ARHIV

🛬 Comming soon 🔜 ARHIV is the compact but powerful CV Recorder / Player. It can record up to 70 minutes ! modulation whether from the incommung CV input or the mouvement of the knob! Both are monitored in real-time on CV out ! ✅

Your last record is automatically stored in memory 🧠 and you’ll find it even after power cycling your rack✅

The output can be uni or bipolar✅

Play can be One Shot or Looping - started manually or by trigger.

In Playback mode the knob allows to control the Playback Speed: slowed down from X0.25 to X1, accelerated from X1 up to X4 and Reverse ✅

Playback speed is CV contrôlable if CV IN present while Play ✅

Beside trigger there is also a Gate dependent playback mode: Gate high-Loop, Gate low-Hold ✅

It can record the Clock ⏰ in paralel with your CV (Sequence stepped Mode) so your CV is syncronized - that way, when in Playback using the clock, every tick of the clock will advance one step forward your sequence as when recorded ✅

À very powerful little tool!

2hp, 33mm deep

Power specs: +12V 60mA, -12V 10mA, no 5V required

Currently in production, will be available by the and of the month of April '26

CV Recorder — User Manual

What is it?

The CV Recorder is a Eurorack module that records control voltages (CV) and plays them back on loop or on demand. Think of it as a tape recorder, but instead of recording sound, it records movement — the rotation of a potentiometer, the shape of an LFO, the curve of an envelope, or any other control voltage present in your modular system. Once recorded, that voltage can be played back at will, at different speeds, on loop or as a single pass, and even in reverse.

It's a powerful creative tool: you can capture a unique hand gesture on a potentiometer and turn it into repeatable modulation. You can also record the output of a sequencer and play it back at a different tempo, or use the module as a step sequencer by recording with an external clock signal.

The recording is stored in flash memory and survives power cycles. When you turn your modular back on, the last recording is automatically reloaded and ready to play.

Controls

The module has two buttons, a potentiometer, two switches, and three jacks.

The REC button starts and stops recording. A short press begins recording, a second short press stops it. During recording, the LED blinks red. Everything the module captures is simultaneously sent to the CV OUT jack, allowing you to hear or see in real time what you are recording. This is very handy for adjusting a potentiometer movement while listening to its effect on an oscillator or filter.

The PLAY button has two functions depending on how long you hold it. A short press (less than one second) starts or stops playback. The LED lights up solid green during playback. A long press (more than one second) toggles between the module's two playback modes: LOOP and ONE-SHOT. When you change modes, the LED flashes three times to confirm: three green flashes mean you are in LOOP mode, three red flashes mean you are in ONE-SHOT mode. By default, the module starts in LOOP mode.

The potentiometer (KNOB) serves two different roles depending on what the module is doing. During recording, if the source switch is set to KNOB, the potentiometer is the signal source being recorded — its position is what gets captured. During playback, the potentiometer controls the speed at which the recording plays back. Over the first part of its travel (roughly 0 to 40%), playback goes from very slow (0.25× normal speed) to normal speed. From 40% to 85%, playback accelerates up to 4× normal speed. Beyond 85%, playback switches to reverse, starting fast and then slowing down. Any CV signal connected to CV IN is added to the potentiometer value for speed control — the knob becomes a base setting and the CV adds movement on top.

The source switch selects the recording source. In the KNOB position, the potentiometer is recorded. In the CV EXT position, the signal present on the CV IN jack is captured.

The output range switch selects between unipolar and bipolar output. In the unipolar position, the CV OUT jack outputs voltages in the 0V to +5V range. In the bipolar position, the output swings from approximately −5V to +5V. Bipolar mode is essential when recording signals that cross zero volts, such as bipolar LFOs, audio-rate modulation, or any CV source that goes negative. In unipolar mode, the negative portion of such signals would be clipped at 0V, effectively losing half the waveform — a triangle LFO, for example, would come back as a shape with a flat bottom instead of a smooth symmetrical wave. Unipolar mode is best suited for signals that are naturally positive, such as envelopes, gate signals, or pitch CV from sequencers.

The CV IN jack is the input for an external control signal you want to record (LFO, envelope, sequencer output, etc.). This signal is conditioned by an analog circuit before being digitized. During playback, CV IN is added to the potentiometer to modulate playback speed.

The CV OUT jack is the module's output. During recording, it mirrors in real time what is being captured (monitoring). During playback, it reproduces the recorded signal. The voltage range depends on the output range switch position.

The TRIG / CLK jack accepts trigger or clock signals. Its behavior depends on the mode the module is in, which is explained in detail in the following section.

The two operating modes

The CV Recorder offers two fundamentally different operating modes, each suited to a distinct use case. You toggle between them with a long press on PLAY.

LOOP mode — the continuous recorder

LOOP mode is the default mode. It is the most intuitive: it faithfully and continuously records everything that happens, then plays it back on loop.

During recording in LOOP mode, the module captures 500 samples per second. This is fast enough to faithfully reproduce any potentiometer movement or LFO waveform without perceptible quality loss. The TRIG input is ignored during recording in LOOP mode — the module always records at a constant rate regardless of what arrives on that input.

During playback in LOOP mode, the recording loops endlessly. The potentiometer controls the speed. If a signal is connected to the TRIG jack, it acts as a gate: as long as the signal is high (active), playback runs. When the signal drops low (inactive), playback freezes on the last value and the output stays steady. This is very useful for synchronizing the start and stop of modulation with other elements of your patch.

LOOP mode is ideal for capturing complex LFOs, expressive potentiometer movements, long envelopes, or any continuous modulation you want to loop.

ONE-SHOT mode — the sequencer

ONE-SHOT mode turns the CV Recorder into a step sequencer. It is a more rhythmic and structured mode, designed to be synchronized to an external clock.

During recording in ONE-SHOT mode, the module listens to the TRIG input. If clock pulses arrive on this input, the module automatically switches to clocked recording: instead of capturing 500 samples per second, it captures a single sample on each clock pulse. The potentiometer position (or the voltage on CV IN) at the precise moment of each pulse is stored as a sequence "step." If no clock is detected, the module records continuously at 500 Hz, exactly like LOOP mode. Clock detection is automatic and robust: three consecutive pulses are required before the module confirms the presence of a clock, preventing random noise from accidentally triggering clocked mode.

In ONE-SHOT mode, recording is synchronized to the clock grid. When you press REC, the module arms itself — the LED turns solid red — and waits for the first clock pulse to actually begin recording. Similarly, when you press REC again to stop, the module waits for one last clock pulse, captures that final step, and then stops. This ensures the recording is perfectly aligned to the clock with no extra samples at the beginning or end. If you change your mind while the module is armed, simply press REC again before any clock pulse arrives to disarm.

After a clocked recording, you do not need to press PLAY to start playback. Simply leave the clock running: the module will automatically enter step mode on the next incoming pulse and begin stepping through the sequence. The sequence loops back to the beginning when it reaches the end, so as long as the clock keeps running, playback continues indefinitely. Pressing PLAY would start continuous (non-clocked) playback instead, which is a different behavior.

During playback in ONE-SHOT mode without a clock, a short press on PLAY starts playback once from beginning to end, then the module stops. The potentiometer controls the playback speed.

During playback in ONE-SHOT mode with a clock, the module works as a sequencer: each pulse on the TRIG input advances the sequence by one step. Between pulses, the output holds steady at the last value (sample-and-hold behavior). When the sequence reaches the end, it automatically wraps back to the beginning. The green LED blinks slowly to indicate that step mode is active. A short press on PLAY returns to continuous playback.

Clocked ONE-SHOT mode is perfect for creating melodic sequences by turning the potentiometer while the clock runs. It is also the right mode for recording the output of an external sequencer and playing it back in a synchronized manner.

Usage examples

Capturing a potentiometer gesture

Set the module to LOOP mode (long press on PLAY, three green flashes). Set the source switch to KNOB. Press REC, turn the potentiometer to create your movement, then press REC again to stop. Press PLAY to hear your gesture looping. Connect CV OUT to the CV input of a filter or oscillator to hear the effect of your movement repeated endlessly.

Recording an LFO and transforming it

Set the source switch to CV EXT and the output range switch to bipolar if your LFO crosses zero volts. Connect the output of an LFO to CV IN. Start REC, wait for one or two cycles of the LFO, then stop REC. You now have a copy of your LFO stored in memory. Unplug the LFO. Using the potentiometer, you can now play back that LFO at any speed, slow it down, speed it up, or even reverse it. The original LFO can be repurposed elsewhere in your patch.

Creating a step sequence

Switch to ONE-SHOT mode (long press on PLAY, three red flashes). Set the source switch to KNOB. Connect a clock to the TRIG input — for example the GATE output of a sequencer like the Korg SQ-1, or a simple square LFO. Press REC. The LED turns solid red, indicating the module is armed and waiting for the first clock pulse. Once the clock starts, recording begins automatically and each pulse captures the current potentiometer position. Slowly turn the potentiometer to draw your sequence. Press REC again when you have enough steps — the module will wait for one last clock pulse to cleanly end the recording. Now, connect the same clock to TRIG: each pulse advances one step and the sequence loops automatically. Your potentiometer has become a sequencer.

Modulating playback speed

During playback in LOOP mode, connect a slow LFO to CV IN. The playback speed will vary with the rhythm of the LFO, creating organic tape-speed effects. The potentiometer sets the base speed, and the CV adds movement on top.

Using gate mode

In LOOP mode during playback, connect a gate signal to TRIG (for example a sequencer gate output). Playback only runs when the gate is high. When the gate is low, the output freezes. You can create rhythmic "freeze" effects synchronized to your music.

Using bipolar output for audio-rate modulation

Set the output range switch to bipolar. Record a fast LFO or a complex modulation source via CV IN. Play it back and connect CV OUT to a VCA CV input or an oscillator FM input. Because the output now swings both positive and negative, you get true bipolar modulation — essential for effects like vibrato, tremolo, and FM synthesis where the modulation needs to push both above and below a center point.

Practical tips

Regarding recording duration, the module uses a flash memory chip that allows approximately 70 minutes of continuous recording. In clocked mode, the duration is even longer because each step uses very little memory. In practice, you will never reach the limit.

The recording is saved automatically to flash memory as soon as you stop REC. It is reloaded automatically when you power on the modular. You don't need to do anything to save.

Each new recording replaces the previous one. There is no multi-memory — the module stores a single recording at a time.

When the module is powered on and no recording is in memory, pressing PLAY triggers three rapid red flashes to indicate there is nothing to play.

If the green LED stays faintly lit when the module is idle, this is normal — it is a characteristic of the LED circuit at rest, not a fault.

For best results with the clock in ONE-SHOT mode, use the GATE output of your sequencer rather than the SYNC output. The GATE output emits one pulse per step, which is exactly what the CV Recorder expects, whereas the SYNC output might be divided and slower (depending on manufacturer, model, etc.).

Clock resolution determines the fineness of capture in sequencer mode. A slow clock (a few Hz) is suitable for melodic sequences where the potentiometer stays stable between steps. A fast clock (tens of Hz) captures more detailed movements but produces a result that is less distinctly "stepped" and more continuous.

When choosing between unipolar and bipolar output, consider the signal you recorded. If you captured a unipolar source like an envelope or a pitch sequence, unipolar output makes the most of the full voltage resolution. If you captured a bipolar source like a triangle LFO or random modulation, bipolar output is necessary to reproduce the full waveform, with the limitation, however, that input waveforms such as LFOs will have their negative half clipped — except for square waves, which will be reproduced normally. Bipolar is most effective with knob movement recordings since it allows you to record and reproduce the full negative-to-positive range without clipping, producing smooth sine waves if desired. For example, if you use MM's VA2XP stereo panning/crossfading mixer, you can create your own custom panning and crossfade curves since the negative side is necessary to pan to the opposite side of the stereo field or to allow crossfading to the second audio input.

Controls summary

The REC button with a short press starts or stops recording. In ONE-SHOT mode with a clock, the module arms on the first press (solid red LED) and begins recording on the first clock pulse. The second press signals the module to stop on the next clock pulse. The LED blinks red during active recording.

The PLAY button with a short press starts or stops playback. The LED is solid green during continuous playback and blinking green in step mode.

The PLAY button with a long press (more than one second) toggles between LOOP mode (three green flashes) and ONE-SHOT mode (three red flashes).

The potentiometer serves as the recording source when the source switch is set to KNOB, and controls playback speed during playback.

The source switch selects the input: KNOB for the built-in potentiometer, CV EXT for the CV IN jack.

The output range switch selects the output voltage range: unipolar (0V to +5V) or bipolar (−5V to +5V).

The CV IN jack receives an external signal to record, or serves as speed modulation during playback.

The CV OUT jack delivers the recorded signal during playback, or real-time monitoring during recording.

The TRIG / CLK jack receives trigger, clock, or gate signals whose behavior depends on the active mode.

TRIG / CLK behavior by mode

In LOOP mode during recording, the TRIG input is ignored. Recording always runs continuously at 500 Hz.

In LOOP mode during playback, the TRIG input acts as a gate. Signal high: playback loops. Signal low: the output freezes on the last value.

In ONE-SHOT mode during recording, the TRIG input serves as a clock. When REC is pressed, the module arms and waits for the first pulse to begin. If regular pulses are detected, each pulse captures one sample. When REC is pressed again, the module captures one final sample on the next pulse and stops. Without a clock, recording is continuous.

In ONE-SHOT mode during playback, the TRIG input advances the sequence by one step on each pulse. The output holds steady between pulses. The sequence automatically loops when it reaches the end.

Current Firmware version: V1.0

cv_recorder_v1_0.ino.uf2.zip

Download ZIP • 63KB

How to install the latest firmware ?

Step1. Unzip the UF2 file on your computer.

Step2. Unplug the power cable from the module and take it off from your rack.

Plug USB cable into your computer et connect it to the module's USB C plug.

Step3. There are two micro push-buttons on the module (you'll rather use your nails to press them): keep the right one pressed while pressing the left one only ones breafly. Keep the right one pressed until the module appears as an external disc on your computer (on your Finder on Mac or explorer on Windows/Linux).

It will appear as "RPI-RP2".

(Alternative way: keep both buttons pressed while plugging the USB cable. When disc appears release both buttons)

Step4. Drag & drop the unzipped .uf2 file on the disc.

Disc disappears -Done!