The MXR TBM1 Tom Morello Power 50 Overdrive is a signature overdrive pedal from MXR that captures the sound and functionality of Tom Morello's amp setup for use with any rig1. Morello, the signature artist behind the design, got his first ever signature overdrive pedal with the Power 50, as MusicRadar reported when it launched2. Delicious Audio describes it as a bright red pedal that recreates Tom's amp setup and puts it at your toe tips, with amp-like performance that reproduces his big, gnarly tones3.
The pedal can be used two ways: as an amp in a box, running direct into a speaker emulator, or as an overdrive in front of your amp3. That flexibility is what separates it from a standard drive pedal: it carries a full amp-style control set and an onboard effects loop, not just gain and tone.
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, as the Jim Dunlop manual puts it, and the Power 50 Overdrive captures that setup in pedal form1. The control layout is taken directly from his amp's interface: Delicious Audio notes it features Gain, Bass, Middle, Treble, Volume and Presence knobs so you can replicate his exact settings3.
The part that makes it more than a clone of an amp's front panel is the effects loop. Morello runs all his effects pedals through his amp's loop, and MusicRadar notes that here players get an onboard effects loop running before the Presence control, with an adjustable overall level2. Delicious Audio adds that the loop is configured just like it is on Tom's amp, with the return placed before the EQ and Presence sections3.
The controls: EQ, Presence and the effects loop
The manual maps every control, and the signal order matters for how you use them. Volume, Bass, Middle and Treble all shape the pre-effects-loop signal, while Presence adjusts the high-end frequencies of the overall output signal. The loop return is placed before the EQ and Presence sections, configured like Tom Morello's amp13.
| Control | What it does | Spec |
|---|---|---|
| GAIN | Sets overdrive intensity | 1 |
| VOLUME | Controls overall volume of the pre-effects-loop signal | 1 |
| BASS | Cuts or boosts low frequencies of the pre-effects-loop signal | +4 dB, -21 dB at 50 Hz1 |
| MID | Midrange cut and boost | ±7 dB at 500 Hz1 |
| TREBLE | Treble cut and boost | ±7 dB at 5 kHz1 |
| PRESENCE | Adjusts high-end frequencies of the overall output signal | +7 dB at 4 kHz1 |
| FOOTSWITCH | Toggles effect on/bypass, red LED indicates on | 1 |
The manual lists the Presence control as +7 dB at 4 kHz1.
The loop jacks work like an amp's loop:
- SEND jack transmits the post-EQ signal to the effects loop1.
- RETURN jack feeds looped effects back in, ahead of the Presence control2.
- The loop's overall level is adjustable2.
The effects loop signal is only active while the TBM1 is engaged. With the pedal bypassed, nothing plugged into the loop passes signal1.
The manual gives one concrete recipe for the loop: if you have the TBM95 Cry Baby Tom Morello Wah, place it into the FX loop to recreate Tom's tonally balanced and aggressive vocal wah sweeps. The same manual notes the alternatives: before the TBM1 the wah produces a subtle effect, and after the TBM1 it creates a treble-focused, toe-down wah response1.
Power and connections
The TBM1 runs on DC 9 volts at 12 mA, with a center-negative 9V DC input14. Power options from the manual1:
- One 9-volt battery, accessible via a battery door on the bottom plate
- A 9-volt AC adapter such as the Dunlop ECB003 or ECB003EU
- An MXR Brick Series power supply
Output levels from the manual: nominal output level is -12 dBV with all controls at mid position, nominal send level is -26 dBV at the same setting, and maximum output level is 0 dBV1.
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Questions
Does the MXR TBM1 take a 9V battery?
Yes. The pedal runs on one 9-volt battery, accessible through a battery door on the bottom plate, according to the Jim Dunlop manual. It also accepts a 9-volt AC adapter such as the Dunlop ECB003 or ECB003EU, or an MXR Brick Series power supply. Current draw is 12 mA.
Is the MXR Power 50 true bypass?
Yes. The manual lists the bypass type as True Hardwire, so with the effect off the signal passes through without active processing. The footswitch toggles the effect on and off, and a red LED indicates when it is engaged.
Does the TBM1 effects loop work when the pedal is off?
No. The manual states plainly that the effects loop signal is only active while the TBM1 is engaged. Anything plugged into the loop only sounds when the pedal is on, so bypassing the pedal also takes the looped effects out of the chain.
What should I put in the TBM1 effects loop?
The manual's own example is the TBM95 Cry Baby Tom Morello Wah, which in the loop recreates Tom's tonally balanced and aggressive vocal wah sweeps. More generally, the loop suits the time-based and filter effects you would normally run through an amp's loop, since the return feeds into the EQ and Presence sections.
Why is the TBM1 return placed before the EQ?
Because it mirrors Tom Morello's actual amp. Delicious Audio reports that the loop is configured just like it is on his amp, with the return placed before the EQ and Presence sections, so looped effects get shaped by the pedal's tone controls on the way out.
Sources (4)
- TBM1.pdf, Jim Dunlop, 2021
- Tom Morello gets his first ever signature overdrive pedal with MXR POWER 50, MusicRadar, 2021-12-02
- MXR Power 50 Overdrive TBM1, Delicious Audio, 2022-12-05
- Power 50 TBM1 by MXR, RockBoard PedalPedia, 2026
