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MARSHALL Valvestate VS100r additional mods
MARSHALL Valvestate VS100r additional mods
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Old 15th September 2009, 03:02 PM   #1
screamersusa is offline screamersusa  United States
diyAudio Member
Join Date: Jun 2005
Location: Fort Collins Colorado
Default MARSHALL Valvestate VS100r additional mods

I found a few VS100 mods posted by Costipato and references to
I did most of those mods and they do make a nice difference but not quite the drastic change I was looking for. So here's a few more.
I HATE the clean channel with a passion.
Rewire the tone stack to a fender wiring. Much better even without changing anything else. The clean channel becomes usable with a more bell like quality instead of a nasaly anemic weakling you want to smash with a sledgehammer.
Personally I prefer the clean channel with c39 (brite cap) removed but you could toss a switch in there as well.
No bad but still a little, ah er, flat and lifeless. hmmm....

Cut the trace between C33 and IC4 pin 5. Stick a unity gain fet in there
according to this schematic. I'm sure someone could make it better and without needing any source resistor (more second harmonics). You are reusing the original input connections so you don't need them on the fet preamp.
The idea is to switchit in and out with a true bypass switch on the panel
without a noticable level change.
The change appears subtle at first. When you try chuck chucking the guitar
with a light left hand mute (a la Hendrix/SRV) the change punches you in the face. The the harmonics pop right out. Overall the amp becomes much easier to play and you don't have to fight to get any response out of it. This leaves you with the best of both, a fendery clean and the standard marshall overdrive in ONE stock amp.
Excellent patch for someone stuck with a VS100 as a main or backup amp
in our nasty economy.
Cheers to all the other financially challenged DIY ers out there.
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Last edited by screamersusa; 15th September 2009 at 03:05 PM. Reason: forgot something.:)
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Old 17th July 2011, 06:05 PM   #2
pierogoku is offline pierogoku  Italy
diyAudio Member
Join Date: Jul 2011
Excuse me. The mod is ok? I am who has invented the mod on the ODs channels. Now i want modded the clean channel. In this mod where is LK2?
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Old 17th July 2011, 06:07 PM   #3
pierogoku is offline pierogoku  Italy
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Join Date: Jul 2011
Hi! I am who has make the mod on the ODs channels.
Now i want mod the clean channel. Where is on the schematic LK2?
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Old 3rd September 2011, 09:16 PM   #4
zaikar is offline zaikar
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Join Date: Sep 2011
I'm just about to do some mods on my VS100. Did you guys have done anything else to your valvestate?. Any recomendations?. Thanks!
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Old 1st June 2012, 12:54 PM   #5
spudjds is offline spudjds
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Join Date: Dec 2010
Looks like an old thread but I would like to know if the information from the first link referenced is available anywhere - I get a 404 error on that link.
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