Dual Rectifier revision?

[streetwise]

Hi guys

I'm confused about the revision of my old Dual Rectifier I bought a year ago. It's missing the serial number plate and I can't find the number on the PCB either. I was told the serial number was somewhere around 2000 (can't remember it exactly), no idea where the seller got that from.

It says RF-1G on the PCB, which means Rev. G right? But there's also the serial loop, small logo, attached power cable, Mark IV OT (562105 with outputs labeled 4 / 4 / 8-16 / 8-16), 561136 PT, and on the choke it says 2.7.1992. All these are Rev. F specs right?

The orange channel sounds very dark and muddy compared to red channel. Red channel sounds great with all knobs at noon, but on the orange channel I really have to crank the presence and treble. Is this normal?

 

[JCDenton6]

That sounds like a transitional rev G to me (the pcb board reading RF-1G is a comfimation of this), using some parts from the "F" revision. Silverwolf got one of those built in a "pre 500" blackface w/ chrome chassis.
The orange channel (cloned to modern) is darker than red for sure. I wouldn't say muddy, probably dependent on preamp tubes .

 

[streetwise]

That sounds like a transitional rev G to me, using some parts from the "F" revision. Silverwolf got one of those built in a "pre 500" blackface w/ chrome chassis.
The orange channel (cloned to modern) is darker than red for sure. I wouldn't say muddy, probably dependent on preamp tubes .

I've tried changing the preamp tubes but it won't help (actually I think both channels use the same tubes if schematics online are correct.) I'm guessing it's a failing capacitor or LDR. I already had to change the 100nF filter cap that was shorted and was blowing the fuse...

 

[blazer986]

Your amp is probably close to 20 years old at this point. That seems to be about the time they need a little TLC, new caps and such. That may explain some of the muddiness.