What abot #36 Marshall amp Slash used on Appetite?

[bluesman]

The myths told us this Plexi has an extra gain stage on the preamp, maybe like a Mastevolume... have anyone seen the schemo?

[puppiesonacid]

The myths told us this Plexi has an extra gain stage on the preamp, maybe like a Mastevolume... have anyone seen the schemo?

from what I know of the "myth" its actually a fact. I believe it was a marshall super tremolo 100 ( already had the preamp tube/hole for tube tremolo) which Tim Caswell modded with an add on board Tube gain stage. last I knew tim was starting this mod up again, or developing an amp with the mod stock..

[bluesman]

Yeah, I know it was a fact, and I think I know almost the whole history... probably will be simle by putting other gain stage to a plexi, trying different cathode resistors...

[AL]

I think that's actually #39.

Anyway:

http://www.slashsworld.com/equipment/th ... ll-o-mine/

Or hey, why not buy your own... for $5K

http://caswellamps.studioelectronics.com/products.html


AL

[bluesman]

I don't wanna buy it becasue it has other flavor when you build it yourself... some says it's #36, other 39.

[AL]

I don't wanna buy it becasue it has other flavor when you build it yourself... some says it's #36, other 39.

Really? Two different numbers huh? I didn't know that. Adds to the "mythology" I guess.

I wouldn't buy it either at that price. I think the article talked about an added tube gain stage. Shouldn't be too hard (famous last words )

AL

[puppiesonacid]

just use the soldano hot mod, probably similar in the ballpark as caswell and soldano used to collaborate.instead of a 6k10 or whatever that wierd tube is reconfigure the values for 12ax7? dik... im not that creative with amps.

[KHELSTROM]

Here is something I found on blueguitar.org . Its from some guy named Chip and here is what he has to say: http://www.blueguitar.org/new/schem/mar ... m_chip.pdf

"-I believe this is very close to the mods performed by Frank Levi in the late 80's. I first started tinkering with amps at that time, and dissected amps done by Levi, Soldano, Lee Jackson, etc.... so, nothing original here!"

[bluesman]

I think it's a broken link... just add a single 12AX7 stage, do not use to inputs, just one, and with that triode, put a 100k resistor to anode, 3.9k from cathode to ground, or something like that! I'm just thinking in something, it cant be so hard...

[KHELSTROM]

Has anyone seen this you tube clip and read the info on it? I guess this guy has the mod pretty much nailed down from reliable sources. I'm just not sure if he is offering to give out the mod info or if he is selling the service. I guess it wont hurt to email him. Here is the info if you don't want to go to you tube:

This is me playing on my Gibson les paul 1958 re modded with Alnico pro II by seymour duncan. London city is an exact replica of marshall plex and also from the same decade ! The London city is modded by drtube. This mod is the #39 SIR mod. Thismod can be done with marshall based amps, this one is a London city, in the past was this the dutch copy of the marshall super bass. We used this amp because of its great transformators used then !!! The mod makes the amp more than before, when we are finisched you will have clean channel, drive channel (normal jcm800 drive) and the #39 channel (the modded mode) also we provide a Fx loop in the amps wich is switchable, it will never be a tonesucker that way. I tried to play some licks for all you slash fans out there, please don't pay to much attention to the playing but just listen to the great #39 sound wich we create by adding an extra pre-amp tube and a circuit board in the amp. This is a direct copy of the real #39. We got all our info from people direct involved with the real #39 rented by SIR that days. Please if you have any questions about the mod, or like to have it too, feel free to email meat : len@drtube.nl . I hope you like the mid '80 slash sound as we do, there should be a lot more amps sounding like this one out there !!!!!
please listen to the sound of the amp its great and doesnt cost to much !!! give drtube a call at : len@drtube.nl

Here is another great but different sample of the mod:

[bluesman]

2nd video sounds amazing... and great rebel attitude!

[AL]

Found this over at the Metro Amp Forum. There's a discussion with some mods and a layout.

http://forum.metroamp.com/viewtopic.php ... 0617f2bee7


AL

[AL]

Also found this at Ampage - from around 2000

Benjamin-

If your customers want a really heavy, high-gain sound, and that's all they want (no ch. switching, etc.), here's one that I have used for several years now. No extra tube stages.

I can't take credit for it, I copied most (if not all) of the component values from an already-modded amp back when I was just getting into amp mods... I think (and this is by no means certain)this mod originated with Frank Levi (spelling??) in LA......

Hard to "draw" with words, but this is simple enough, so hopefully it will translate OK:

-about 34k resistance from input to first stage (parallel 68k input resistors)

-1st stage: 3.3k c resistor, parallel with 330mf

-out through .022, into 1meg aud. pot with .001 bypass cap, into 470k res. bypassed with 470pf cap, into second stage.

-2nd stage: 2.7k c resistor, with .68mf

-out through .022, into 1 meg aud. pot bypassed with .005 cap, into 470k res. bypassed with 470pf cap, then into 3rd stage.

-3rd stage: 3.3k c resistor, parallel with 330mf

-change tone stack cap from 470/500pf to 220 or 250pf

That's it. Pretty simple. The "Low" sensitivity input can be removed and the additional pot added there. This mod sounds great with head/4x12 cab set ups. Don't know how a combo would fare. Keep the mids low, set gain on both pots to about 6, and let 'er rip. If the amps too bright, remove one of the pot bypass caps.....

I've squashed many a Boogie-owner with this one. Best part is the parts cost squat, and it takes only a few minutes. Easily reversable, too. Hint: the second stage is a stock first stage. For less work, just swap wires.......

Hope this helps!

-Chip