The Supro 1310 Tremolo is a tremolo pedal designed to recreate two different types of tremolo effect found in American amplifiers of the 1960s: the conventional amplitude style and the rarer harmonic style. It first appeared as the 1310 Harmonic Tremolo, which Supro launched in December 2016 as a vintage-styled pedal offering sounds based on the warm, classic tremolo effect you would normally associate with a vintage valve amp12. It sits in the maker's pedal range alongside the related Supro Dual Mode Tremolo and Supro Analog Dual Mode Tremolo, and belongs to the wider family of tremolo pedals.
Two amp-style tremolos in one box
The pedal's central feature is a large toggle switch that selects between Amplitude mode and Harmonic mode. Amplitude mode offers the conventional tremolo sounds typically generated by bias-modulating an amp's power valves, the pulsing volume wobble most players know from vintage amplifiers. Harmonic mode apes the more phase-y tremolo associated mainly with Fender 'brownface' amps, where the tremolo works on the balance of frequency bands rather than raw volume2.
MusicRadar's reviewer Trevor Curwen found that both modes sound excellent: "the Amplitude trem has a classic pulse and throb, while Harmonic has that extra hint of pitch change"2.
Controls
The layout is deliberately simple, with three knobs and the mode toggle1:
| Control | What it does |
|---|---|
| Speed | Dials in the rate of the trem effect, with the extra option of adjusting speed via an expression pedal2 |
| Depth | Sets the intensity of the trem effect2 |
| Gain | Does not turn up the output volume as such, but sets the amount of preamp gain in the pedal, offering various degrees of overdriven texture to the trem2 |
| Mode toggle | Selects between Amplitude and Harmonic modes, each giving a different tremolo sound21 |
The expression input is worth flagging for players who use their feet: an optional external expression pedal can control the speed of the tremolo effect1, so the rate can be swept live rather than fixed by the knob.
The Gain knob is a preamp gain control, not a level control. It adds overdriven texture to the tremolo rather than boosting output volume2.
Gain and the Class A circuit
The extra tonal mojo comes via the Gain knob, which sets the level of preamp gain and adds overdriven texture on top of the tremolo, as Guitar World's review of the design describes it3. According to Supro's marketing, the pedal emulates a Class A circuit "from end to end"1, the kind of circuit associated with vintage valve amplifiers. gearnews.com's reviewer picked up on Supro's own "swampy" description of the tone and found it seemed to suit the sound: warm with a subtle warble, not too choppy, bordering on a very organic amp-like feel1.
Players who want more of that overdriven character in other forms can look at overdrive pedals as a separate gain stage, but the 1310 keeps it inside the tremolo pedal itself23.
What reviewers said
MusicRadar's verdict, from Trevor Curwen, was that the pedal puts "two classic US amp-style trems in one pedal with optional valve-like grit"2. Among the points in its favor, he counted the Gain knob as superb, and concluded there were very few reasons to avoid it2.
Videos
Pete Thorn
Supro
PJ and the Beard
Questions
Can you control the Supro 1310 Tremolo speed with an expression pedal?
Yes. Alongside the standard Depth and Speed knobs, the pedal has the option of adjusting speed via an expression pedal, as MusicRadar's reviewer noted. An optional external expression pedal plugged in can control the speed of the tremolo effect, which lets a player sweep the rate of the wobble during a song without bending down to turn a knob.
What is the difference between amplitude and harmonic tremolo?
Amplitude mode offers the conventional tremolo sounds typically generated by bias-modulating an amp's power valves, giving a classic pulse and throb in the guitar's overall volume. Harmonic mode apes the more phase-y tremolo associated mainly with Fender 'brownface' amps, and MusicRadar's reviewer found it carries that extra hint of pitch change.
Does the Supro tremolo pedal add overdrive?
It can. The Gain knob does not turn up the output volume as such, but sets the amount of preamp gain in the pedal, offering various degrees of overdriven texture to the tremolo. Supro's marketing also says the pedal emulates a Class A circuit from end to end, and MusicRadar described the result as optional valve-like grit.
What did reviewers think of the Supro 1310 Tremolo?
MusicRadar's Trevor Curwen summed it up as two classic US amp-style trems in one pedal with optional valve-like grit, and found both trem modes sound excellent, with the Amplitude trem having a classic pulse and throb while Harmonic has that extra hint of pitch change. He called the Gain knob superb and saw very few reasons to avoid it. gearnews.com gave it a 4.0 out of 5.0 rating.
Sources (3)
- Supro 1310 Harmonic Tremolo: Swamp Thing?, gearnews.com, 2016-12-06
- Supro 1310 Tremolo review, MusicRadar, 2017-07-02
- Hamstead Soundworks Signature Analogue Tremolo MKII review, Guitar World, 2021-02-10
