Review: Korg MR-1 Hi-Def Portable Recorder
Pages: 1, 2, 3, 4

So, if more bits are better, why is Korg's 1-bit technology a step forward? In a nutshell, 1-bit technology is to digital audio what RAW is to photography. Instead of rounding the audio level to 16 or 24 bits and filtering, which naturally produces distortion, it uses the single bit simply to describe whether the level of each sample is higher or lower than the previous one. Paired with a sampling rate of 2.8224MHz (64 times the CD rate), this technique can produce a significantly purer sound. Korg's MR-1000 boosts the rate even further, to 5.6448MHz.

This diagram from Korg shows how 1-bit recording (bottom) avoids the distortion from filtering and roundoffs in PCM recording. (Click to enlarge.)

Incidentally, you may be wondering how this 0-or-1 system represents a signal that's neither going up nor down. According to Korg, the sampling rate is so high that constant levels can be represented accurately by an alternating stream of 1's and 0's.

The technology has actually been around for quite some time; it's used for Super Audio CDs (SACDs). If you are truly curious, take a moment to read Korg's white paper, "Future Proof Recording Explained" (PDF). Even better, check out this video of Korg's Jerry Kovarsky explaining it at the AES Convention.

Once again, it was off to Hawaii for some fiery field recording.

The Field Test

As luck would have it, my review unit arrived as I was leaving on yet another trip to Hawaii, where I'd reviewed the previous three digital recorders in this series. I popped open the box, tossed the recorder in my carry-on, and headed for the airport.

The first thing I noticed was how easy the MR-1 is to use. Hit the large slider to power it up, and then use the Menu Button and P-dial (a multifunction wheel) to navigate and make selections. All the necessary transport functions are conveniently located on the front panel. No matter where you are in the menus, pressing "Record" arms the unit and brings up the meter screen. It is so well laid out that I was recording before I cracked the manual!

A pair of balanced/unbalanced 1/8" inputs handles a variety of levels. (See spec chart.) Although Korg supplies a wiring diagram so you can solder your own mic cables, I wish they had included adapters. But, as I said, the bundled single-point stereo mic is first rate. Here is a recording I did while checking out a friend's luau band. It's crunched down to MP3 for Web playback, of course, but you can get an idea of the spaciousness.

• Luau Recording, T-Mic (504KB MP3)

I also made some tests outdoors while at the Aloha Music Camp; alas, the lack of a windscreen ruined most of the recordings. This is the second field recorder I have tested that did not include such a basic element.

The MR-1 distorted while recording loud bagpipes and sax.

With no clipping indicators, it is easy to overload the MR-1's preamps, as I discovered the hard way when recording a bagpipe and saxophone ensemble:

• Bagpipe and Sax (464KB MP3)

The mic/line switch functions as a "pad" for lowering excessively loud signals. That's handy, though not intuitive. One more reason to read the manual!

Each input supplies switchable +3V phantom power for mini-microphones; you will need your own power for studio-grade condenser mics. You set levels via submerged menus. Bummer, but at least the meter screen pops up with a single press on the P-dial when the MR-1 is record-ready. Did I mention the lack of clip lights?

The MR-1 is extremely easy to operate. On the far side is a data wheel for navigating menus.

Korg thoughtfully incorporated a fair amount of control into the Auto-Gain settings. (Auto-Gain is simply a dynamics processor inserted in the signal chain to level out the differences in loud and soft signals.) In many small recorders, automatic gain control is either on or off, and the results are anything but subtle. Although the effect here is not 100% transparent, the MR-1 is one of the few recorders on which I would consider using this feature. Perhaps it would have saved my bagpipe recording from distorting.