Skip Navigation Website Accessibility
FX Pedals

Tsakalis Audioworks Room 40 Marshall Style Overdrive Pedal


  Over the years, we have had many different types of Marshall™ amps on our workbench, some for repairs and others for customization. Being huge fans of the sound of these classic amplifiers, that still continues to excite us through the music of so many artists, we decided to try and capture its mojo – the true essence of the soul of this sound – and carefully place it in a little box. Thus the Room #40 was born!
Using jfet technology, we tried to stay loyal to the tone and feel of the following legendary Marshall™ amps: the non master volume series PLEXI™ Super Lead (1959/1987) & Super Bass (1992) and the master volume series JMP™ & JCM800™ (2203/2204).
We emphasized on emulating the compression and sag coming from the power amp section, when these amps are pushed to the edge, while at the same time giving access to two famous mods, mod #39 (PLEXI™) and mod #34 (JMP™ & JCM800™). Of course the manifestation of our love for the late great Eddie Van Halen, who created the so called “brown sound” using an ohmite variac (variable transformer used to lower or raise the voltage going into the amplifier), could not be absent from this endeavor.
Finally, we incorporated the Presence control to make the sound adjustable to any circumstance, regardless of whether you are plugged into the front of an amp that may or may not have a bright cap or even straight to a power amp.


    • Handmade in Athens, Greece
    • True Bypass
    • 2 types of Marshall circuits PLEXI (19)/ JMP & JCM800 (22)
    • Variac voltage control from 7.5V to 21V
    • Classic Marshall™ 3 band EQ
    • Versatile Presence control for matching pedal to darker or brighter amps
    • Gain Boost controlled by a foot-switch and a dedicated trimmer
    • Power supply : 9V Boss-type DC adapter (center -). Using 10V or more may cause sever damage to the pedal and void the warranty
    • Max power consumption : 30mA @ 9V DC
    • Heavy duty & light weight aluminum box.  73mm(Width) x 123mm(Length) x 55mm(Height)
    • T.A.W. Limited Life-Time warranty