The Korg M3R is a popular synth module for two main reasons... It sounds like an M1 both in name and sonic quality and it's cheap. They usually go for about $150.00 U.S. but I have seen them sold for as little as $75.00. That's a good price for a synth that has the same 16 voice polyphony and Digital Multi Effects as the M1 and T-Series.
Many people buy this synth thinking they are getting an M1 in a rack and are disappointed when they power up the synth and find that the famous M1 factory signature sounds like Universe and Cloud Nine aren't there. But the M3R can easily sound just like the M1 when loaded with M3R Morph.
The M3R doesn't have nearly as many patches available for it as the M1 does. The M1 was extremely popular and most Sound Houses developed patches for it and not the M3R.
M3R patches are not compatible with the M1. That means you can't transfer your favorite M1 patches to the M3R via Midi.
The M3R is limited to Single Oscillator Programs. This can be a serious limitation in the sound creation process. Programs can be "stacked" in Combination mode though to achieve double oscillator "depth".
The M3R can be tedious to operate from the front panel. It's small screen, limited buttons, and buried menus can make everyday operation a pain. This is probably the biggest complaint most users have against the M3R. This problem can be eliminated with the addition of a RE1 Remote Editor or a good Software Editor. You'd be well advised not to tackle this synth without one or the other.
Should You Buy This Synth?
If you've never had a M/T Series synth this is a cheap way to hear what all the fuss is about. But don't judge the entire line on this synth. If you can afford it I'd recommend getting the M1R instead.
If you have a M1 or T-Series synth and are looking for cheap polyphony expansion this might be a good way to go. You double your max polyphony and add two more Digital Multi Effects in the process.
If you have a M1 and are looking for new Multisounds this synth is attractive. For the price of about 2 Korg Card Sets you get 3 times the waveform data and a synth to boot! Good deal.
If you have a M1 EX/M1R EX or a T-Series and are looking for new Multisounds this synth is not the way to go. These synths already have most of the Multisounds found in the M3R and the ones they don't have aren't that big of a deal.
The M3R has 3 megs of Multisound waveform data. That's only 1 meg less than the original M1. The bulk of the Multisounds are derived from the M1's waveform data but some are from the M1 EX/M1R EX and T-Series' expanded Multisounds. Only a few Multisounds are unique to this synth and most of those can be found on Korg's PCM Sound Cards.
The M3R doesn't have a built in sequencer like the rest of M/T Series synths but it does have several demo sequences stored in ROM... and they are arguably better than the M1's factory dermos. Certainly on par with the M1's. Demo sequences can also be found on Korg's M3R Sound Card Sets.
Manual - Korg M3R Manual & Quick Guide in Adobe Acrobat (pdf) format.
M3R Master - Master the Korg M3R Sound Card Sets.
M3R Morph - Turn the M3R into a respectable M1 clone.
Sound Cards - Current Sound and RAM Cards for sale.
Battery Replacement - Step by Step Battery Replacement Guide.
Specs - Side by side comparison of all M/T Series synths.
Effects - Info on the Digital Multi Effects used in the M/T's.
Sounds - Korg's Sound Cards for the M3R.
Accessories - Info on RAM cards and more.
Tips - Find out which ROM version your synth has.
Factory Patches - Stored in ROM (see Manual).
Demo Sequences - Stored in ROM (see Manual).