Mesa V Twin mod
From alighto–(at)–ualcomm.com Wed Nov 23 18:51:18 CST 1994
I got this info right from David Goodman at Mesa Boogie. I have
As many of you V-twin owners are aware, the volume boost from blues to lead
If you open up the vtwin, you can replace 2 1/4 watt resistors to bring the
R11 and R12 are located (as viewed from the playing position) just below
I performed the mod, it works about right. It is possible that you could
Be careful, the annular rings on the circuit card are quite small and it is
There is an amazing amount of solid state parts in a V-twin. And a very
Mesa told me they would do the mod for free for me if I paid shipping both
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Article: 33025 of rec.music.makers.guitar
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From: alighto–(at)–ualcomm.com (Al Lighton)
Newsgroups: rec.music.makers.guitar
Subject: mesa Vtwin volume mod FACTS
Followup-To: rec.music.makers.guitar
Date: Fri, 18 Nov 1994 08:57:01 -0800
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incorportated this mod and it works.
is unuseable. Maybe later versions were fixed, mine was definitely way to
loud in lead mode.
voume down to just a small boost over the blues volume by changing
resistors R11 and R12. R11 is a 1 Meg ohm stock, install a 220k ohm in its
place. R12 is a 100kohm, install a 120kohm resistor in its place.
the gain pot, just above a small 3 lead transistor, about 1-1.5″ from the
left edge of the PWB. The resistors are side by side, kind of straddling
the small transistor.
lower R11 a little bit more, since there is still a reasonable volume boost
to the lead channel. If all you want is a gain boost, but not a volume
boost, lowering R11 a bit more might work I have *not* tried that.
pretty easy to lift a pad. I suggest clipping the original resistor in
half and pulling each side out individually to minimize strain on the pad.
high parts count overall as well. And the thing is a bitch to take apart
and reassemble.
ways. If you are a clutz with a wrench of soldering iron, take them up on
it.
Al Lighton
[alighto--(at)--ualcomm.com]
I just pulled my V-Twin out of retirement. I hadn’t used it for a number of years & decided to try it again. It is a fantastic clean preamp that gives you a nice full sound with lots of definition. I use the clean channel on all the time & the boost for crunch or leads. I have the first version with no mods, but I use a nice old Telefunken 12AX7 on the right side (clean channel) & a black plate RCA 12AU7 on the left side (boost). (The tubes are in opposite positions from where the seem like they should be.) The low gain of the 12AU7 balances out the ridiculously high boost when you use the stock 12AX7. For leads it’s pretty much right on & I just roll off a little volume on my guitar for a crunch rhythm. I can’t believe it took me this many years to figure this out! I hope this helps someone else. It’s a hell of a lot easier that modding the PCB.