The J. Rockett Audio Designs .45 Caliber Overdrive is an overdrive pedal built to put a vintage Marshall in front of your amp. J. Rockett describes it as "a recreation of the original 1962 JTM 45 sound, overdriven"1, and the company says the pedal was one players had been asking it to make for some time123. It was announced in June 2016 as the fourth release in the Tour Series line4.
The reference points are specific. According to the announcement, the sonic influence came directly from Malcolm Young's crunchy rhythm tones and Pete Townshend's Live at Leeds sound4, and MusicRadar reported that J. Rockett says it covers "crunchy tones from Malcolm Young to Pete Townshend Live At Leeds"5. In other words, this is a British-blues-breakup pedal, not a clean boost or a modern high-gain distortion.
A JTM45 amp in a box
The .45 Caliber belongs to the "amp in a box" family of drives: pedals that model the character of one specific amplifier rather than offering a general-purpose overdrive. Pedal of the Day called it "a recreation of the original 1962 Marshall JTM 45 sound" and said that "if you're on the hunt for your next amp-in-a-box pedal, this might be just what you're after"6. A 2016 guest review on the same site, from reviewer Daniel N., described it as "one beast of an OD pedal" based on "a 1962 plexi"7.
What that means in practice, according to reviewers, is a crunchy, compressed vintage-amp feel. MusicRadar's review team, testing the Tour Series version with a Gibson SG Jr "for a classic Townshend vibe," wrote854:
"It sounds like a great 60s valve amp, with a pleasing amount of compression when you dig in for lead stuff."8
The same review noted that while many overdrive pedals are happy to deliver generic dirt, "the .45 Caliber specifically aims to nail the classic Marshall 1962 JTM45 tone"8.
AC/DC and Townshend territory
The pedal's clearest reference point is AC/DC. Pedal of the Day called it "a dirt pedal derived from the classic rhythm playing of Malcolm Young"6, and Daniel N.'s guest review said it "strives to get that AC/DC sound (Malcom and Angus)"7. Rhythm crunch is the headline, but the same reviewer found it works for leads too: "It can just easily provide soaring lead tones that have a nice mid push"7.
For players comparing J. Rockett drives, the .45 Caliber sits apart from the company's Klon-style Archer and Archer Select or its Dumble-inspired The Dude: those chase other amps entirely, where the .45 Caliber is pointed at one 1962 Marshall386.
The controls and Speed Switch
The control set is simple and amp-like, four knobs named the way a JTM45's panels are4:
| Control | What it does |
|---|---|
| Loud | Output volume |
| Gain | Amount of overdrive |
| Bass | Low-end response |
| Treble | High-end response |
The pedal also introduced J. Rockett's new Speed Switch footswitching system, which MusicRadar highlighted at launch5 and Premier Guitar confirmed the pedal "takes advantage of"4. Pedal of the Day's 2022 review, which covered the pedal over a year in the making, praised the hardware as well: "The sturdy shell and excellent build ensure that this pedal will be in your rig for years and years to come"6.
Power, size and placement
The .45 Caliber runs on 9V DC with a standard negative-tip, positive-sleeve plug, the same arrangement as most modern pedals, so it fits a typical pedalboard supply6. The input and output jacks sit at the head of the pedal, and at approximately 4 by 2.30 inches it occupies a small footprint4. At launch it carried a $189.00 street price4, also reported by Guitar.com3.
The negative-tip, positive-sleeve power requirement means the pedal needs a correctly wired 9V DC supply; an adapter with reversed polarity will not work.
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Questions
Is the J. Rockett .45 Caliber good for AC/DC tones?
Yes, that is the pedal's stated aim. J. Rockett says its sonic influence came directly from Malcolm Young's crunchy rhythm tones, and reviewers describe it as a dirt pedal that strives for the AC/DC sound of Malcolm and Angus Young. It also covers Pete Townshend's Live at Leeds territory and can push soaring lead tones with a mid boost.
What power does the J. Rockett .45 Caliber take?
It runs on 9V DC with a standard center-negative arrangement: negative tip and positive sleeve. That means it works with a typical 9V pedalboard power supply, and the polarity rules out adapters wired the other way around.
Where are the jacks on the .45 Caliber Overdrive?
The input and output jacks sit at the head of the pedal, the end facing away from you as you operate the footswitches. The pedal measures approximately 4 by 2.30 inches, so it takes up little board space.
Is the .45 Caliber part of the J. Rockett Tour Series?
Yes. Premier Guitar reported it as the fourth product release of the Tour Series line when it was announced in June 2016, and MusicRadar's later review covers it under the Tour Series .45 Caliber name.
Sources (8)
- .45 Caliber Overdrive, rockettpedals.com, 2025-09-28
- .45 Caliber Overdrive, rockettpedals.com, 2026-04-01
- Summer NAMM2016: J. Rockett Audio Designs debuts new .45 Caliber Overdrive pedal, Guitar.com, 2016-06-20
- J. Rockett Launches .45 Caliber Overdrive Pedal, Premier Guitar, 2016-07-13
- J Rockett Audio Designs takes aim with .45 Caliber Overdrive guitar effects pedal, MusicRadar, 2016-06-16
- J. Rockett Audio Designs .45 Caliber Overdrive, Pedal of the Day, 2022-09-14
- Guest Reviewer Fridays: J.Rockett .45 Caliber Overdrive, Pedal of the Day, 2016-11-18
- J Rockett Audio Designs Tour Series .45 Caliber review, MusicRadar, 2016-07-28
