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Korg CR4

Cassette Multitracker By Tom Flint
Published November 2004

Korg CR4Photo: Mark Ewing

Korg, one of the main manufacturers of digital workstations, have just released another multitracker, but this time it's cassette-based.

The first multitrack owned by many of us of a certain age was a cassette four-track, but when digital recorders came along, bringing with them digital editing, mix recall, automation, and noise-free recording, it seemed as though tape had had its day. Indeed, digital has made high-quality recording a possibility for the home studio owner in a way that the compact cassette could never do.

Yet despite the growth and development of the digital recorder market over the last decade, cassette-based multitrack machines have soldiered on surprisingly well, and, as Korg have demonstrated with the release of the CR4, some of the big names in the industry are still prepared to spend time and money developing new cassette-based products.

So why would you choose to buy a cassette multitracker these days? Well, it wouldn't be your first choice for making release-quality recordings, because of tape's inherently high level of noise, but for creating rough demos, or for the purpose of jotting down musical ideas in a simple and immediate way, such machines do have their place. Compact cassettes are still a very cheap recording medium, they can be bought just about anywhere, they're easy to use, pretty reliable, and very robust — shake a cassette as hard as you like, for example, but it's still unlikely to lose data or become corrupted! Even the most technically minded musicians covet immediacy when they are in creative flow, so being able to plug in and record without worrying about data integrity or software routing issues is still very attractive.

What Do You Get?

Although Korg have called the CR4 a four-track cassette recorder, in offers both more and less than that title suggests. The extra features it brings to the table are the pair of built-in speakers and Korg's own Ampworks modelling processor and multi-effects. Used in combination, the speakers and modelling effects allow the CR4 to be used as a practice amp for guitarists, bassists, and vocalists. It can also act as a modelling preamp or DI device. For example, if a guitar lead is plugged into one of the inputs, an amp simulation can be applied, as can an effect, and the resulting signal can be output into a separate recorder.

Absent from the CR4, however, are any real mixing facilities. True, the four tracks can be panned and mixed to make a stereo signal, but that's about it. The CR4 can't internally bounce tracks, it cannot apply effects or processing to recorded material, and it has very limited monitoring facilities. It also lacks a varispeed control, which I always felt was one of the best things tape offered to the creative musician.

At the top of the front panel is a counter and reset button, although the CR4 has no 'zero return' facility. Underneath the tape mechanism are six standard transport buttons, including the all-important Record, which can only operate when a tape with unbroken write-protect tabs is loaded. Under the Pause button is an LED indicating whether power is on, plus four further metering LEDs showing the output signal level. Below these is a master level control for adjusting the line output, speaker, and headphone volume levels.Korg CR4Photo: Mark Ewing

The remaining controls that are situated between the two speakers are shared between the four recordable tracks. Every channel has its own fader, Pan knob, track-arming button, and Trim control, with dedicated overload LED. The track-arming buttons also have their own LEDs which flash green when they are selected for recording, stay green during recording, and turn red when a signal overloads the tape. There is also an Effect button for each channel, and these buttons enable the CR4's internal processor to be applied to a particular input source.

Signals are input channel by channel via four quarter-inch jack sockets mounted on the front edge of the machine. To the left of the inputs are Main and Sub headphone sockets. It's a nice to be able to use two sets of phones with such a budget machine. Inserting a headphone lead into the one labelled Main cuts the signal to the speakers, and the Sub socket remains inactive unless the Main socket is in use. There is also a dedicated speaker on/off switch on the back panel. The speakers themselves have 8cm drivers, are of the bass reflex type and deliver 2.5W each. The cones are protected by sturdy metal grills, which also prevent guitar picks and bits of food from vanishing inside the vents! The remaining back panel features are the left and right Line Out phonos, the input for the 12V power adaptor (included with the CR4), and the master power button.

Bouncing Back

The CR4 doesn't have a bussing system, which means that its recording options are fairly restricted. In the past, many four-track recorders actually made it possible to record up to 10 separate tracks using just one machine. This was done by recording on the first three tracks and then bouncing them to the remaining track together with one further part played live through the fourth channel input. New parts would then be recorded onto tracks one and two, which would then be bounced to track three together with another live part. The final bounce would require a new part to be recorded on track one, and then bounced to track two, together with yet another live part. That would leave track one available for recording the tenth track.

Although the CR4 is probably not intended for serious multitracking, some sort of bussing system would have been welcome, even if it just allowed the four inputs to be mixed to a single record track. As it is, the manual suggests bouncing down to a second stereo recorder and then feeding the resulting tracks back to the CR4 ready for overdub. While this is a possibility, it does require the use of a second machine, and that idea conflicts with the all-in-one character of the CR4.

Modelling Effects Processor

One of the CR4's big selling points will surely be the inclusion of Korg's Ampworks effects and REMS (Resonant structure and Electronic circuit Modelling System) proprietary modelling technology. Both effects and models are available to a recording channel when the relevant Effects button is pressed, although they can only be used by one track at a time. Two rotary dials, one labelled Modelling and the other Effects, provide a limited but carefully chosen selection of treatments.

The eleven presets available on the Effect dial are Comp, Wah, Chorus, Flanger, Phaser, Trem, Rotary, Delay, Reverb, Cho+Dl (chorus and delay) and Cho+Rv (chorus and reverb). Although there is no way to access all the parameters of each effects patch, the CR4 does offer a Tap button for setting the modulation speed of many of the effects and the decay time of the Reverb algorithm. None of the compressor's parameters can be changed by the Tap button, and the sweep speed of the wah-wah is also uneditable. Nevertheless, the up/down direction of the filter sweeps can be set by adjusting the Effect Depth control.

The CR4's Modelling dial offers a selection of eleven preamp and processor emulations. Amongst these are two bass-amp models, named Valve and LA Studio, plus two models designed specifically for vocals. Vocal 1 is tantalisingly described as a 'widely used Austrian condenser microphone sound', while Vocal 2 is supposedly 'a standard dynamic microphone' model.

Korg CR4Photo: Mark Ewing

Some of the guitar amp models are also named slightly cryptically. For example, we are told that the UK '80s is modelled on a UK-manufactured 100W master-volume head from 1983 — there are clearly some legal issues preventing Korg from naming some of the products these models have been based on! The labelling of the AC30TB model is not quite so cryptic, however, and the manual states that it is the classic Vox AC30's Brilliant channel. Overall, the amp models are quite a well-chosen bunch, ranging from the clean, such as the Btq Cln, to the very dirty, demonstrated best by the Nu Metal option, and they should be enough to please most of the people most of the time.

The Ampworks section's set of six rotary knobs work in conjunction with the modelling algorithms and effects. The three centre controls are labelled Treble, Middle, and Bass and provide a three-band EQ section as one might find on a guitar amp. The Volume knob simply adjusts the amp level and the Mid-FC/Gain alters its gain, although if a clean model has been selected (such as Vocal 1/2, Valve, LA Studio, or Ac EQ) this control sweeps the mid-band. The remaining knob, labelled Effect Depth adjusts the level of the effects processor, although it can also be used to set the threshold of the internal noise gate (see the Noise Reduction box), and, as explained above, operates as an up/down selector for the wah-wah effect.

Noise Reduction

The Ampworks effects section has what Korg call a 'noise-reduction system' which actually turns out to be a variable noise gate. Its threshold can be set by holding down the tap button and then adjusting the Eff Depth control to the appropriate level. There is no LED to indicate the status of the gate, so a little trial and error is necessary when setting it up. Thankfully, doing so is quick and easy, so it doesn't take long to find a suitable level. Unfortunately there is no noise-reduction system for reducing the recorder's tape hiss.

The CR4 In Use

As you would hope, the CR4 is easy to use, which will suit those who just want to concentrate on the process of getting their ideas on tape with the minimum of fuss. Loading a tape is just a matter of lifting the plastic lid and clicking the tape in place. Standard compact cassettes of any kind can be used, although the manual recommends using high-bias type-II chromium dioxide tapes of less than 60 minutes in length.

To record, simply plug in a guitar, microphone, or whatever, set the Trim pot so that the associated red LED doesn't flicker too much, and then raise the channel and master faders until you have a comfortable monitoring level. The position of the channel fader affects the level of the recording, so this needs to be set as high as possible, and the second channel overload LED gives a fair indication of the optimum level. The master LEDs do not represent the recording level at all, and any overload shown here relates to the output level only.

Korg CR4Photo: Mark Ewing

If effects processing is required, this can be selected instantly by pressing the channel Effect button. The amp models are easily applied, and the control knobs allow the desired adjustments to be made directly. The gain control and EQ really do react like the knobs on a real guitar amp. Similarly, using the Tap button to adjust the effects couldn't be easier.

Although the CR4's simplicity is to be commended, there are some aspects of its design which would really have benefited from being developed a little further. For example, it's a shame that the Ampworks models and effects are only available when recording, and can't be used on a pre-recorded track. I can't imagine that it would be too difficult for Korg to include a switch to insert the models and effects into a channel on mixdown, or even to place them across the stereo output buss. Having more flexible effects routing would mean that, for example, a guitarist could lay down a rough idea, and decide on exactly how much processing to use at a later date.

Multitrackers of old rarely, if ever, had the luxury of built-in effects, but they usually provided an effects send-return loop, so external processors could be used. Given that this recorder cannot use its own effects on mixdown, such a facility would have been a welcome addition here. It's also annoying that the EQ is wholly part of the Ampworks section, and cannot be used to treat the mixed signal. Once again, if the effects could be applied to the stereo mix, then the EQ would expand the CR4's feature set significantly.


Korg have produced a rather unusual product, which, given its limitations as a recording device — it suffers, of course, from tape hiss — will probably only be used as a portable notepad or very rough demo recorder. Fortunately, many of the reasons why someone might want this product have little to do with multitrack recording as such. I think a better description of the CR4 would be 'guitar, bass, and vocal practice amp/DI with modelling effects and a built-in four-track recorder' — although that might look just a little bit messy printed on the box!

This is a no-nonsense product which does a limited number of things simply and effectively, so the use of the compact-cassette format is quite understandable. For example, compared to hard drives, which are easily damaged and need to be backed up regularly, tapes are extremely robust and damage resistant. So much so that, even after a dodgy tape mechanism has chewed up a segment of tape, the recording can usually be rescued. I can imagine bands dragging the CR4 along to their practice sessions or taking it along with them on the road, or even musicians with sophisticated studios using it to jot down ideas quickly before booting up the rest of the studio gear.

I'm not quite sure why the CR4 has two speakers, though. They are so close together that they don't really provide a stereo image, and for a practice amp two speakers are unnecessary. I would have preferred it if Korg had sacrificed one of the speakers and used the resulting panel space and budget to add some more features. Alternatively, a single larger speaker could have been installed, which would have benefited the bass end, and would therefore have made the CR4 a more useful practice amp for bassists, guitarists and vocalists alike.

On the other hand, I can appreciate that physics may have affected the CR4's design. It might be possible to damage a recording by placing a cassette too near a speaker magnet. Furthermore excessive vibrations from a powerful speaker could cause problems by shaking the tape mechanism.

In terms of price, the CR4 represents reasonable value in the UK, given that the product is a practice amp, modelling DI device, and four-track recorder in one. For the same price there are better products available in each of those market areas, but I can't immediately think of anything else that brings together the same features into one product. The CR4 is a little mad, occasionally flawed, but an interesting product nonetheless, and it's sure to be just the thing that a few people have been waiting for.


  • Makes a nice practice amp and DI.
  • Very portable.
  • A great way to demo ideas.
  • Two headphone sockets.


  • The effects and amp models are only available on one channel at a time.
  • The Ampworks effects cannot be used on recorded tracks or on the full mix.
  • No tape varispeed.
  • No system to reduce tape hiss.
  • No internal or external effects loop.


The CR4 is an unusual product which has been designed to fill a small niche in the market. As a four-track cassette multitracker, the machine is very basic, but it also functions well as a practice amp and as an input device for guitars, bass, and vocals.


£199 Including VAT.

Korg UK Brochure Line +44 (0)1908 857150.