Please could someone tell me what differentiates this model from the other Plexi replicas?

anybody else own this amp that can do a review about it?

Filtering is lowered to 32x32 cans which was more like Ed's 68 Plexi. 100pf cap on the phase inverter section istead of the 47pf. .1uf coupling caps in that section as well, instead of the 0.022's. Ed's amp had 820k Carbon Comp resistors at V1 and V1B which had drifted in value to 1K, that's what is in the Brown amp, and V1 Cathode .68 cap changed to 330uf like what wa found in Ed's amp. here's where the info was found for making this amp. I think Nik was trying to create this version. Ceriatones Super Lead is based on the 69 Circuit where as Ed's amp was a 67/68 which is different from a 69.

1) By Mark Cameron by pictures taken in the early 80'S.
There ARE small tone altering and/or gain altering mods.

...the cap on v2(330uf) cathode.
...its a 2.7k/.68 and the resistor looks like the stock part(but I don't think it is)but the cap is one of those yellow square type from the 70' Marshall's. From the circuit card It looks like it came stock with this arrangement. The post that is pressed in looks stock too witch tells me more than anyone could.In the pics the serial # is 12301.


(2) By ******. 1980.
To try to wrap up is ED thing...
His head was a 67/68 and he had the first stage valve with BOTH cathodes tied together sharing the same 820 ohm resistor that was bypassed with a 330uF blue cap...

His treble cap was a round shaped ceramic that was a 250pF that said MURATA ... With 56K on the tone circuit feed..

One of the 470K mixer resistors was bypassed with a round hollow tubular MURATA cap 500pF... If memory serves me right on the value, or it was a 330pF..I will check my notes....

The real kicker, his phase-inverter "get-rid-of-the-FIZZIES" cap was a 100pF instead of the normal 47pF ....and this my friends is how the "brown sound" with that added compression happens..

Oh, BTW those 820 ohm resistors were carbon-comp and drifted in value up about 1.1K and make the amp much more gainy and warmer, since these re-bias the 12AX7 valves in a bit more non-linear region..

I am pretty sure the feedback resistor was a 47K ...I will have to check my notes...

The filter cap in the center of the board was a dual 16uF gray RS cap...

The screen filtering was 2 DALY 32uF light-blue caps in series... The voltage doubler were 2 100uF DALY royal-blue caps...

Rear cap on top of chassis was a royal-blue HUNTS 32uF or 16uF...need to check notes..

The value of the coupling cap between V1 and V2a....022uF.

At least that was what it was in 1980...

I have some clips here:
http://www.soundclick.com/bands/default.cfm?bandID=682660&content=music

Look for the EVH Tests and anything with the Load Box should be the Plexi Brown 100.  They aren't the greatest playing and I'm not that great at recording, either.  But it will give you an idea of what the amp sounds like.  It's a great amp and sounds better live than I can ever record it.

BTW, my PB100 has the split cathodes and a PPIMV installed.  Great amp!

Anybody else use transformers from Magnetic Components?   Their name has popped up several times this year.