The MXR Power 50 TBM1 is a Tom Morello signature overdrive pedal from MXR, a bright red pedal that recreates Tom Morello's amp setup and puts it at your feet1. MusicRadar reported it as Morello's first ever signature overdrive pedal2. RockBoard's PedalPedia describes it as capturing "the sound and functionality of that setup for use with any rig, whether you have a simple combo amp or a high-end custom stack"3.
What sets it apart from a typical overdrive is that it behaves like a small amp head rather than a simple gain stage. It carries a full control set taken from the amp's interface, plus an effects loop wired the way Morello's amp is wired. Delicious Audio notes it can be used as an amp in a box direct into a speaker emulator, or as an overdrive in front of your amp1.
A Tom Morello Power 50 amp setup in a pedal
The TBM1's control panel mirrors the front panel of Morello's amp: Gain, Bass, Middle, Treble, Volume and Presence knobs, so you can replicate his exact settings1. Under the hood, the signal path is arranged like the amp's, with an effects loop whose return sits before the EQ and Presence sections1.
The loop is the feature that makes the pedal work like an amp head. The manual instructs: "If using the effects loop, run a cable from the TBM1's SEND jack to the input of the first pedal in your loop"4. Pedals placed in the loop land after the gain stage but before the tone shaping, which is where time-based effects such as delay sit in a conventional amp's loop.
| Control | What it does | Range and frequency |
|---|---|---|
| Gain | Sets overdrive intensity | 4 |
| Treble | Cuts or boosts high frequencies of the pre-effects-loop signal | ±7 dB at 5 kHz4 |
| Mid | Cuts or boosts midrange | ±7 dB at 500 Hz4 |
| Bass | Cuts or boosts low end | +4 dB, -21 dB at 50 Hz4 |
| Presence | Adjusts high-end frequencies of the overall output signal | +7 dB at 4 kHz4 |
| Volume | Sets output level | 1 |
Note the split between Treble and Presence: Treble shapes the signal before the effects loop, while Presence shapes the high end of the overall output, after the loop return4. That division is what lets the pedal behave like an amp with a loop rather than a pedal with a flat tone stack.
The manual also lists a second Treble specification of +7 dB, -21 dB at 5 kHz alongside the ±7 dB figure, so the two entries in the same document disagree on the cut depth4.
Input and output impedance
The manual gives a full set of connection specifications4:
| Connection | Impedance | Level |
|---|---|---|
| Input | 700 kΩ | |
| Output | 900 kΩ | Nominal -12 dBV, maximum 0 dBV (all controls at mid position for nominal) |
| Send | 10 kΩ | Nominal -26 dBV (all controls at mid position) |
| Return | 1 MΩ |
For a player, the numbers that matter most are the input and return impedances. A 700 kΩ input and a 1 MΩ loop return are high enough that most guitars and pedals drive them without loading down or losing top end. The 900 kΩ output impedance is unusually high for a pedal, so long cable runs after it, or a low-impedance input on the next device, are worth thinking about when you wire a board around it4.
Analog MOSFET circuit, two ways to use it
The Power 50 TBM1 is an analog overdrive3, and MusicRadar reported that MXR opted for MOSFET technology for the circuit2. MOSFET clipping is a design choice often used where a pedal is meant to respond like an amp rather than a stompbox.
Because the pedal carries a full preamp-style EQ and an effects loop, Delicious Audio describes two working modes: as an amp in a box feeding a speaker emulator directly, or as an overdrive placed in front of your amp1. In the first role it replaces a head; in the second it drives the front end of whatever amp you already own.
MXR's overdrive range includes several other signature and amp-style designs, among them the MXR GT-OD, the MXR Dookie Drive and the MXR FOD Drive, but the TBM1 is the one built around a single player's complete amp setup rather than a general-purpose circuit.
Powering it
The pedal runs on DC 9 volts and draws 12 mA4. RockBoard's PedalPedia listing specifies a 9V DC center negative supply3. The manual recommends a 9-volt AC adapter such as the Dunlop ECB003 or ECB003EU, or an MXR Brick Series power supply, and the pedal also takes one 9-volt battery through a door on the bottom plate4.
The 12 mA draw is low enough that the TBM1 shares easily with other pedals on a multi-output supply, but the center negative polarity is the standard Boss-style convention: check any adapter you already own before plugging it in.
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Questions
Is the MXR Power 50 TBM1 a Tom Morello pedal?
Yes. The TBM1 is Tom Morello's signature overdrive pedal with MXR, and MusicRadar reported it as his first ever signature overdrive. It is built to recreate the sound and functionality of his Power 50 amp setup, with Gain, Bass, Middle, Treble, Volume and Presence controls mirroring the amp's interface so players can replicate his settings.
What power supply does the MXR TBM1 need?
It runs on DC 9 volts, drawing 12 mA, from a 9V DC center negative supply. Jim Dunlop's manual recommends a 9-volt AC adapter such as the Dunlop ECB003 or ECB003EU, or an MXR Brick Series power supply. It can also run on one 9-volt battery, accessible through a battery door on the bottom plate.
Is the MXR Power 50 Overdrive analog or digital?
It is an analog overdrive pedal. MusicRadar reported that MXR used MOSFET technology for the circuit, and RockBoard's PedalPedia listing for the Power 50 TBM1 lists the circuit type as analog. MOSFET clipping is often associated with a smooth, amp-like overdrive character.
Where can I download the MXR TBM1 manual?
The manual is published by Jim Dunlop as a PDF at jimdunlop.com/content/manuals/TBM1.pdf. It covers the controls, the effects loop wiring, power options and the full specification table, including input and output impedances and nominal and maximum output levels.
Sources (4)
- 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
- Power 50 TBM1 by MXR, RockBoard PedalPedia, 2026
- TBM1.pdf, Jim Dunlop, 2021
