Peavey Four-Tube Rockmaster Preamp for Distrotion/Overdrive

[Toppscore]

Hi. I purchased two older rackmount preamps that have yet to arrive.
They'll be my first rackmount preamps committed towards distortiontone/sound/effects.


This one is the Peavey RockMaster which has four 12AX7 preamp tubes
and the very original Peavey footswitch (read MOST ALL third party footswitches
are not 100% compatible and will not allow for a couple of functions).


Anyway . . . a few questions.
1) has anyone used the Peavey Rockmaster Preamp and what is your opinion? Types of music played?


2) I've read about swapping out preamp tubes with other brands
of 12AX7s and/or/mix/match 12AT7s will achieve interesting tones.
Read that 12AU7s ARE NOT good in this preamp.

Anybody enjoy certain preamp tubes over others? or preamp tubes to avoid?
Or combinations that are desirable? such as 2x12AT7s and 2x12AY7s?


3) I own 1950s/1960s Fender Tube amps. Sure, Fender tube amps do sound great
by themselves, but anybody have a preference using a rackmount preamp
with vintage Fender "combo amps" versus vintave "amp heads"?
Any experienced preferences?


Thanks for thoughts and opinions. Toppscore

[212Mavguy]

I have one, I liked it better after subbing in a 12at7 for v1, left all the others 12ax7. YMMV, good luck!

[Toppscore]

I have one, I liked it better after subbing in a 12at7 for v1, left all the others 12ax7. YMMV, good luck!

Thanks, MavGuy.
You like a bit more "punch" out of the first tube.
Will give it a test. Much appreciated.

[Bob-I]

I have 2 of these as well. They are decent sounding preamps even direct into the PA. I modded one of them to remove some of the midrange honk on the OD side and fatten up the low mids. It was years ago so I don't remember what I did, just do a google search and you'll see tons of stuff that can be done.

One hint, very important, the effects loops are problematic. Sometimes the preamp will cut out, sometimes one channel will cut out. Every time mine have done that its because of the loops. The quick fix is to just put a patch cable in the loop to pass the signal. Often cleaning the jacks will help.

The foot switch is easy to build, jut get a generic 3 button and get the rockmaster schematic.

[Toppscore]

Thanks, Bob. I have stored the notes. Toppscore