master volume ab165 silverface

[TWANG]

I am just not getting it from the available examples.. robrobinette for example.
I have already modified this amp a pretty fair amount. (I'll get a gut shot up soon)
and the owner still wants to get it dirty..
he's running @ 4ohms

He wanted a vvr but I've never done that in anything but single ended low watt amps.
Not even sure where I'd put it in this.
I think a ppimv would do it.. cause it IS dirty already, you just have to crank it.
He normally uses a peavey classic 30 playing out.

For whatever reason.. (I was pretty sick for a while I don't think that helped)..
I can't figure out the differences.. like robs amp pics are NOT like my amp
that I can see.

a layout that shows what would be fantastic.. a schematic, too, of course.
I was looking at the lar mar and frondelli but saw another with the mv on the back of the amp.
I still have the former IEC hole (out) plugged so I can use that. that would be best, I think.
It was a 1Meg pot... seemed pretty simple. but again.. where on this amp?
thanks.
Twang!

[Roe]

larmar works well

[Stevem]

That line of Peavey amps have a far less robust power supply ( current output ) and far smaller output transformer then that Fender , so your beating yourself up trying to that level of dirt ( frequency roll off) and play feel out of that fender!

Change over to grooves tubes China made 6L6 tubes in a number 1 rating and I bet your then 50% of the way closer to what this player is wanting!

[martin manning]

This is pretty close: https://ampgarage.com/forum/viewtopic.p ... 33#p254033 If you still have the bias balance set-up, the connections to the bottom of the MV pots come from the bias balance pot wiper and the turret with the two 10k's on it. I think I would just remove the two 220k's and tie into the existing eyelets, and maybe extend and use the existing grid wires. You'll need a 250k dual pot, and a place to put the two additional bias caps. Maybe even hanging them off the pot lugs would work.

[Paul G.]

Or you can use the simplest of them all, Type 3 -- you place a 1M pot between the legs of the PI output as a variable resistor. As you turn it down, you are causing phase cancellation which brings down your volume. The bad part is that it is never completely out of the circuit, so wide open is affected, but if you never play dead nuts clean it may be an option. Tightly twist the wires and route them thoughfully and you should be able to put the pot on the back panel without extra noise.

Trainwreck_MV_Type3.png

[TWANG]

Thanks for both of those.. added to my folders.
Perfect!


TWANG

I tried the simple MV first. It works perfect and does exactly what was needed.
I know he'll never run it at 10 for clean so this is great.
I can get all the dirt I built into it earlier at very low volume. Certainly
low enough and powerful enough for the gigs he plays.
And it's quiet as all get out.. which means yay for the studio engineer.
Thanks again..
Now I have to do one in a Tweed.