuit it will be 59 vs 53 (or 35.3 vs 34.5 dB)