Wednesday 1 September 2021

Doepfer LC1: Miniature Modular

Clowns to the left of me, jokers to the right, and earlier in the year I built a modular synthesiser. Why? Because, girl, you'll be a woman soon. It was as big as four rooms.

Four rooms. Look, I'm not going to do this any more. I was going to fill this post with references to Quentin Tarantino films from the 1990s but I'm not going to do that. Let's move on. Here's what my modular synth looked like, the last time I photographed it:


It's not a true romance, because the bottom half is mostly a Behringer Model D; only the top half is made out of modules. It's built into a Doepfer LC6 case, which is 84hp wide and two layers tall. The whole system is about the size of a slightly smaller-than-usual PC case, but not as heavy.

I've made a lot of music with it, viz:


There's a stereotype that Eurorack is addictive. The individual modules aren't that expensive, but they're desirable and the cost mounts up. £70 here. £120 here. £60 there. You have to give up smoking and drinking in order to afford more modules. Then you start cycling to work instead of driving. You cancel your gym club membership and sell off the Peloton. Before long you're a shell, a shattered ruin.

Would my music benefit from a ribbon controller? An FM radio? A low frequency oscillator that takes two hours to complete a cycle? Probably not, but how will I know unless I try? And by "try" I mean "spend money".

They're so beautiful.

But let's imagine that you're disciplined, and you want to build a little modular synth without spending too much or taking up too much space. Doepfer's smallest case is 32hp wide, which is either a challenge or too limiting depending on your outlook, but the company makes a slightly-less-miniature model, the 48hp Doepfer LC1:

It has twelve power connectors, which is nice but overkill. 48hp is enough for five or six regular-sized modules. A company called 2HP specialises in 2hp-sized modules, so if you buy lots of 2HP modules you might run out of power connectors, but you'd have to try really hard. Perhaps you could fill the empty space with passive low pass gates and attenuators. I'm digressing.

How did I fill my LC1? At first I did this:


Doepfer warns that the LC1's power supply is less stable than the power supplies in larger cases, which can cause analogue oscillators to go out of tune. Digital oscillators shouldn't be affected, so initially I built my system around Mutable Instruments Plaits.

From left to right the case has Plaits, a Doepfer A-101-2 filter, a Doepfer A-118 noise generator, a Doepfer A148 dual sample-and-hold, and a Behringer 140 dual-envelope-plus-LFO. It would be nice to have more LFOs, but I felt that the S&H circuit would compensate for that. The following tune uses this setup:


It also features a Meris Hedra pitch-shifting delay pedal, and Valhalla's Supermassive reverb VST.


The Hedra is great fun. I'll write about it at some point. It has three delay lines, which can either echo the sound as-is, or they can shift the pitch. It works best with monophonic sources, and preferably simple waveforms, and sometimes it goes wrong, but when it works it's like having someone play chords along with your music. About the only technical issue is an odd crackling at very high frequencies, which means that if I feed it into a reverb I have to roll off the top end otherwise the reverb result sounds crunchy. Enough of the Hedra.

How much did this modular marvel cost? Brand-new the LC1 is around £140, Plaits is £195, the A-101-2 £95, the A118 £60, the A148 £60, and the 140 £75, which is a total of £625. Ouch. That's not cheap. And you still need a bunch of cables, and a way to control it all. I used an Arturia Beatstep (£75), which doubles as a MIDI-CV interface, with an odd quirk whereby everything is transposed up two octaves. I also have Mutable Instruments' Yarns, an excellent MIDI-CV interface, but at 12hp it would take up as much space as Plaits.

But! with the exception of the Behringer 140 I slowly accumulated all of these modules on the second-hand market, from eBay, so I paid around £450, which is still not cheap, but there is an even more valueful option. Consider the following:


This is built around a Behringer 112 dual VCO, which is a pair of analogue oscillators. Despite Doepfer's warnings about instability the 112 worked fine and remained stable, although tuning it was difficult because the tuning knobs are very sensitive.

The setup above has the LC1, a multiple (£20), the 101-2 filter, plus the Behringer 112 and 140 modules. The Behringer 112 costs around £80 brand-new, so the whole setup would have been £410, but as mentioned I bought most of it second-hand and thus got it under £400. The end result is sonically in the same ballpark as a Roland SH-101, with a second oscillator instead of a sub-oscillator. It would benefit from a noise source and an attenuator, which I could perhaps have fitted into the case if the envelopes and LFO were smaller.

Here's what it sounds like, fed into Logic, this time with a Strymon El Capistan tape delay pedal:



That tune begins with the two oscillators playing the same notes, an octave apart, and then after a short while I play a different set of notes through the second oscillator. It all goes into the same filter, modulated with the same envelope, so although there are two notes at once the result is paraphonic rather than polyphonic. One thing to note is that the system doesn't have a VCA. I use the filter instead.

Oh yes, this setup has a Doepfer A-103 VCF6, which is modelled on the filter in a Roland TB303. At higher resonance values the A-102 shrieks loudly and outputs a sine wave. The A-103 on the other hand just gets more squelchy.

In this setup I'm using it as an expansion for a Behringer Model D, passing the two extra oscillators through the Model D's filter and envelopes, and passing the output through the LC1's spring reverb.

Could I have pared things down even more? I could have eliminated the S&H module, saving £60 at the cost of some flexibility. Behringer's System 100 range also includes the 110, which sells for £80 and has a single VCO, a VCA, and a VCF. A setup that consisted of a Behringer 110, 112, and 140 would fill the case for £380. Alternatively I could have eliminated the filter and used my TAKAAB 2LPG, but this module doesn't have resonance, so the results wouldn't be squelchy.

Is a 48hp case practical? On the positive side the system above is small enough to fit into a backpack and has roughly the same sonic power and flexibility as a Roland SH-101 or a MiniMoog, at a price of around £400. It's not quite a Korg MS-20 but if the modules were jiggled around it would come close. It would also be a good housing if you have a computer-based, virtual-instrument setup but wanted to try out 2HP's Pluck or Mutable Instruments' Plaits or something analogue.


This minimal setup uses a pair of Volcas and an Arturia Beatstep to generate sync pulses, and Dexed - a VST simulation of a Yamaha DX7 - being played with an Arturia Beatstep. The only two modules that are actually doing anything are the dual logic gates and the 2LPG.

48hp is however very limiting for a complete self-contained instrument. I still had to do a bit of jiggery-pokery with TipTop stackable cables on the dual VCOs because there wasn't room for any multiples. Doepfer's 84hp LC3 case is a much better option for that. 48hp does however make a lot of sense as a break-out box for passive modules, or modules that you rarely use, e.g. the dual logic gates in the video just above.