Behringer 2600

Behringer’s version of the classic ARP 2600 could be the one you’ve been waiting for.

What a time to be alive! Until early 2020, if you wanted an ARP 2600 you had to be prepared to pay eye‑watering amounts on the secondhand market. But in the last two years, there have been brand‑new 2600s available for all budgets. Korg were first out of the gate with the ARP 2600 FS (full‑sized) back in January 2020 (a limited edition that has now sold out). Behringer were next with their 2600 — on review here — and Korg subsequently announced a miniature version too, the ARP 2600 M. Considering the ARP 2600 hasn’t been available to buy for 40 years, the 2600 is like the proverbial bus — you wait for ages, then three come along at once.

The ARP 2600 is a 50‑year‑old design classic. It was the first semi‑modular synthesizer playable without a single patch cable. The internal connections needed for a fully functioning synth voice are pre‑wired but can be re‑routed with a patch cable. Its logical panel layout and use of faders instead of knobs made it popular with both beginners and experienced synthesists. ARP also made the shrewd marketing move of promoting it heavily to educational establishments. Lastly, the ARP 2600 was relatively affordable compared to the Moog Modular, Buchla 200 and ARP 2500 that preceded it.

The 2600 design offers the classic cornerstones of a good semi‑modular synthesizer: three oscillators with low‑frequency modes, noise generator, low‑pass resonant filter, five‑channel mixer, ring modulator, two envelopes, envelope follower, VCA, preamplifier, spring reverb and a host of CV and audio processing tools like inverter, lag, switch and DC sources. The 2600 is a classic because it offers enough analogue tools to keep the most prolific sound designer busy for decades.

Behringer’s recreation of the 2600 — which I’ll refer to as the B2600 from here on — sticks mostly to the original design. The basic design and layout are instantly recognisable. With that in mind, this review will focus mostly on what is different, without going over many of the details that we already know.

Anatomy

The B2600 comes in three flavours: the original ‘Christmas Tree’ orange and black design (on review here), the Grey Meanie and the Blue Marvin. These latter two are special editions that follow the colour schemes of the original Grey Meanie and Blue Marvin 2600s made back in 1971. Behringer say these models contain upgraded components to make them sound better, although they provide no further details. The more important difference is that the special editions have real spring‑reverb tanks, whereas the black and orange version uses a digital reverb effect. I suspect most buyers will want the authenticity of a real spring reverb but perhaps if you’re gigging or looking for a lower noise floor, the digital version might be a good thing.

An original 2600 is around 33 inches wide. The B2600 is rackmountable (8U), meaning its width is 19 inches. To achieve this, everything has been squeezed in and some of the synthesis modules like the preamp, envelope follower and ring modulator have been relocated to make better use of space. Another real‑estate saver is the lack of speakers, which made sense in the original ’70s design but I doubt many people will miss them here. Considering the B2600 is two thirds the size of the original, it doesn’t feel cramped. Behringer have even squeezed in more faders — there are 63 versus 57 on the original — to accommodate new features.

New Features?

Although Behringer have aimed to recreate the original almost exactly, they have done some tinkering along the way. This could be a legitimate cause for concern but thankfully they have managed to keep the spirit of the original intact whilst only adding thoughtful improvements that even owners of the original 2600 couldn’t argue with.

Take, for example, the oscillators. The original 2600 design only has one oscillator capable of pulse‑width modulation. That same oscillator was also the only one able to produce a sine wave. With no dedicated LFO (unless you had the optional 3620 keyboard), there was no way to have a sine wave modulating pulse width. Behringer saw this shortcoming and have upgraded its oscillators. All three can now do PWM, with two having CV inputs. They’ve even added extra waveform outputs on oscillator 3. Furthermore, they’ve added the section from the ARP 3620 keyboard that deals with duophony, portamento, and has that LFO. The LFO is precious because it means you don’t have to use one of the oscillators in low‑frequency mode, although that option is still there if required.

...the B2600 adds two sync switches in the oscillator 2 and 3 sections. These allow their respective oscillators to hard sync to oscillator 1.

One common modification of ARP 2600s was to allow sync between oscillators. The original design didn’t include this, but the B2600 adds two sync switches in the oscillator 2 and 3 sections. These allow their respective oscillators to hard sync to oscillator 1.

The keen‑eyed will spot a couple of other additional switches, one in the filter area, and one underneath each envelope. The Filter switch allows you to switch between two filter designs, the 4012 and the 4072. The 4012 filter, used in the earliest 2600 designs, was a copy of Moog’s ladder filter and ARP were forced to change it after legal action by Moog. As ever, people will argue about which filter was better, but here we have the luxury of switching between them at will. They sound a lot more similar than I had expected. In a fairly vanilla patch, I could detect no difference even with high resonance values. Where I could begin to hear variation was when using audio‑rate modulation. Even then, the difference was minimal. Whether this is a true representation of the differences between a 4012 filter and a 4072 filter, I’d rather not speculate, but here at least I would question the need for two such similar‑sounding filters.

The envelopes generators used in the 2600 design were not especially flexible, by today’s standards. Neither the ADSR nor the AR envelopes could be described as snappy or particularly long. Again, Behringer have spotted an opportunity and added a switch underneath each envelope that allows you to halve or double the original lengths of the envelope stages. This is great news if you like making short percussive patches or longer sounds which need less urgent movement.

MIDI? Yes, Please

Another improvement is the addition of MIDI. Both traditional MIDI DIN and class‑compliant USB connections are supported. For those who like to keep it real, CV/gate is of course still an option. Incoming MIDI is automatically connected to the envelope triggers and oscillator pitch. The MIDI channel is set using a set of DIP switches on the back of the unit. It seems a little retro but it works, and as long as you don’t need to change the incoming MIDI channel too often it shouldn’t present any issues.

Another area that might look unfamiliar is the Keyboard/Portamento section in the bottom left. This is taken from the optional ARP 3620 keyboard I mentioned earlier. This section takes the MIDI input, as it would have done the keyboard input from the 3620, and gives you helpful outputs such as trigger, gate and pitch CV. There is a slider for portamento and an LFO which is primarily designed for vibrato but can also be routed elsewhere thanks to some dedicated outputs.

As with the original 3620, duophony can be achieved using the extra CV output for ‘upper voice’. This works automatically with the MIDI input. The rest of the 3620 section is true to the original design except for one omission — the octave switch. I presume this was ditched due to a lack of space. It’s not a deal‑breaker by any means, but it is a shame not to have quick octave switching anywhere onboard. Also missing is the 3620’s pitch‑bend knob, but the B2600 supports pitch bend via MIDI. There is one catch, however: you can only change the pitch‑bend range via a SysEx message. By default, it’s set to two semitones, but by sending SysEx you can change it between zero and 12 semitones.

Another MIDI problem I discovered is that the B2600 does not like to receive MIDI Clock. It doesn’t support clock and has no use for it, but I spent an hour trying to diagnose why occasional MIDI notes were not producing any sound. As it turned out, the sequencer I was using at the time was sending MIDI Clock. As soon as I disabled it, the B2600 behaved. Whilst not a huge issue, it’s not something that ought to happen and it could prove problematic for anyone hoping to put the B2600 into a chain that requires MIDI Clock.

Conclusion

Although I don’t have an original ARP 2600 to compare with, I am well accustomed to the 2600 design. A few years ago my friend Sean built three Human Comparator TTSclones. I was lucky enough to end up with one. The TTS(Two Thousand Six Hundred) was a build‑it‑yourself 2600 clone project. Before Korg and Behringer announced their versions it was the only way to get a new and relatively affordable 2600.

Attempting sound comparisons between an old 2600, the TTSand the B2600 is not particularly useful. After all, even two original 2600s will not sound alike. The good news is that the B2600 sounds great. In all the ways that matter, the B2600 feels and sounds like a 2600. It does sound different to my TTS‑ and I’m sure to any real 2600 you might put it up against — but not in a way that would make it unrecognisable or unpleasant. The response you get when moving sliders, or patching an output into a hitherto untried input, is entirely legit and every sound I made on the 2600 sounded authentic — full of analogue goodness.

That ’70s sound is perhaps only let down by one aspect. To my ears, the digital reverb lacks the character and charm of a real spring. It’s a decent approximation, and it even has some advantages like a much lower noise floor and a resistance to creating low‑frequency thumps when you knock the outer case. But a real spring reverb is such an integral part of the 2600, I can’t imagine what Behringer were thinking replacing it. Thankfully, they rectified this in the Grey Meanie and Blue Marvin versions, so I would advise anyone looking for the fullest 2600 experience to seek out one of those instead.

These small improvements may not seem like much, but show an understanding and sympathy to the original design which I was very impressed with.

Overall, Behringer’s little improvements to the 2600 design are well considered and don’t detract from the authenticity of the experience. PWM input for oscillator 3, extra waveform outputs, filter switch, MIDI/USB, envelope‑time multipliers, ADSR gate input... These small improvements may not seem like much, but show an understanding and sympathy to the original design which I was very impressed with.

Probably the most impressive thing about the Behringer 2600 is the price. When the original 2600 was released in 1971 it cost $2600 (of course it did!). Adjusting for inflation, that would be around $17,500 today. The Behringer 2600 costs just £449$659 — astonishing. We live in a time where electronic musical instruments, both vintage classics and modern, are cheaper and more plentiful than ever before. I suspect Behringer’s 2600 will sell very well indeed.