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Audio Technica AT-RMX64

Multitrack Cassette Recorder

Neville Unwin puts this sophisticated home studio package through its paces.

All the convenience of a cassette based multi-tracker with the flexibility and sophistication of a true mixer based system.

Cassette multitrack recorders have been on the market ever since Tacsam brought out their 144 Portastudio as long ago as 1980. Recently, however, there has been a sudden and increasing interest in the medium. At the APRS show last month, much interest was shown in the new multitrackers shortly to be made available and several of these products will be reviewed in HSR in the near future including a further offering from Audio Technica named the Teczon; a much smaller 4-track machine. Moreover, cassette multitrackers seem to be moving up-market. This latest model from Audio Technica has six mixer channels (as opposed to the usual four) and many additional features not usually found on machines of this type, that puts it in a different league to most of its would be competitors. In purely physical terms, however, this is simply the largest and heaviest cassette multitracker I've come across, which tends to move the emphasis away from the word portable.

In the Flesh

The mixer is a 6 into 4 affair, with the six incoming channels located to the right of the machine. Unlike many other recorders this model offers the facility for simultaneous recording on all four channels. Input sockets are situated on the back panel and comprise two ¼" inch jack inputs and an XLR socket for each channel. There is the option of having 48volt phantom powering on the mic inputs which is very unusual on a product of this kind.

On the channels themselves, the incoming signal is regulated by an input gain pot, and you're warned when the input is overloading by a red LED that lights up just above this control at the onset of clipping. Greater flexibility regarding the matching of the input level is given by a switch that selects either -20dB, 0dB or tape input sensitivity and there are two auxiliary send gain controls for each channel which are routed to the appropriate sockets on the back panel and each send bus may be switched to operate pre- or post-fade/EQ. Two return channels are also provided for the connection to the outputs of external effects processors such as reverb or echo.

The unit also features a detailed EQ department. The pots controlling the EQ (two dual-concentrics for each channel) are marked High and Low and operate much in the manner of conventional bass and treble controls. The high frequency pot has a shelving/peak-dip switch and the low frequency one a high pass/peak-dip switch. Additionally, the frequency range of the EQ may be swept over its entire range using the dual concentric pot system so you really do get the best of both worlds. The low frequency pot covers the range 60Hz to 1.5kHz, and the high frequency pot's range overlaps with it, being 600Hz to 10kHz, and thereby ensures that a reasonable degree of control is possible over the entire audio frequency range. All in all, the EQ section is comparatively sophisticated for a cassette based system and the option of being able to select peaking or shelving EQ profiles is a valuable one adding greatly to the tonal flexibility of the unit.

The Aux Send and EQ sections.

The sub-assign buttons, that route the input channels to any of the four tracks of the cassette, are mounted directly below the EQ section, and this is where the gaudy, if logical system of colour coding becomes most evident. The white, green, orange, and pink track assign buttons combined with the blue EQ pots, orange input gain controls and red and green LEDs give the unit an appearance almost but not entirely quite unlike a box of liquorice all-sorts.

"All in all the EQ section is comparatively sophisticated for a cassette based system."

In addition each channel has a prefade solo switch that enables that channel alone to be heard which is invaluable if you need to scrutinize a single sound source without being distracted by the rest of the mix. The solo buss is monitored by a green, yellow and red seven segment LED level meter situated next to the VU meters on the top panel which is a further useful aid to optimising the settings of the input gain controls or any return or sub output.

To the right of the six input channels, are the two return channels for the effects. Although they do not have faders of their own, they can be assigned to any of the six input channel faders via the two relevant routing switches and they do have their own gain/pan dual concentric pots, solo buttons and track assign switches, that function in the same way as those on the input channels. Directly below these return channels are the faders and solo buttons that control the four cassette tracks. Monitoring of these tracks through headphones is made possible by a pair of stereo headphone sockets on the front of the machine and a duplicate set on the rear panel. It's also possible to choose whether to monitor all tracks, tracks one and two or just one solo track.

A VU meter is provided for each tape track and may be switched to monitor the signal going onto tape or the signal coming off tape.

For actual recording, there is a level control that affects what finally goes down on to the tape for each channel as well as a pushbutton for each track that enables the record mode and a red LED reminds you that the channel is 'ready'. Two tape speeds are available; 3¾ ips and 1⅞ ips, and in addition there is a variable pitch control that slightly speeds or slows the cassette, producing a resulting rise or fall in the overall pitch. This comes in handy if you come to overdub an instrument that is not quite in tune with the instruments already recorded as you can in effect tune the recorder. As you would expect, all the conventional controls of a cassette recorder are there, with the inclusion of a 'Return to Zero' function.

Both Dolby B and C noise reduction are featured and are accessed by two pushbuttons to the right of the cassette recorder section. Dolby C is arguably the best type of noise reduction to use with cassettes as it offers a good compromise between improved signal to noise levels and undesirable side effects but the inclusion of Dolby B means that you can play your old pre-recorded tapes without any problems. All in all, the RMX64 showed quite an impressive range of facilities that appear to have been well thought out by designers who know something about the way their product is likely to be used.

"There's no getting away from the fact that this is very expensive for a cassette multitracker..."

Round the Back

The back panel.

On the back panel, there are a large number of inputs and outputs including both unbalanced jack sockets and balanced XLR sockets for the mic inputs. Each channel also has a send input and output (or insert point) for patching in effects units that can be used on individual channels in addition to anything that might be connected via the auxiliary send system. There are also four phono tape outputs provided, enabling the unit to be used with a separate mixing system, and the two pairs of headphone outs allow monitoring of the separate tracks of the recorder. Furthermore, sub outs with jack, phono and XLR connections are also included. None of the sockets on the back panel protrude far enough to be in danger of being damaged, and the power switch and two Amp fuse are also suitably recessed, (as are the faders on the top panel). Audio Technica have precluded accidents of this kind by making the side panels of the recorder overlap slightly on the front and back of the recorder - rather like some of the older styled synthesisers, but in a less exaggerated form. However, these do contribute rather heavily to the overall weight, which as I have mentioned is, at nearly 50 pounds, somewhat heavier than the average cassette multitracker and heavier than some reel-to-reel machines I've used.

Road Test

This is a three motor tape transport with full solenoid transport controls which means in practice, smooth operation in both play and fast wind modes. The soft touch controls are similar in operation and feel to those fitted to hi-fi cassette decks and make a welcome change from the clunky lever controls provided by some cheaper machines. Once you've got used to the layout and routing, this is a very simple and logical machine to use and the comprehensive monitoring system means that you can check on any signal levels throughout the signal path with the minimum of fuss. When using the EQ section to any extent, you will appreciate the extra control that it offers when compared to a fixed bass and treble control arrangement but you do have to experiment a little before you can get the best out of it. The Dolby C setting gives the most effective noise reduction both in terms of signal clarity and lack of hiss as indeed it should and it is possible to get away with a quite a few track bounces before noise becomes a problem. I wouldn't like to say just how many bounces you can get away with as I'm a reel to reel man and consequently very fussy but it's certainly as good as any other cassette multitrack recorder in this respect when used at the higher tape speed. An added benefit of this type of noise reduction system is that it doesn't unduly affect percussive sounds compared to the performance of some compander based noise reduction systems, a side effect which generally becomes even more noticeable as the heads wear.

An RMX64 taking quiet a nap in the shade of a silver birch.

Dropping or punching in can be accomplished by using the transport controls or by means of an optional footswitch and this is click free as you would expect on a unit of this calibre. It is though advisable to punch in or out on a beat to mask any discontinuities in the sound and don't forget that dropping out always leaves a short gap due to the distance between the erase and record heads.

The overall sound quality was well up to scratch for a cassette based unit but you do have to use good quality, preferably new tapes if problems are to be avoided and, as with any tape recorder, you must clean the heads regularly to prevent oxide build up which dulls the sound and accelerates head wear.


With so many new cassette based systems being released recently, it's inevitable that competition will be fairly intense, but with this particular machine, it seems that Audio Technica have aimed at the very top end of the multitrack cassette recording market. The overall facilities of the unit are much more comprehensive than those offered by most units, particularly the versatile and useful EQ section and the good range of output facilities, not to mention phantom powering. All this comes at a price however, - £1099. There's no getting away from the fact that this is relatively expensive for a cassette multitracker, even for one as versatile and well thought out as this. This unit may well find itself under heavy competition from somewhat less sophisticated but much cheaper models and the new Tascam 246 will be it's strongest rival in terms of price and facilities. Many may even feel it worth the slightly extra expense involved in going for a cheap reel to reel recorder and a small second hand mixer, rather than paying a not dissimilar amount for a cassette machine. This is without any doubt the main drawback of the RMX64, which in itself is a very adaptable and versatile machine, and ideal for bridging the gap between a small cassette multitracker and a full sized reel to reel recorder with mixing desk. However, in it's favour, many people are reluctant to forego the undeniable convenience of a cassette based system and it is to those people that this type of machine will appeal, especially the ones who want the best in the way of performance. There should be enough people in that category to ensure that the Audio-Technica RMX64 finds a firm foothold in the market place.

Further information is available from John Hornby Skewes, (Contact Details).

Also featuring gear in this article

Previous Article in this issue

Vesta Kozo DIG411 Digital Delay

Next article in this issue

Getting Strung Up

Home & Studio Recording - Copyright: Music Maker Publications (UK), Future Publishing.


Home & Studio Recording - Oct 1985

Donated & scanned by: Mike Gorman

Review by Neville Unwin

Previous article in this issue:

> Vesta Kozo DIG411 Digital De...

Next article in this issue:

> Getting Strung Up

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