The MXR Power 50 Overdrive TBM1 is a signature overdrive pedal from MXR that captures the sound and functionality of Tom Morello's amp setup for use with any rig, from a simple combo amp to a high-end custom stack1. Morello has relied on that setup, a 50-watt Marshall JCM 800 2205 head through a Peavey 4x12 cabinet, for his signature distortion tones since 1988, and the Power 50 puts its preamp stages into a bright red pedal23.
In Morello's own words, quoted by Guitar World:
"The Power 50 Overdrive emulates the amp setup that I've used since 1988"34
Tom Morello, Guitar World4
MusicRadar notes that this is Morello's first ever signature overdrive pedal, and that the amp setup it emulates is the sound behind 21 studio albums3.
Tom Morello's amp setup in a pedal
For more than 30 years, the key component of Tom Morello's raw, hard-hitting sonic voice has been his amp setup, and the TBM1 is built to bring that to any pedalboard1. Delicious Audio describes it as "a bright red pedal that recreates Tom's amp set up and puts it at your toe tips," with "amp-like performance that's uncanny in its ability to reproduce those big, gnarly tones"2.
The circuitry uses MOSFET technology to recreate the preamp stages of Morello's amplifier, which MusicRadar identifies as his 50-watt Marshall JCM 800 2205 head through a Peavey 4x12 cabinet23. Because Morello relies solely on his amplifier for his signature distortion tones, the pedal is designed around that specific signal path rather than a generic overdrive circuit2.
The pedal works two ways. Delicious Audio reports it can be used as an amp in a box, run direct into a speaker emulator, or as an overdrive in front of your amp2.
The controls: six knobs from Tom's amp
The control panel mirrors an amp's front panel, with six knobs taken from the control interface of Morello's amp so you can replicate his exact settings: Gain, Bass, Middle, Treble, Volume and Presence2. MusicRadar likewise describes it as "mirroring amp controls with the Volume, Bass, Middle, Treble, Gain and Presence controls"3.
| Control | What it does | Spec |
|---|---|---|
| GAIN | Sets overdrive intensity | 1 |
| BASS | Cuts/boosts low frequencies of the pre-effects loop signal | +4 dB, -21 dB, 50 Hz1 |
| Mid | Cuts/boosts midrange | ±7 dB, 500 Hz1 |
| Treble | Cuts/boosts high frequencies | ±7 dB, 5 kHz1 |
| VOLUME | Controls overall volume of the pre-effects loop signal | 1 |
| PRESENCE | Adjusts high-end frequencies of the overall output signal | +7 dB, 4 kHz1 |
The manual lists the Treble control as +7 dB, -21 dB at 5 kHz1.
FX loop and output levels
The Power 50 includes an onboard effects loop with SEND and RETURN jacks for placing pedals after the pre-EQ signal1. The loop is configured just like it is on Morello's own amp, with the return placed before the EQ and Presence sections, and players can adjust its overall level23. Morello runs all his effects pedals through his amp's loop, and the TBM1 reproduces that arrangement3.
Setting up the loop follows the manual's instructions:
- Run a cable from the TBM1's SEND jack to the input of the first pedal in your loop1.
- Run a cable from the last pedal's output to the TBM1's RETURN jack, which breaks the effects loop connection and receives the effects loop output signal1.
The RETURN jack has a 1 MΩ impedance1. Output levels from the manual:
| Level | Value |
|---|---|
| Nominal output level | -12 dBV, all controls at mid position1 |
| Nominal send level | -26 dBV, all controls at mid position1 |
| Maximum output level | 0 dBV1 |
Powering it
The TBM1 runs on DC 9 volts1. Power it with a 9-volt AC adapter such as the Dunlop ECB003/ECB003EU, an MXR Brick Series power supply, or one 9-volt battery accessed through a battery door on the bottom plate1. The connector is 9V DC, center negative5.
Who uses it
The Power 50 Overdrive TBM1 is Tom Morello's signature pedal, his first ever signature overdrive with MXR34. Morello's distortion tones have come solely from his amplifier setup since 1988, and the pedal exists to put that setup in front of any player2.
Videos
Max Guitar Store
Algam EKO
Questions
Can the MXR Power 50 be used as an amp in a box?
Yes. Delicious Audio reports that the pedal can be used as an amp in a box, run direct into a speaker emulator, or as an overdrive in front of your amp. Its control panel mirrors a full amp preamp, with Gain, Bass, Middle, Treble, Volume and Presence knobs, plus an effects loop for placing other pedals after the pre-EQ signal.
Where does the FX loop return sit in the Power 50 circuit?
The effects loop return is placed before the EQ and Presence sections, configured the same way as on Tom Morello's own amp. That means pedals in the loop feed into the Presence stage rather than sitting at the end of the chain, and the loop has an adjustable overall level.
What power supply does the MXR TBM1 need?
It runs on 9V DC with a center negative connector. MXR specifies a 9-volt AC adapter such as the Dunlop ECB003/ECB003EU or an MXR Brick Series power supply, and it can also run on one 9-volt battery accessed through a door in the bottom plate.
Does the Power 50 use MOSFETs?
Yes. MusicRadar and Delicious Audio both report that the Power 50 Overdrive uses MOSFET technology to recreate the preamp stages of Tom Morello's amplifier, giving the pedal its amp-like response and character.
Sources (5)
- TBM1.pdf, Jim Dunlop, 2021
- MXR Power 50 Overdrive TBM1, Delicious Audio, 2022-12-05
- Tom Morello gets his first ever signature overdrive pedal with MXR POWER 50, MusicRadar, 2021-12-02
- MXR crams Tom Morello's iconic amp tones into a new signature pedal, the Power 50 Overdrive, Guitar World, 2021-12-02
- Power 50 TBM1 by MXR, RockBoard PedalPedia, 2026
Tom Morello
