Anasounds Trémolo

The Anasounds Trémolo is an optical tremolo pedal made in France by Anasounds, released at NAMM 2020 as the second pedal in the company's FX Teacher series¹². It is an unusual hybrid: the guitar signal never passes through an analog-to-digital converter, but a processor generates the LFO waveforms that drive the optical circuit doing the actual amplitude modulation¹².

Anasounds describes the result as "a highly flexible and evolving tremolo that still keeps the big warm sound of optical technology"³. The pedal was previously known as the Sliver before being introduced as the TREMOLO in 2021⁴.

An optical-style tremolo with a digital brain

Optical tremolos work by using a light-dependent element to vary the signal's amplitude, the same principle as the photocell tremolo circuits built into vintage amplifiers. In the Trémolo, the analog audio path runs through the optical circuit, while the waveforms that pulse it are created digitally. As the maker puts it:

Anasounds is explicit that the audio itself stays analog: "You won't find an analog to digital converter in there, your sound only goes through a purely analog signal path"¹. The pedal offers six waveform presets, including sinus, saw and square, selectable via a switch in the center of the pedal¹. Delicious Audio's writeup described it as "an optical tremolo with sinus, triangle and square LFO options that can also be purchased in a DIY kit"⁴.

The maker's own technical analysis explains how the optical stage behaves: with the LFO at 1 the LED lights up, the impedance at that stage is 440 Ohms and the gain is -5.7, increasing the volume; with the LFO at 0 the LED turns off, the impedance is 5 MOhms and the gain is -33 dB, muting the sound⁵.

The controls

The Trémolo has all the classic tremolo controls except one: there is no rate knob, because the rate is set entirely through the Tap Tempo footswitch⁴. That footswitch also carries killswitch functionality, in both momentary and Killswitch mode⁴.

The Trimpot mode is a hidden second layer of controls, a scheme Anasounds also used on its Ages harmonic tremolo, where the Tone control becomes an Attack detector in the same mode⁷. For players with what the maker calls "an extremely precise rhythmic ear," FREE_SUBDIVISION allows a custom time division rather than a fixed one⁶.

Two boards, kit and assembled versions

Internally, the Trémolo is built on two printed circuit boards: a motherboard and a daughterboard. The daughterboard handles the analog signal processing, while the motherboard handles the power supplies and the digital signals, including generating the LFO². An ATMEGA328 microcontroller on the motherboard drives the relay used for the true bypass switching, and the two footswitches are simple contactors that send information to that microcontroller².

The pedal is sold in two forms:

• Assembled version: ready to play, listed at 199,00 €¹⁵
• Kit version: the same pedal as a DIY build, listed at 149,00 €, with internal trimpots to adjust the bias and output level³⁵

The kit is part of the FX Teacher series, which the manual walks builders through step by step². The kit version keeps the same optical circuit and the same set of features as the assembled pedal³.

The Spinner and external control

On the back of the pedal there is an additional stereo mini jack that accepts the Anasounds Spinner expression pedal or an external tap tempo source such as the Anasounds Tap⁶⁸. Anasounds says the Spinner idea came directly out of the work on the Trémolo, "looking for ways to make the simple tremolo effect more lively"⁸. Plugging the Spinner in gives what the maker calls a large range of additional variations controlled by the speed of your foot¹.

Guitar World's reviewer, writing about the pedal in its earlier Sliver form, found that it "really steps up a notch" with the Spinner, "capable of a beautifully expressive shimmer effect that interacts with your music overall"⁹.

Questions