PPIMV on a 79 jmp 2204

[Kylelagz]

A. can some one explain just what it does and B. would it improve the sound of my amp? from what i can tell it gives you a more natural saturated distortion and that sounds like what i've been looking for. am i misinformed or is this not a good combination with this amp? or is it a match made in heaven (or hell depending on your preference!) either way id like to hear your thoughts on it!

also, happy holidays!

 

[kamran]

A lot of what people contribute to power tube saturation is actually the phase inverter tube (a 12ax7 but technically part of the power amp) getting slammed. Traditional master volumes come before the PI tube, so the only way to get it to work its magic on the sound is to crank the amp. A Post Phase Inverter Master Volume come after the PI (hence the name) so that you can regulate the volume while still slamming it, and it can have its positive impact on tone that way. I don't think it has as much of an impact on newer amps but they're highly recommended for super leads, and a lot of people who install them on 2203/4s are very happy with them. I don't have any hands on experience with them but I plan on having my super lead modded with one very soon.

 

[Kylelagz]

Thank you! my only other question, am i able to use both volumes or just one?

 

[kamran]

I'm not sure, but since the original master volume comes before the PI if its set low you're rendering the PPIMV useless. Im guessing the original master will still control how much of the signal the PI gets hit by, so you'd want that set high enough so that the PI thinks the amp is still being cranked, then use the added master volume to control the overall output. Of course, this doesn't equal power tube distortion, the only way for that is to REALLY have the amp cranked. It just helps capture the essence of a cranked amp since the PI being driven is a pretty big part of the sound.

My question would be, how popular are PPIMVs among the bg names that tour with super leads. (As opposed to a regular pre phase inverter volume, like the 2203s already have)

 

[Crunchcity]

My question would be, how popular are PPIMVs among the bg names that tour with super leads. (As opposed to a regular pre phase inverter volume, like the 2203s already have)

That crowd would seem (you would think) to be able to play their amps louder negating the advantage but in this day and age even that sector is under fire.

 

[kamran]

Very true, but even the biggest acts play small club shows for novelty every now and then. It's these scenario I'm wondering about.

 

[kamran]

The smashing pumpkins played at a little theater I play at all the time about a year ago, it got the venue shut down for a while lol.

 

[jcm800gridlock]

I have the ppimv mod on my 1987x and it works great. I doubt that I would have owned the amp without the mod.

I would make sure that the mod is reversible and no holes are drilled, so not to mess up the value of your 79 JMP should you decided to sell.

 

[Purgasound]

A 2204 already has a master volume. A PPIMV added to that is really not going to make any difference. The PPIMV was intended to be installed into amps that did not already have a master volume.

I've done it to a 2204 before and it was a waste of time. I removed it and just use the stock volume knob.

 

[jcm800gridlock]

A. can some one explain just what it does and B. would it improve the sound of my amp? from what i can tell it gives you a more natural saturated distortion and that sounds like what i've been looking for. am i misinformed or is this not a good combination with this amp? or is it a match made in heaven (or hell depending on your preference!) either way id like to hear your thoughts on it!

also, happy holidays!

I assumed that your JMP a four holer NMV?

 

[Purgasound]

I assumed that your JMP a four holer NMV?

The title says 2204, chief. That is a master volume model. The version you are thinking of would be the 1987.

 

[jcm800gridlock]

The title says 2204, chief. That is a master volume model. The version you are thinking of would be the 1987.

Corrected, guess I missed the 2204 in the title.
Thanks