Rockstah Mod5 for Marshall head

Price Paid: 
$700 + $500 (mod)
Country of origin: 
Tube Type: 


After hearing many clips by of modded amps by Mark Abrahamian (aka Rockstah), I decided to try it myself. The mod works on single channel Marshalls, 100 or 50( 1959,1987,2203,2204) from late 60's all the way up to mid 80's. It doesn't work on multi channel amps, but it may work on other brands whith specs close to Marshall amps (i.e: Laney GL50). In any case, ask Mark.

I bought a 1987X RI from eBay in the US and had it send to Mark (in Texas). The mod costs $500 for parts and labor and took about a month for mine.

I don't know exactly what was done inside, but what was changed on my amp was:

1.the high and low jacks of the normal channel do not function anymore.

2. Only high and low of the bright inputs available.

3. Pots are changed and where they are set:

volume 2 - see this knob as how hard your guitar is hitting the first gain
stage. as well it adds to reduce bass if set lower.if you turn it down
past 7 it reduces bass or thickness.

volume 1 see this knob as how hard you are hitting the second gain stage.
master volume is added at the back of the amp.

Master volume (Post PI Master Volume = PPMV) at the back of the amp

Settings Mark used on demo clip :

volume 1: 8

volume 2: 8

treble on 9
middle on 9
bass  on 2
presence 8 but it doesn't really act as if it works when the master volume (PPIMV) is set below 6 or so. the higher the PPIMV is set the more the presence works.

ppimv-  on 1 . The lower this knob is set the less negative feedback we have the less the presence knob will seem to function.

Note: I picked an amp with Voltage selector 110V (US)-240V (Europe) so I could use it at home.


After the first try, I lower a bit volume 1 et 2 to 6 instead of 8 because I'm using a Music Man EVH which has (I think) more powerful pickups than on early EVH guitars.

At first i though the sound was great but not as good as Mark's demo clip

So I recorded myself through a 4x12 with Celestion Greenback Heritage speakers, using a simple SM57 and added some reverb in Cubase and voilà, I sounded almost like Eddie (minus the fingers...). 


Some controls are interdependants (see features). Only 2 inputs works with the mod.

The mod adds up to the price of the amp but you don't need any pedal, just plug and play.

Sound Quality: 
5 (excellent)

So good so far. But the headshell is broken and I noticed other amps of this model with the same issue.

Customer Support: 



It's a one trick pony but I stopped chasing one of the tone I was after for many years

Overall Rating: 
Average: 5 (1 vote)