Dave Smith was the man behind Sequential Circuits who began to build sequencers in his bedroom in the seventies and moved onto producing the revolutionary (then) Prophet 5. This was very successful for him and the money he earnt from it was ploughed back into many other projects including a digital drum machine called Drumtracks which we reviewed about this time last year. That particular piece of equipment was definitely not built in America, but no one has told me where this one's produced. I'd guess from its price-tag that it is from the US since last year's model was listed at £950 with ostensibly more features. However, as we know, these state of the art instruments very often offer more for less within a very short time. (Perhaps it's more accurate to say they offer the same for less). Certainly TOM doesn't have as many voices as Drumtracks, but it has the facility for even more via its cartridge-port.

The TOM is a digital drum machine with a lot of unusual, but highly usable features, the most startling of which is its ability to reverse the samples of its voices. This allows us not only twice as many instrument sounds, but also very, very unusual ones as far as a drum machine is concerned. (I'm sure many people will be familiar with how a reverse cymbal sounds as in Sgt Pepper, but when you reverse other sounds like claps and toms some very weird and wonderful things happen). There are quite a few other things which our friend TOM can do, but we'll get to them all in good time. TOM, aka model 420, has eight voices which are, reading from left to right: Bass drum, snare drum, tom 1, tom 2, hi hat open, hi hat closed, crash cymbal and claps. All of which are activated by their very own square button. Simply press it and it will speak to you in drum language. Now, each of these voices can be changed in pitch, even glissando is possible, volume and position in the stereo picture.

The drum machine is encased in a very small, neat container with a minimum amount of buttons and the usual set of jack sockets and things on its back edge. To make the functions more simple to operate and understand, the controls are divided into three sections: Pattern, Song and Control. The pattern section for example, contains facilities exactly like pattern number, metronome, error correct, erase instrument etc.

Each of these functions is arranged in a vertical column with an LED next to each. To select said function we have a pair of square buttons which advance or retard us through the designations. Now, if we press the button above the Song column, an LED comes on and we move to the designations contained therein such as: song number, tempo change, volume change etc. The last is our Control section which governs control of instrument tuning, volume (from 0 to 7) and pan among others.

Pad

To the right of these columns is a calculator pad with twelve keys to select and build patterns on songs; we simply press the buttons to put the machine in gear. Above the keys are a pair of 'windows' to display information relating to voices and functions. Further to the left there's an overall volume 'pot' and a pair of tempo switches; these are designed to increase or decrease the beats-per-minute. Within the calculator pad we have another pair of INC and DEC buttons which adjust virtually all the changeable functions and parameters up or down. Immediately below these function select buttons over on the far left is the button to reverse the sounds. (It won't actually make an already-recorded-sound play backwards, but only works in real time.) The cartridge access button is also placed over on that side as is the start/stop.

That more or less takes care of the geography of the top of the unit so we'll move over to the back.

Here we find the audio output jack sockets left and right, with the former acting as a headphone socket too. Next are the MIDI sockets (Din style) which allow you to interface in and out with sequencers, drum machines, digital recorders and so on. (This MIDI capability is a 'whole other ball game'. So much so, that there's a 24 page instruction book supplied simply to enable you to get the maximum from this feature).

A MIDI equipped keyboard will expand TOM's controls so that 'on-board' or cartridge sounds can be tuned and panned. (If your synthesizer is velocity sensitive, you'll also be pleased to know that the dynamics of each sound will be controllable too.) Next to the Din sockets is a tape-out jack socket to enable us to synchronise the machine to tape. This allows you to leave your final choice of drum part until the very end — even to the mix stage if you like. This will possibly save you tracks, and also help with fidelity if you're 'bouncing' tracks around. Otherwise at the back we have lock/tape to sync to external clocks or pre-recorded pulses, trigger out to drive sequencers or electronic drum 'brains' and finally a foot switch jack. This takes an optional footswitch which will not only turn the machine on and off, it will also duplicate any of the voice buttons and fire them from a distance. Sequential Circuits also supply their esteemed customers with a transformer which connects with a 15 VAC socket in the TOM.

Besides the functions I've already mentioned, TOM has several other unique and important attributes. In the Pattern mode we have Improv, which allows patterns to be recorded which will drop in drum fills a certain percentage of the time. (This percentage is of course programmable. The higher the number the more it will occur). Stack, is a feature which allows sounds to have optimum duration, even if you hit the same button before the sample has reached the end of its cycle. It simply switches the subsequent sounds to a different available channel (TOM has only four). In the cymbals' case, with Stack selected the effect is that of several crash cymbals playing rather than one being retriggered. Stack also enables us to 'flange' sounds. It 'double tracks' any instrument; simply program it into the pattern and when it cycles through in real time hit its voice button again. (The TOM's sound generating circuitry gives a slight delay and effectively flanges the sound. However since only four voices can sound at one time we must be careful when we use flanging since it only leaves us with two other sounds playing.) Reframe allows us to start wherever we like within a pattern, not just at its natural beginning. Another useful function of the Pattern section is Copy/Append to which allows us to copy a pattern, store the original, and do edit work on the copy. (This way a mistake will not mean you have to 'go back to the drawing board').

The Song column has something called Sub-song which is no different to a normal song except it can't be 'looped'. Once Sub-song finishes playing the TOM moves on to the next pattern. Sub-song is also useful for tempo change and a very convenient aid to programming. Looping by the way is designed to save memory, it runs round a pattern as many times as you specify before moving to the next step in the song. Tempo and Volume change are also in the Song section. They do what you'd expect them to and we have 7 degrees of volume and the Tempo can be varied from 40 to 240 bpm. Human factor will only work on Song, it changes slightly the pitches and volumes as the machine plays.

The Control column has such things as Instrument tuning and Volume as well as Pan and Auto repeat. This one allows instruments to be played at a steady rate and is directly linked to error correct (which is the quantize feature of TOM). So, if you want to play a hi hat into the memory instead of hitting the button many times we simply hold down the repeat. Error correct works from 2 up to 96 so we can have our hi hat (say) sounding 16 beats to the bar with a clap playing 12. So we can easily build up polyrhythms. As you can appreciate 96 is very fast so we can use it to build tom rolls (or any roll for that matter) and we can persuade the TOM to get progressively more (or less) dynamic through the roll. We can also make it change pitch like a Timpani.

Sounds

Actually I was not too dissatisfied with the quality of the voices. As per usual, the 'crash' cymbal had a little too much gong in the middle pitches, but was better at the upper and lower ends of the scale. The bass drum was good and thumpy but I found the unadulterated toms just a little flat without echo. Because we have only left and right output we have a slight problem with 'effecting' single voices. The best we can do is put all voices which we wish to echo (or whatever) to one side of the stereo picture. Normally one would be justifiably dis-satisfied with a drum machine at this price which didn't have individual outputs for all its voices. But, the TOM seems to give you so much control that it doesn't matter so much. The hi-hat has a very fine sound whether open or closed.

Of course you have all the facilities of the normal machine like Insert, Delete, Erase, and Metronome, but TOM also has Truncate which will remove anything you don't want without necessitating a complete rewrite. In common with most of the other products on the market you can save memory by 'dumping' patterns to tape and return the data when you need it. (There's a verify function to let you know that you've accomplished that feat.) As far as familiarity is concerned a synth player and I mastered all but the most complicated manoeuvres without too much recourse to the instructions.

All in all I'm impressed. TOM would appear to be the first drum-machine programmed with the modern sound and facilities that 1985 musicians need. It's a shame that it does not have individual outputs. I must say I can't understand why they'd omit them on a piece of equipment at this price.

For: Facility to reverse voices, repeat function, MIDI re-frame, humaniser
Against: Only stereo output, price

SEQUENTIAL CIRCUITS TOM - RRP: £860

Thanks to the London Rock Shop for the loan sample.