Dual PPIMV? Anyone?

[ledvedder]

Has anyone done this to a 1987/1959 circuit? If so, I'm wondering how it works, and hopefully get more information about it. I have a PPIMV in my 1987 build that works pretty well, but I'd love to have dual switchable ones.

http://forum.metropoulos.net/viewtopic.php?t=45431

 

[harddriver]

Initially I thought what "What a ludicrous idea" then I looked at the layout and understood what it's purpose is......

You would need a power source to power the relays.

The only thing I can see is that you would have a footswitchable volume control via that relay from one Master volume pot to the other providing two separate volume settings like rhythm and lead volumes.

The only other option and a more simple option would be to install a 250K(my layout shows 250K)(I have not verified this value) audio pot off the 1 MEG master volume like Splawn used to do with his early modded Marshalls and it does not require a powered relay and it worked great for Splawn. The above complicated setup is interesting but you have a much simpler solution staring you in the face. Just have a tech install the solo boost pot in line with your bright volume pot of your 1959 plexi and be done with it. You would also need to a 1/4" jack to plug a single latching footswitch to engage the solo boost volume pot. Again... very simple no powered relays, there should be layout drawings of Splawn modded Marshalls floating around out there to show you how to do it.

Your PS100 also provides two separate footswitchable volume selections as well why not just use the PS100's capabilities?

 

[ledvedder]

Initially I thought what "What a ludicrous idea" then I looked at the layout and understood what it's purpose is......

You would need a power source to power the relays.

The only thing I can see is that you would have a footswitchable volume control via that relay from one Master volume pot to the other providing two separate volume settings like rhythm and lead volumes.

The only other option and a more simple option would be to install a 250K(my layout shows 250K)(I have not verified this value) audio pot off the 1 MEG master volume like Splawn used to do with his early modded Marshalls and it does not require a powered relay and it worked great for Splawn. The above complicated setup is interesting but you have a much simpler solution staring you in the face. Just have a tech install the solo boost pot in line with your bright volume pot of your 1959 plexi and be done with it. You would also need to a 1/4" jack to plug a single latching footswitch to engage the solo boost volume pot. Again... very simple no powered relays, there should be layout drawings of Splawn modded Marshalls floating around out there to show you how to do it.

Your PS100 also provides two separate footswitchable volume selections as well why not just use the PS100's capabilities?

Is it this simple? Just add 250k pot. Wire from middle wiper of high treble volume pot to middle wiper of the new 250k pot. Wire from ground lug of the new 250k pot to a footswitch jack, which would ground the 250k pot when engaged.

 

[harddriver]

Is it this simple? Just add 250k pot. Wire from middle wiper of high treble volume pot to middle wiper of the new 250k pot. Wire from ground lug of the new 250k pot to a footswitch jack, which would ground the 250k pot when engaged.

You would need to add the 250K pot, another 1/4" jack and a single latching footswitch. I don't think it's wired exactly as you specify. PM me and I will send you a layout that I have you can run by at tech or do more research on. It is quite simple and it should be easy for you are any tech to do.

I have an early Splawn modded Marshall and it has worked great for years. I have not verified the layout but I have used the Rythym and lead function control with a single latching footswitch in an amp build and it works great. So I think the other solo boost on the layout probably is correct as well. Yes it is shunting the 1MEG pot down somehow in value to bring in the level on of the 250K to set the higher level, I haven't completely disected how it works but it is simple. I'm sure you can find other public designs that are similar for a solo boost somewhere on the net.

Yes, I think it would be the simplest solution to your issue.

I don't want to post the layout publicly because I respect Splawns intellectual property.

Splawn's design used a stereo 1/4" jack that controls two functions. One controls the Rhythm/Lead modes and the other controls the solo boost function.