I like my homemade Bluesbreaker, so I thought my eBay Marshall Guv'nor GV-2 would sound
good. I didn't like it at all, on to the shelf it goes. I could do the "mods" thing where I audition
different diodes, change a few caps, change the opamp and declare the result "Organic, luscious,
vintage, soaring, sustaing, spiritually uplifting". Or "Want to have the sound and tone of the guitar
gods!?!", as Robert Keeley would say.
Instead, I'm going to go all psuedo-rational with "Lucious Circuit Analysis", "Side by Side
Comparisons of the Gods$%@!%", lets see how that goes.
What's wrong with this picture? Well, the circuit cuts all the lows and highs. And I don't like like
that. I'm sure lots of people do. But my Morley JD-10 is a diode clipper and I really like it. What is
the difference?
Well the JD10 doesn't cut all the treble. The JD10 has a "Rock" switch which shorts R6 for a gain
boost and treble cut. So let's do a 30-minuite hack job on the GV-2. I would leave the old black
Guv'nor alone, sell it on eBay, and buy a JD10 plus change. But I have the cheapo silver one.
Close enough, the 0.001 treble booster cap has less effect at high gain, a bit like the JD-10 "Rock"
setting. But the diodes are way different from the JD-10. Do diodes in the feedback loop change the
frequency response? You bet.
Lookin' good, like she should. As Johnny Winter would say, and this does remind me of a cranked
MusicMan SS preamp, tube output. So the above schematic is what I did.Sound sample. mod GV-2 first, JD-10 second. (B.C. Rich switcher in action)
I suppose the reduced treble at high gain is debatable, enough for one day.
1. Orange Squeezer Compressor Pho...
