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Page 2: Radikal Technologies Delta CEP A

Semi-modular Synthesizer By Rory Dow
Published February 2020

Snapshots & Presets

Up until now, you might be thinking this is a straightforward synth. Snapshots are about to change that. Up to 40 presets can be saved and recalled, and within each preset, up to eight snapshots can also be stored. A snapshot, as far I can gather, is exactly the same as a preset, but fundamentally they are used for different things. A Snapshot can be a subtle variation in a sound, or it can be a completely new sound. Once at least two snapshots are stored in a preset, you can morph and jump between them in a variety of ways.

The Delta CEP A's rather dazzling LEDs in action. Don't be surprised if tourists gather beneath your bedroom window having mistaken its light show for the Aurora Borealis.The Delta CEP A's rather dazzling LEDs in action. Don't be surprised if tourists gather beneath your bedroom window having mistaken its light show for the Aurora Borealis.

The simplest way is to use the large Interpolator knob, which can select or smoothly morph from one snapshot to the next. Think of it as a mod-wheel on steroids. It's a great way to inject some performance-based changes into a sound.

Another mode allows snapshots to be sequenced. In this mode, all eight snapshots are recalled in order according to a clock division of your choosing. Once the eighth snapshot is reached, it wraps back around to the first. Clock divisions range from two bars to 1/16th note. The snapshot sequencer will sync to MIDI, analogue or internal clock. You can choose to have the sequencer morph smoothly or just switch to each snapshot and a special envelope mode will cause triggers on each snapshot, essentially turning this into a self-contained eight-step sequencer. By storing different pitches in each snapshot you can play simple eight-note sequences while the patch morphs in other interesting ways. I much preferred leaving the envelope trigger mode off, and sequencing from an external sequencer. Having sounds that continually morph over up to 16 bars whilst you noodle away is ludicrously good fun.

Snapshot morphing can also be done with modulation wheel, velocity, aftertouch or CV input (the LFO Depth CV input gets repurposed for this). It took me a while before the possibilities of the snapshot morphing set in. For example, you might want to make a sound that brightens with velocity, but also has envelope decay that gets longer and an oscillator waveform that changes. In a more traditional synth, you might achieve this with a modulation matrix, creating separate matrix entries for each velocity destination. Here, you simply create one snapshot, in the first slot, for minimum velocity, then change the sound as many ways as you like and save it as the last snapshot. Now the velocity will be used to interpolate between the two snapshots. If you need to adjust something at the higher velocities, simply recall the relevant snapshot, make a few tweaks and save it again. It's a much more fluid and musical way to deal with modulation than a modulation matrix, which feels archaic by comparison.

Using the Interpolator to manage snapshots and presets can be confusing. Without an LCD screen, settings have to be indicated with with a series of coloured LEDs and many buttons take on a dual purpose which isn’t always obvious. Be prepared to read the manual, several times, but do persevere, because it’s worth it.


I was initially underwhelmed. On first inspection, the Delta CEP A appears to be rather under-spec'ed for its price. A single oscillator, LFO and envelope doesn't compare well against other synths in the price range. However, once you begin to master the Interpolator, and, more specifically, the snapshot morphing, unexpected things begin to happen. Snapshot morphing is, in my mind, the biggest reason to own this synth. It is probably one of my favourite features of any synth released in the last 20 years.

So in the end, this synth presents something quite unique. The sound generation engine is nothing ground-breaking, but it does sound good. Having analogue and digital filters is a nice touch. Its monophonic nature means it is best suited to bass and lead sounds, although the paraphonic mode means you can breakaway to simple pads and polysynth sounds. I particularly enjoyed the oscillator's chord mode, which could turn any sound into a techno-rave, chord-memory stab. Combining that with snapshot morphing turned a potentially overused, but admittedly lovable, sound into something special that twisted and morphed in a musically intelligent way.

In terms of everyday use, the Delta CEP A can be frustrating. Almost every control and button has multiple functions, and whilst the front panel labels a good deal of them, some are rather well hidden. Despite consulting the manual several times regarding the subject of snapshot recall, I continually forgot the exact and intricate button sequence to make this happen, causing several cases of mild vexation.

Despite that, I was left with a feeling of excitement. I can't think of another synth like the Delta CEP A. It replaces traditional modulation systems, including the terribly grey modulation matrix, with something far more musical and interesting. You will need an external analogue or MIDI sequencer to get the best from it, though.

There is a question about who the Delta CEP A will appeal to. The Eurorack module is clearly an attempt at a starting point for a Eurorack system, and it would indeed fulfil that role, although it is rather expensive and complicated. Eurorack can be a daunting world to explore and sometimes simplicity is a good thing, at least in the early days of building a system. The desktop version will appeal to more traditional synth fans, but its Eurorack heritage is very obvious and if it had been designed from the ground up as a desktop synth, I suspect it would work rather differently. So in the end, the Delta CEP A doesn't do either job perfectly, but straddles the two.

Nevertheless, the Delta CEP A is a great synth. Radikal Technologies should be applauded for heading off piste with the modulation system. It's chock full of analogue-flavoured goodness and the morphing system will keep the sound twisting and turning for days. It is expensive, but there's nothing else quite like it.


There are plenty of semi-modular, desktop synths out there, but none with the snapshot morphing capabilities of the Delta CEP A. But, synths equally at home in the Eurorack case or on the desktop might include the Moog Mother 32, Behringer Neutron, Pittsburgh Modular Microvolt 3900, Make Noise 0-Coast and Roland System-1m.


It is possible to backup or share single patches, a bank or all presets. Because the Eurorack version doesn't have a MIDI output port, this can't be done by the normal MIDI SysEx method. Instead, it dumps the data at the audio output. The manual suggests you can record the audio on your mobile phone, DAW or "traditional tape deck". In order to restore a preset data dump, you just need to be in the correct Utility menu, and the synth will listen for data at the External input in the Mixer section.


The Delta CEP A includes a MIDI to CV converter. From the MIDI input port various MIDI messages are converted. Notes are converted to gate and 1V/oct CV. A MIDI control change of your choice is converted to CV output, and MIDI clock is converted to clock and resets the output. On the desktop synth version, the MIDI to CV functions feel redundant because all those connections are already internally wired. As a Eurorack module, however, whilst they are still internally wired, they could be useful for driving other modules in your system.

Firmware Update 1.5

Just as we were wrapping up this review, Radikal Technologies released firmware version 1.5 which adds a number of useful functions.

The biggest feature is probably the new reverb effect, which can be applied in parallel with the other effects. Parameters available for tweaking include time, damping, width, feedback and dry/wet. To my ears, the reverb sounds good by onboard synth standards.

There is also a selection of new internal modulation destinations for the LFO and envelope. This means you can modulate things like the oscillator waveform, TLM, pitch, level, filter cutoff, resonance, overall volume and even the LFO rate and depth (when using the envelope as a source) without using patch cables. All of the new modulation destinations, and the reverb effect, are saved in snapshots so you can use them all in snapshot morphing.

A number of other small but welcome tweaks include shift-lock, CV control over oscillator level and saturation balance and analogue clock sync for the LFO. Oh, and MIDI Program Change can now be used to change presets. Overall, a most welcome update.


  • Analogue and digital filters.
  • Sounds great.
  • Snapshot morphing is superb.
  • Build quality is excellent.


  • The price.
  • You will have to read the manual to master its finer points.


Radikal Technologies have tried, and mostly succeeded, to create something a bit different. Delta CEP A blurs the lines between modular, digital and analogue, and manages to throw in a very unique snapshot morphing feature that is both musical and fun.


£799 including VAT.