Randall MTS Series Module SL+ to JCM800 Modification
Convert SL+ to JCM800
One of the great things about the Randall MTS series is the ability to customize your tone to
exactly how you want. This includes modifying your modules to get the sound perfect for your
In this article we will cover modifying your Randall SL+ to a JCM800. Check back often
as new mods are become available this article will be updated.
Marshall Tone Stack Mod
The current Randall SL+ as well as the original single channel Egnaters have the original Marshall mid circuit with less mid-range than the JCM800 amps. The older
Marshall circuits don't have less sizzle or distortion just less mid-range which makes that sizzle or distortion more apparent. You can adjust the mid range circuit
with 2 small part changes to make it more like the newer (JCM800) Marshall tone controls. To change to the new
Marshall circuit you would have to change R31 to a 33K resistor and C14 to a 470pf (500V min). This would add more cutting mid-range with still about the same level of
cut when the mid knob is lower.
Check the original Modification article for PCB board layouts.