Metropoulos Forum

He is a Paul Gilbert modded marshall I took photos of awhile ago.. thought you guys would like the pics
http://s1295.photobucket.com/user/jerem ... 1.jpg.html

Kinda looks like Lee Jackson's work.

Im just learning so it all looks the same to me. Lol

This silicon reminds me of CARR amps... Every part there is just coated with silicon!

I know. Why do they use so much silicon?

white noise wrote:Kinda looks like Lee Jackson's work.

I am pretty sure Lee Jackson did some, if not all of the work on Paul's amps back in the '80s. I use to work with Lee's girlfriend at the time.

I see only 3 preamp tubes. One of them must be PI, so it's a 3-gain stage amp with CF+tone stack... Kind of JCM 800 with more gain.

Jeremy1283, I think CARR uses that much silicon because it's holds the parts together + if some part will touch another part it will not conduct. For true point to point wiring I look at "BC Audio" or Audio amps like Jadis. It's an ART to wire them like these guys do...

Haze13 wrote:I see only 3 preamp tubes. One of them must be PI, so it's a 3-gain stage amp with CF+tone stack... Kind of JCM 800 with more gain.

Jeremy1283, I think CARR uses that much silicon because it's holds the parts together + if some part will touch another part it will not conduct. For true point to point wiring I look at "BC Audio" or Audio amps like Jadis. It's an ART to wire them like these guys do...

What does a cf tone stack mean? Just the type of resistors.
I dont see that glue in any othet amps.. Well I'm learning. Thanks for the input.

CF - Cathode follower. In the Marshall schematics (Plexi, JCM800, JTM45 and others) it's what comes before the tone controls. Vb2 is the Cathode Follower.

Haze13 wrote:CF - Cathode follower. In the Marshall schematics (Plexi, JCM800, JTM45 and others) it's what comes before the tone controls. Vb2 is the Cathode Follower.

Yeah, a cathode follower has no voltage gain, it doesn't boost, but it changes the output impedance to better drive the tone stack.
Some people mod the CF to a gain stage, to add gain to the amp. There are people who like and dislike this approach.

SteadyEddie wrote:

Haze13 wrote:CF - Cathode follower. In the Marshall schematics (Plexi, JCM800, JTM45 and others) it's what comes before the tone controls. Vb2 is the Cathode Follower.

Yeah, a cathode follower has no voltage gain, it doesn't boost, but it changes the output impedance to better drive the tone stack.
Some people mod the CF to a gain stage, to add gain to the amp. There are people who like and dislike this approach.

I gorcha! Do you loose the plexi tone if you make it a gain stage. Any time i change my 12 series to a 2203 preamp with a master volume it looses that plexi sound. Weird

Jeremy1283 wrote:

SteadyEddie wrote:

Haze13 wrote:CF - Cathode follower. In the Marshall schematics (Plexi, JCM800, JTM45 and others) it's what comes before the tone controls. Vb2 is the Cathode Follower.

Yeah, a cathode follower has no voltage gain, it doesn't boost, but it changes the output impedance to better drive the tone stack.
Some people mod the CF to a gain stage, to add gain to the amp. There are people who like and dislike this approach.

I gorcha! Do you loose the plexi tone if you make it a gain stage. Any time i change my 12 series to a 2203 preamp with a master volume it looses that plexi sound. Weird

I never tried the mod. Some hot-rodded plexi-type amps like Splawn and so on (If I'm not mistaken) do this. I'm sure some people will say yes, and some people say no.

Its a matter of taste.

Yeah this is for sure a Jackson mod.

That amp has 4 preamp valves, the fourth is obscured by all the floating components and is between the 2nd and third preamp tube.

The circuit is mostly his m1000 circuit, but has his attenuator circuit as well which is basically another form of ppmiv. (Found on the later ampeg amps)