Help with master volume

[Irkin_Bollikans]

Hello all, I have a old pa amp that I'm in the process of converting for guitar use. Wife is tired of the loud testing so it's time for a master volume. If someone would be so kind as to tell me where the best place to implement this, I'd be most appreciative. Below is the schematic of what I am working on

[Latole]

Why not this one ?  ; https://robrobinette.com/Generic_Tube_Amp_Mods.htm#Lar-Mar_MV


Trainwreck Type-3 Master Volume

There are many master volume options but the Trainwreck Type-3 is very easy to install and works as well as any other master volume I've tried in any of my amps. This master volume controls the signal level feeding the power tubes so you can use it for lower volume distortion and to control the balance between preamp and power tube distortion. It works by mixing the two phase inverter output streams together and they cancel each other out. Less resistance = more signal mix and less output volume.
For the Type-3 master volume you simply add a 1 mega ohm audio (log) pot and two wires. It's easy to temporarily alligator clip the pot into the circuit to give it a try. When the Master Volume pot is set to max the master volume circuit virtually disappears and will not color the amp's tone.
You can place your master volume pot anywhere but you may have to use shielded wire to prevent noise or oscillation. I use RG-174 when I need shielded coax in an amp. Only ground one end of any coax cable in an amp, preferably the signal input end, to keep from forming a ground loop. If you keep the wire runs relatively short and away from the power transformer end of the amp you should be OK without using shielded coax.

[Irkin_Bollikans]

Trainwreck type 3 mv is not working in this circuit

[sluckey]

You have a paraphase inverter. It's not gonna like any of the post PI MVs. About all you can do is put a standard volume pot in front of the PI.

[Irkin_Bollikans]

You have a paraphase inverter. It's not gonna like any of the post PI MVs. About all you can do is put a standard volume pot in front of the PI.

Thank you so much. If you cant tell, I dont have much of an idea what I'm doing, but I've managed to piece together a few amps. If you could make any recommendations to changes I should make, please chime in.

[d95err]

Trainwreck type 3 mv is not working in this circuit

In my (limited) experience, the single ”crossline” PPIMV doesn’t work well in any circuit.

[d95err]

You have a paraphase inverter. It's not gonna like any of the post PI MVs.

Why not? Just curious. I’ve never built an amp with paraphase.

Half the threads discussing the 5e3 or Princeton on different amp forums seem to be about modifying the PI to change the distortion characteristics of the amp. So my intuitive approach would be to use a (”Lar-Mar or dual pot) PPIMV rather than pre-MV in order to try to preserve that character.