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ARP 2600 M

Analogue Synthesizer By Gordon Reid
Published April 2022

ARP 2600 M

Back by popular demand: Korg have miniaturised the ARP 2600 but kept the spirit and sound of the original very much alive.

I’m sure that there have been millions of words written about the ARP 2600, and I have probably contributed more than my fair share over the years. But the world never seems to get tired of what might be ARP’s finest creation. It’s not as impressive as the ARP 2500, nor is it as convenient as the Odyssey, and it’s certainly not as easy to use as the ProSoloist, but it embodies a wonderful compromise of the impressive, the convenient and the straightforward.

Now, having secured the blessings of David Friend, co‑founder and eventual President of ARP Instruments and one of the designers of the original, Korg have recreated the 2600 not once, but twice. I reviewed the first version, the ARP 2600 FS, in late 2019 and fell in love with it (see March 2020 SOS review). I don’t think that I’ve touched my original ARP 2600P since. This is because, after I returned the review unit to Korg, I was unable to stop myself from ordering a new FS which, as well as being perfectly calibrated, is clearer, brighter, quieter, and hasn’t suffered from a crackly or intermittent connector in two years.

It was perhaps no surprise when the FS sold out almost immediately, nor when — a year later — Korg announced that they would be shipping a smaller, more affordable and more obtainable version, the ARP 2600 M. This has now arrived. So, has Emperor Zorg’s malevolent Shrink’O’Matic harmed anything, or has it simply made the 2600 more convenient and more attractive to a wider spectrum of potential owners? Let’s find out.

A Miniature 2600 FS?

When I opened the box from Korg, I had a surprise. Rather than discovering the packaging protecting the 2600 M, or perhaps an inner box containing the packaging containing the 2600 M, I found myself removing a small suitcase that contained the synth itself together with its power supply, a manual, a sheet of ARP stickers, a packet of patch cables and a Korg microKEY USB keyboard (the last of which isn’t part of the M, but an optional accessory) all ready for use. It’s a very unusual approach, but I have to admit that I was impressed. This was a good start.

The M lacks the wooden case of its larger sibling, which means that it also lacks the lid that protects an original 2600 or the main cabinet of the FS when they’re not in use. Instead, it has a wrap‑round steel case with all of the controls on the front and various connections on the left‑hand side. Nevertheless, you would have to look hard to distinguish between the front panel of the M and that of a shrunken FS because there’s just one difference: the multiple has shrunk from four sockets to three. It’s easier to spot the changes when comparing it with the original — outputs for CV2 (the uppermost note played) and the modulation CV (MIDI CC01), the addition of the ARP4012 (1971‑1975) or ARP4072 (1976‑1981) filter selector switch, and the loss of numerous calibration trimmer access points. In addition, the M uses Odyssey‑style slider caps whereas the FS retained the larger caps from the original. This makes perfect sense in the context of the smaller panel but, given the 40‑percent shorter throw of the faders and the loss of the little pointers on the original’s caps, this makes it harder to draw and recreate sounds when using printed patch sheets or the time‑honoured method of making chinagraph marks on the panel itself. Such differences aside, the M is clearly the same synthesizer as the 2600 and the main cabinet of the FS; even the elliptical speakers have been retained, although these are smaller than before. It would have been great to see these replaced with extra VCAs, mixers and multiples, or even something akin to the excellent CMS upgrades from Phil Cirocco, but maybe that would be hoping for a bit too much. Oh well... one can dream.

The biggest functional change between the M and the FS is, therefore, the omission of the 3620 keyboard. This means that (in addition to the loss of the pressure‑sensitive keyboard itself) the M lacks the FS’s LFO, its arpeggiator/sequencer with its associated Latch switch (which means that Gate Repeat has gone), its two CV inputs, its single/multi triggering switch, its two‑octave up/down lever, and the ability to control portamento.

The loss of the LFO places the M — like the original 2600 with a 3604P keyboard — firmly in Minimoog territory; unless you jump through some significant hoops, you can have a triple‑oscillator sound, or you can have a dual‑oscillator sound with a conventional LFO. Its loss also makes the creation of common sounds that use cyclic PWM almost (but not quite) impossible unless you employ external modules. What’s more, the lack of a patchable VCA means that you have to use the Ring Modulator as a VCA if you want to control the modulation depth using a wheel.

Small(er) but perfectly formed: the M has an all metal enclosure, rather than the wooden case of the FS, and 3.5mm patch cables are the order of the day, otherwise the two are almost identical.Small(er) but perfectly formed: the M has an all metal enclosure, rather than the wooden case of the FS, and 3.5mm patch cables are the order of the day, otherwise the two are almost identical.

In contrast, while the M appears to have lost its single‑ and multi‑triggering options, it hasn’t; they’re tucked away where you won’t find them unless you read the manual. You select between them by pressing sequences of the Manual Start button while switching on the M’s power. Similarly, the M still offers the FS’s voice assignment modes, and different sequences allow you to select between the original 2600 behaviour (CV2 is retained when you release the uppermost key so any oscillators playing at this pitch don’t drop to the lowermost) and the Odyssey’s behaviour (CV2 drops to the lowermost key when all others are released).

Although it’s not explained clearly in the manual, portamento has also been retained even though there are no physical controls for it; you can switch it on/off using MIDI CC65 and adjust its rate using MIDI CC5. Unfortunately, these settings are lost when you switch the M off and, even if you set it up each time before playing, it’s unlikely that making changes will be practical during performance. Of course, you can use the lag processor to give yourself the ability to control a short glide while playing, but this precludes its use for anything else.

If I’m honest, I love the size and heft of the FS, but I accept that many musicians nowadays view ‘compact’ as a benefit rather than as an insult. Nonetheless, at 20.5 inches wide (around 60 percent of the original) the M isn’t going to fit into a 19‑inch rack. Likewise, its height of a little over 12 inches (again, around 60 percent) precludes its use within any conventional modular system. Yet there’s no doubt that it’s ideal for use alongside modern modular synths, to the extent that Korg have even reduced the external voltage required to trigger the contour generators from 10V to 5V, which increases its compatibility with (in particular) Eurorack equipment.

So, how should we view it? Is it a self‑contained synth that benefits from the addition of external modules such as LFOs, multiples, slew generators and VCAs? Or is it a high‑class colony of three oscillators, dual filters, a noise generator, two contour generators, a complex S&generator, a ring modulator, an envelope follower, an electronic switch, a preamp, four voltage processors, an audio VCA and a spring reverb that extend your existing modular synth far beyond its existing capabilities? Of course, it’s both. How you view and use it is up to you.

The Sound

Despite the physical changes, Korg claim that the M’s circuitry and components are the same as those in the FS, and therefore sonically accurate to the original. So I placed it next to my 2600P to gauge its authenticity and, whether I was programming leads, basses, orchestral imitations, percussion or effects, I was able to create patches on the two that were all but identical. I was also able to obtain sounds from the M that the original was unable to produce, often because Korg have improved (ie. extended) the miserly attack, decay and release times of the original’s contour generators.

Nonetheless, there are some differences in the sounds of the oscillators and the filters, and the M’s main audio signal path is noticeably quieter than the original’s. The same is true of its spring reverb, which Korg’s marketing department describes as “re‑engineered and adapted to the new size body to the same lush effect”. They’re wrong. It’s lusher. It’s also quieter, with a wider bandwidth and an increased maximum reverb time. To be fair, some vintage synths benefit from a bit of noise — for example, the Emerson Moog Modular would have sounded very odd with a pristine signal path — but the 2600 isn’t one of them. This may be heresy but, like the FS before it, I think that the M is a clearer, brighter, quieter and — dare I say it? — sonically better synth than my 50‑year‑old 2600P.

But it’s not perfect (no synth is) and I found two deficiencies that require mention. The first was that the M can generate a low‑level whine. For much of the review, I had it connected to my Mac via USB and to two keyboards: the supplied microKey via USB and a second via 5‑pin MIDI, which was itself connected to the Mac via USB. The outputs from both the M and the Mac were then connected to the same mixer and, in addition, all the devices were powered from the same ring main. There were multiple loops here so I suspected that these were the cause, but it turned out that the microKey was the culprit. Connecting a different MIDI keyboard to the end of the same cable eliminated the problem.

The second was that — like the FS — the M’s MIDI specification is very limited: just note on and off, pitch bend, modulation CC01, and the programmable portamento. None of the sliders or switches transmit messages, nor is anything received to affect the settings that they control. When I’ve raised this issue with manufacturers in the past they’ve explained that adding the VCAs necessary to implement a more extensive MIDI specification might compromise the authenticity of a clone, but I’m not sure that I fully believe this. Either way, the M offers what it offers.

This may be heresy but, like the FS before it, I think that the M is a clearer, brighter, quieter and — dare I say it? — sonically better synth than my 50‑year‑old 2600P.

To Buy Or Not To Buy?

Korg claim that the M is a “genuine ARP 2600 in a more convenient size” and, in comparisons with my 2600P, it acquitted itself very well. It’s not what one could call a low‑cost synth but, when you consider what an original 2600 would cost and the amount of work that you might have to do even if you could find one — replacing sockets, cleaning or replacing faders, replacing capacitors, upgrading VCAs, and so on — the M starts to feel like a bit of a bargain. If the loss of the 3620 keyboard isn’t an issue and you would like to obtain the 2600 sound from something smaller and more affordable than an FS... well, here it is.  


Compared with the original ARP 2600P:

  • You can select between 4012 and 4072 filter modes.
  • The Upper CV is available from the front panel.
  • The modulation wheel CV is available from the front panel.
  • It offers 5‑pin and USB MIDI.
  • It has quarter‑inch audio outputs.
  • Auto Power Off will switch it off if you forget to do so.
  • You can’t connect a 3620 keyboard or its equivalent.
  • It has a three‑way rather than a four‑way multiple.

Compared with the Korg ARP 2600 FS:

  • It has unbalanced rather than balanced audio outputs.
  • It has a different reverb.
  • There’s no immediate way to control it using aftertouch.
  • It has shorter faders with Odyssey‑style caps.
  • It has an additional USB A socket.
  • There’s no 5‑pin MIDI out or thru.
  • You can’t connect a 3620 keyboard or its equivalent.
  • It has a three‑way rather than a four‑way multiple.
  • It uses an external PSU rather than an internal power supply.

The Side Panel

ARP 2600 MMost of the M’s I/O is different from that of the FS. For example, whereas the larger model has balanced XLR audio outputs, the smaller has unbalanced quarter‑inch jack outputs. Alongside these, the M has just a MIDI in socket, having lost the MIDI out and thru of the larger model.

There are differences in the USB and keyboard connections too. The FS has a single USB B and a dedicated connector for the 3620 keyboard, but the M replaces these with a USB B and a USB A that allow you to connect any class‑compliant MIDI keyboard controller.

Finally, the M has an input for an external PSU, whereas the FS has an IEC mains input for its internal power supply. The one common feature here is the set of five DIP switches, four of which select the MIDI channel, and the fifth of which determines whether Auto Power Off is enabled or not.

Bundled Software

Like many recent Korg products, purchasing an M allows you to download a software bundle. This includes a basic DAW as well as audio processing plug‑ins and Korg’s own Gadget 2, M1 Le, and Module. I’ve seen different bundles offered with other Korgs (there are four variants at the moment) but it didn’t occur to me that a clone of a 50‑year‑old analogue monosynth would come with software. Once I had overcome the shock (it didn’t take long!) the bundle came as a pleasant surprise because there’s genuine value here.


  • Yet again, it really is an ARP 2600.
  • It sounds authentic, but simultaneously cleaner and brighter than the original.
  • It offers several improvements over the original.
  • It’s MUCH cheaper than a vintage ARP 2600.


  • Authenticity cuts both ways: it has some of the same deficiencies as its forebear.
  • With no equivalent to the 3620 keyboard, some important functions are missing or hard to access.
  • The MIDI spec is very basic.
  • It uses an external AC/DC power supply.


The ARP 2600 remains one of the most desirable monosynths ever built, offering a degree of flexibility that was mind‑boggling in 1971 and remains uncommon to this day. The ARP 2600 M recreates it with great accuracy, but also offers a number of valuable improvements. You’ll have to decide whether the loss of the 3620 is an issue for you but, either way, there’s a great deal to like here.


£1699 including VAT.