The Effectrode Delta-Trem is a tube stereo tremolo pedal from UK manufacturer Effectrode, a company that specializes in guitar pedals featuring vacuum tubes. Two 12AU7 tubes peak out of the right side of its case, and the tremolo effect itself is created with vacuum tubes and photo-resistors in a 100% tube signal path1.
At the heart of the circuit is a component Effectrode calls a "Raysistor", made up from a filament lamp and a photo-cell, used in conjunction with a vacuum tube signal path, twice over to give stereo operation. This is a modern take on the tube tremolo technology found in vintage tube amps, where the first instances of tremolo appeared, and which many guitarists still seek when they stomp on a tremolo pedal1.
Speed, Depth, Shape and Rhythm
The front panel carries four main controls, described by MusicRadar's reviewer Trevor Curwen and by Delicious Audio's Paolo De Gregorio:
| Control | What it does |
|---|---|
| Speed | Sets the tremolo rate, optionally controlled by a Tap Tempo footswitch2 |
| Depth | Sets the tremolo depth2 |
| Shape | In tap tempo mode, works as a tap divide/multiply control with eight different timing options; its main role is to morph through the 48 LFO waveforms stored in three banks of 16, selected via a rear panel toggle switch2 |
| Rhythm | Selects the waveform, including sine, triangle, square, pulse, rising and falling sawtooth, plus mixed waves between settings1 |
The Depth knob can also be configured as an independent L.F.O. control for amplitude modulation effects as the two channels drift in and out of phase, which opens up moving, stereo-modulating textures beyond a straight tremolo1.
Stereo and sound
In standard mode the signal is ping-ponged between the left and right outputs, so the tremolo sweeps across a stereo rig rather than pulsing both channels together1. Effectrode uses custom photo-cells to ensure absolute minimum harmonic distortion, which the maker says gives an exceptionally pure tremolo tone. De Gregorio describes the result as "an exceptionally warm and musical tremolo effect that blends well with clean and overdriven guitar sounds"1.
MusicRadar's verdict was in the same territory: "Lovely warm tremolo sound"2.
Power: 12V, 1.5A, and the build
The Delta-Trem runs on 12 volts DC at 1.5 amps, and it ships with a high quality low-noise switched-mode 12VDC at 1.5A wall-wart compatible with all of Effectrode's pedals1. That supply accepts 100V to 240VAC mains input and comes with different mains outlet adaptor plugs, so there is always a plug that fits the local outlet1.
MusicRadar's reviewer flagged that "12-volt/1.5-amp is not supported by many pedalboard power distributors"2. If you run a powered pedalboard, check whether your power supply offers a 12V outlet rated for 1.5A before adding the Delta-Trem, or plan to use the included wall-wart.
The build leans vintage as well as the circuit. The knobs are authentic phenolic Dakaware, Chicago 1510 knobs custom manufactured for Effectrode in the U.S.A using the original 1940s molds1.
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Questions
Does the Effectrode Delta-Trem have tap tempo?
Yes. The Speed knob sets the tremolo rate and can optionally be controlled by a Tap Tempo footswitch. In tap tempo mode the Shape knob works as a tap divide/multiply control with eight different timing options, so you can lock the tremolo to song tempo and choose how the taps relate to the LFO cycle.
Can the Delta-Trem run in stereo with ping-pong tremolo?
Yes. The Delta-Trem is a stereo pedal, and in its standard mode the signal is ping-ponged between the left and right outputs, so the tremolo effect alternates between the two channels rather than simply modulating both together.
What waveforms does the Delta-Trem offer?
The Rhythm knob selects the waveform, including sine, triangle, square, pulse, rising and falling sawtooth, plus mixed waves between settings. The Shape knob morphs through 48 LFO waveforms stored in three banks of 16, selected with a rear panel toggle switch.
Can I power the Delta-Trem from a standard 9V pedal supply?
No. The Delta-Trem runs on 12 volts DC at 1.5 amps, and MusicRadar's reviewer noted that 12-volt/1.5-amp is not supported by many pedalboard power distributors. The pedal ships with its own low-noise switched-mode 12VDC wall-wart, so plan your pedalboard power around it.
Does the Delta-Trem work with overdriven guitar tones?
Delicious Audio's Paolo De Gregorio described the effect as exceptionally warm and musical, blending well with clean and overdriven guitar sounds. MusicRadar's reviewer likewise called it a lovely warm tremolo sound.
Sources (2)
- Effectrode Delta-Trem Tube Stereo Tremolo, Delicious Audio, 2021-09-24
- Effectrode Delta-Trem review, MusicRadar, 2019-09-18