Second Master Volume

[GtrScott]

Thanks Jana! I still have more questions but I need to get info together first.

I am still curious as to why you need to have a full zero volume to max volume with each 1 meg pot.

I have a 100w Marshall Plexi that has this, two master volume mod, and I really like the way it works for live work. I had another amp with a boost volume and this second pot changed the tone a bit when it was kicked in. I don't recall if it got bright or muddy, I just didn't like the change.

The mod on my Plexi, is very transparent so I'd like to replicate it.

[drz400]

Thanks for the idea Jana although not quite what I'm trying to reproduce.

My layout is like the attached schematic. The problem, I think, is that signal is bleeding back through the pot that is supposed to be off.

What's the simplest way to switch and not get the bleed? A different type of switch on both sides of the pots?

Thanks again!

Scott

Switch both in and out and do it with Vactrols, it wont pop

[Jana]

Can you open up your plexi and copy what was done there?

[GtrScott]

Switch both in and out and do it with Vactrols, it wont pop

Thanks!

What's a Vactrol?

Can you give me a PN and maybe a sketch of how it connects?

[Jana]

Hoffman has them,

http://www.hoffmanamps.com/MyStore/perl ... =184988460

scoll down to see it.

Check out the Mesa Boogie schematics, they use them a lot.

[GtrScott]

Hoffman has them,

http://www.hoffmanamps.com/MyStore/perl ... =184988460

scoll down to see it.

Check out the Mesa Boogie schematics, they use them a lot.

Thanks Jana, I'll check it out.

Can you open up your plexi and copy what was done there?

The mod amp is installed upside down so all I see is the underside of the board it's build on. I don't want to remove it because: 1) It's my main amp and I use it all the time. 2) I'm to chicken to risk breaking it.

What I see, I now realize, is a relay and a diode. I think that's all there is to it but I'm not sure.

[drpicklo]

Hey guys - I would like to do the same thing to my Overtone special. Do you think this is possible? The MV has a precense pot right next to it, both post PI. What do you think?

The passive fx loop in this amp isn't allowing my clean boost pedal to work right.

Thanks in advance!

[ChrisM]

The MV is before the PI in that amp, yes you could implement a second MV/boost if you feel the desire.