What model Marshall Do I Have?

[888guitars]

Ok when I get it open tomorrow I will get a better pic of it. I need to look at the schematic to see where it is patched in

[dumbassbob]

It has a 50/100watt switch on the back. Will this affect a PPIMV ?

I would go over to metroamp,it is all Marshall..I would pull that 50/100 out...Thats a Nice amp..Also when you play with a band you will cut through,or if you use an attenuator, Keep the bright cap.....

[888guitars]

ok it IS a PPIMV in place of the presence. I actually like it! I am going to move it to the back in place of one of the 4 speaker jacks. then put my presence back in. I think I want control of that.

[big_teee]

ok it IS a PPIMV in place of the presence. I actually like it! I am going to move it to the back in place of one of the 4 speaker jacks. then put my presence back in. I think I want control of that.

Most stick in on the back like you said.
On my 2204, I have the Pre and Post Master volumes, and the presence.
All on the front, I drilled the chassis, so I could put them where I wanted.
I think the PPIMV, must offset the Presence, cause I can't tell it does a HellOfaLot.
T

[jamesmafyew]

Exactly, the PPIMV does affect the presence, because it's inside the feedback loop -- it upsets the ratio between the + and - splitter inputs. The presence will only really work "right" when the PPIMV is all the way up. That being said, the whole point of it is to allow the PI to be overdriven at a lower volume. NFB breaks down in a clipping power stage anyway, including the presence control, so if you're trying to approximate "cranked tone" the PPIMV is often just fine for that purpose.