The Supro Dual Mode Tremolo is a tremolo pedal that sets out to recreate the sound of a 1960s amp tremolo circuit inside a stompbox. It is all-analog, and it offers two kinds of modulation: Amplitude, the classic level-based tremolo, and Harmonic, the more complex circuit found in some vintage US amplifiers. Delicious Audio's Paolo De Gregorio describes it as "delivering a tremolo effect with the harmonic character of the ones you'll find inside guitar amps of the '60s"1.
Amplitude and harmonic tremolo with an output transformer
What makes this pedal unusual among tremolo pedals is that it models an amplifier's signal path rather than simply modulating the signal's level. According to Delicious Audio, it has pre-amp and power amp sections, "with an actual output transformer deployed to recreate" the magnetic saturation and coloration of original vacuum tube-based effects1. Pedal of the Day's review of the earlier Analog Dual Mode Tremolo describes the same architecture: preamp and power amp sections, including an actual output transformer, used to recreate the magnetic saturation characteristic of historic Supro amps2.
The two modes behave differently. Amplitude is the swampy, level-based tremolo most players know from vintage amps; Harmonic modulates in the more complex way of certain 1960s circuits, which Pedal of the Day describes as "psychedelic modulating tones"2. The pedal is a direct relation of the Supro 1310 Harmonic Tremolo and the Supro Analog Dual Mode Tremolo, the earlier version of this same design23.
The controls: Speed, Depth, Gain and Mode
The pedal has four controls, listed by Guitar Pedal X as "Depth, Gain, Speed, and Mode: Amplitude/Harmonic"3.
| Control | What it does |
|---|---|
| Speed | Sets the rate of modulation; with an expression pedal connected, it sets the maximum value1 |
| Depth | Sets the amount of modulation1 |
| Gain | Sets the amount of "preamp" gain in the pedal1 |
| Mode | Selects Amplitude or Harmonic tremolo3 |
The Speed and Depth controls "determine the rate and amount of modulation present in the effect," according to Delicious Audio1. The Gain control is where the amp-like character comes in: as you turn it up, the "power amp" circuit is pushed into overdrive, with magnetic saturation occurring, and the output level is automatically compensated to maintain a consistent signal level. Delicious Audio says this gives "a wide range of sounds from clean to grind"1. Pedal of the Day likewise notes a Gain control with automatic output level compensation2.
An industry-standard TRS expression pedal can be used to control the speed. When an expression pedal is in use, the on-board Speed knob sets the maximum value, so foot control sweeps the rate up to that ceiling rather than across the knob's full range1. Pedal of the Day describes this as an assignable expression pedal control for the Speed function2.
What changed on the restyled version
In January 2024, Supro refreshed the Dual Mode Tremolo's looks without changing the circuit. Guitar Pedal X reported that the pedal received "a smoother, more modern enclosure and milled aluminium" knobs, replacing the earlier brushed finish and stylised silver-top knobs3.
The 2024 re-styling removed the easy-access battery compartment. Guitar Pedal X noted that "The battery option remains on the Drive pedal," so the Dual Mode Tremolo itself runs from an external power supply3.
What reviewers said
Pedal of the Day, reviewing the Analog Dual Mode Tremolo in collaboration with Sweetwater, called it "the absolute most authentic tremolo effect ever offered in pedal form" and said that "it sounds amazing, taking you on a modulated journey into the unknown"2.
Guitar Pedal X's Stefan Karlsson, covering the 2024 re-styling, found the signature tone intact and described the pedal as a long-standing player favorite in its field: "It remains a simple, intuitive, highly regarded Harmonic Tremolo"3.
Videos
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Phillip McKnight
60 Cycle Hum
Questions
Does the Supro Dual Mode Tremolo take a battery?
No. When Supro refreshed and re-styled the Dual Mode Tremolo in 2024, the easy-access battery compartment was removed. Guitar Pedal X noted that the battery option remains only on Supro's Drive pedal, so the Dual Mode Tremolo runs from an external power supply.
Can you control the Supro tremolo speed with an expression pedal?
Yes. An industry-standard TRS expression pedal can be used to control the speed of the tremolo. When an expression pedal is connected, the on-board Speed knob sets the maximum value the pedal can reach, so you can sweep the rate up to that ceiling with your foot.
What is the difference between harmonic and amplitude tremolo?
Amplitude tremolo varies the overall loudness of the signal, the swampy effect found in many 1960s amplifiers. Harmonic tremolo varies the balance of frequency bands rather than just the level, giving a more complex, psychedelic modulation. The Supro pedal offers both, selected with its Mode control.
How much does the Supro Dual Mode Tremolo cost?
At the time of the 2024 re-styling, the pedal was listed at $219 from the Supro Webstore, with international dealers described as imminent by Guitar Pedal X.
What changed on the restyled Supro Dual Mode Tremolo?
The 2024 refresh gave the pedal a smoother, more modern enclosure with milled aluminium knobs, replacing the earlier brushed finish and stylised silver-top knobs. Guitar Pedal X reported that the signature tone was intact, and the easy-access battery compartment was removed.
Sources (3)
- Supro Dual Mode Tremolo, Delicious Audio, 2025-01-17
- Supro Analog Dual Mode Tremolo, Pedal of the Day, 2023-11-19
- Guitar Pedal X, Guitar Pedal X, 2024-01-16
