Gain delay with Warm Hi Gain voicing

[MarshallJMP]

Ok I just had a look and it seems F4 (see tube schematic MP-2) is only on ,on voicings 4,6 and 8.It controls 2 Fets (Q322,Q317) and the 2 vactrols on the tubeboard.

[rnolan]

Mmmm, you may have found the culprit, go MJMP  :whoohoo!: .  Interesting I've never used those voices.

[Rawk777]

I'm not really good with schematics... Does it mean there is something I can do to fix the problem?


___
**Wow... the delay of my question is more important than the delay on these MP2 voices!

[MarshallJMP]

Well have a look on the schematic 852, you will see on the bottom left side level shifters, there you will find F4.

[rnolan]

Hey MJMP, I saw those, I'm not sure how to interpret them though (and what is F4 when it's at home ?).  Would replacing the 2 Fets (Q322,Q317) and the 2 vactrols on the tubeboard fix it ?

[MarshallJMP]

Well those Fx switches various fet's on and off to get different sounds. If you look around the same schematic you will find those Fx all around usually going to the gate of a FET and the base of that 2N3904 transistor that switches those vactrols.

[rnolan]

Hey MJMP, The bit I'm struggling with is - so there are 3 vertical rectangles side by side (which represent ??).  MP2 voice settings on the left and F assignments on the right.  I couldn't fathom/read how the voice settings match up/are assigned to the F settings, so I'm looking for voice 4, 6 & 8 on the left but struggle to see how they relate/connect to F4 (just following the horizontal connection lines).  Obviously I don't know how to read/interpret this kind of schematic  :facepalm: .

But the question Rawk777 (or Rawk 111, 111, 111, or Rawk rwx, rwx, rwx.. sorry couldn't help it, bit of a unix thing..) needs answering is can it be fixed ? Would replacing the 2 Fets (Q322,Q317) and the 2 vactrols on the tubeboard fix it ?

[MarshallJMP]

Ah ok, well depending on the voice you select, some F's will go on and some go off. I have a list  (maybe I even put it on the depot somewhere) which are on on each voicing.

For Rawk777, those vactrols are very slow devices so it could be that these are the problem.Maybe other mp-2 users could try to mimic the settings you use and see what happends?

[vansinn]

Well.. I can tell that my two MP-2's react at different speed on Voicing 9+10 and one of the 4/5/6 ones; can't remember which one.
I definitely believe the Vactrol's are getting slower at going from one to another setting on one of the MP-2.