A deliberately retro analogue drum machine with a slightly quirky approach. Greg Scarth puts it to the test.
The philosophy of the AVP Synth Ritmobox is simple: it’s a deliberately retro analogue drum machine, heavily inspired by the classic machines of the 1970s and 80s. You can debate whether the devotion to 70s-style hand-built, discrete, through-hole electronics is important in terms of the sound itself, but the overall approach is an appealing one, bringing to mind vintage classics like the Roland TR-606 and TR-808, brought up to date with much more versatility in terms of sound sculpting and the addition of MIDI control.
The design of the Ritmobox is decidedly old-school but there’s a nice weight and sturdiness to the machine which makes it feel like it’s built to last. You’d have no qualms taking it out to a live show. The features are simple and easy to get to grips with, which isn’t a bad thing; you can plug the Ritmobox in and get started without really needing to refer to the manual, and just about everything is immediate and intuitive in terms of front panel controls. There’s no menu-diving here, and everything is immediately accessible via a dedicated control, with the exception of a few fairly simple button combinations for things like setting the MIDI channel or clearing stored patterns.
The Ritmobox has five separate voices, each of which goes to the master output as well as individual outputs on the back panel. Two channels are dedicated open and closed hi-hat circuits, while the remaining three are identical ‘Generators’ with broader controls allowing them to be used for just about any drum sound or percussion instrument you want. The latter approach is a little bit unusual these days; most drum machines feature dedicated circuits tuned to lend themselves to the most common percussion sounds, such as kick drums, claps and snares. The broader flexibility of the three Generators is reminiscent of something like the late 70s Simmons SDS-3, which had four identical channels and left it up to the user to determine which direction the sounds went in.
Starting with the dedicated channels, the two hi-hat circuits are tuned for closed and open hats. They’re completely independent of each other, meaning that you can dial in the two sounds separately. The sound is immediately appealing, packed full of vintage vibes. The Roland TR-606 is my personal benchmark for analogue hats, and the Ritmobox can reach pleasingly similar tones, but the versatility is on another level. Controls are identical for each circuit, with straightforward decay time, filter cutoff and a final knob to blend between the noise generator and ‘metal tone’. Dialling in more metal tone can create other cymbal sounds, with nice clangy metallic rides a particular sweet spot. One quirk here is that the circuits generate sounds independently of each other, meaning that the open hat isn’t affected by the closed one. That’s quite different to the way most drum machines work, where triggering the closed hat will ‘choke’ the decay of the open hat. It’s interesting to hear what can happen when you allow a long open hat decay to ring out underneath a closed hat; it’s not at all realistic but quite distinctive.
The Generator circuits are, by their nature, much more complex to program and capable of a much bigger range of sounds. AVP don’t publish the exact schematic of the synth circuit, but you’ve got nine parameters to control for each one, plus a level control. The sound is generated by a mixture of oscillator and noise generator, with a pitch envelope ‘sweep’, ‘pulse’ kick sound, band-pass filter on the noise generator and LFO modulation. An HR/LR switch chooses high or low resonance, giving a harsher or softer sound respectively. The result is pure, powerful analogue sound. You don’t necessarily need to know all the ins and outs of how the various parameters work, because the tuning of the circuits has been well judged. It’s hard to find yourself making unusable sounds, even if you just tweak the knobs at random. You might suddenly lurch from a thumping kick to a dubby siren if you’re not careful, but everything is usable in some way. AVP provide some example settings for sounds like kicks, snares and claps, but you’ll have just as much fun experimenting to find your own sounds.
You’ve got two options when it comes to sequencing the Ritmobox: trigger it over MIDI, or use the internal sequencer. AVP describe the sequencer as an eight-step design, but it might be better to describe it as a dual-eight-step setup, which can run as either eight-step or 16-step, with the 8/16 button allowing you to quickly switch the sequence length, and the 9-16 button selecting the second half of the sequence. It’s not an uncommon solution, and one which works well here, but that’s not to say there aren’t quirks to the Ritmobox’s approach. There’s no preset storage for sounds, just pattern storage which allows you to store and recall patterns on the fly. As a result, switching patterns relies heavily on the kind of sound you’ve got tuned in on each circuit. You could get around this by always making sure you program, say, kicks on the G1 track/circuit, claps/snares on G2, etc, but it does mean a bit of forward planning is necessary to keep things cohesive for a live performance. Continuing with the Ritmobox’s quirks, there are a few omissions which might have been nice to see. Adjustable swing and an accent option would be nice for the sequencer (although it’s not an issue if you sequence over MIDI). The sound selection button on the sequencer doubles up as a mute control. On the sixth tap of the button, all the LEDs light up and you can use step buttons 1-5 to mute and unmute each of the channels, which is a nice touch. Overall, the built-in sequencer is unique and effective, but I suspect a lot of owners will choose to sequence the unit over MIDI for added flexibility.
Trying to sum up the Ritmobox is easier said than done. It sounds a bit like a vintage drum machine but with much more adjustment of sound and the benefits of MIDI. It’s a bit like the Vermona DRM-1 in terms of old-school approach, but with a built-in sequencer and deliberately more versatile circuits. In general, the retro approach works. It’s not a fully featured modern drum machine by any means, but it doesn’t try to be. The Ritmobox offers heaps of character and proves to be an engaging hands-on instrument to tweak and play with.
Greg Scarth
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