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Chase Bit One

Programmable Polysynth

Article from Electronics & Music Maker, November 1984

Glance at the spec and you'd never know this new Italian-built and MIDI-equipped polysynth only cost £699. Paul White has the details.

The Bit One might come from an unexpected manufacturing stable, but its specification and competitive price make it difficult to ignore.

Although the Bit One is a new name in polysynths, it's been created by a European design team with many years of experience in the field of electronic musical instruments.

Although a budget-priced machine, the Bit One is a fully-equipped six-voice (two DCOs per voice) polysynth with a velocity-sensing keyboard, programmable keyboard split, 63 patch memories, and, of course, MIDI.

In common with many contemporary programmable synths, editing of sounds is accomplished not via a sea of knobs and switches but rather by entering numeric characters from a keypad corresponding to the value of the parameter being edited.


Measuring 34½" x 16" x 3¼", the Bit One enjoys the protection of a steel and aluminium case - always more reassuring than the Fablon-covered chipboard favoured by some other manufacturers I could mention. Internal construction is also to a high standard, everything being well secured and easily accessible. As the photograph shows (always assuming Stu's remembered to take the lens cap off), the circuit layout is very orderly and separate functions are located on their own PCBs, which should make for easy servicing. The main microprocessor resides on the right-hand side under the lid and the sound generation board can be seen in the base of the unit behind the keyboard. In fact, the manufacturers claim that this design incorporates two microcomputers so that the voice memories, keyboard scanning and DCO control can run efficiently.

In terms of control panel layout, the Bit One is both smartly arranged and ergonomically sound, which is a good thing, and no fewer than eight seven-segment LED displays show the patches in use and the parameter address and value when the machine is in edit mode.

To the left of the front panel are the bend and modulation wheels, the former being sprung, but these are located one above the other at the end of the panel and above the keyboard, which could make them tricky to use.

Patches can be designated to operate on the upper or lower keyboard sections, and two sliders are incorporated so that these levels may be adjusted independently. Two further sliders are provided for fine tuning/detuning and noise, but all other communications are instigated by means of soft-touch pushbuttons, there being eight of these in total, all with built-in status LEDs.

The majority of the front panel is taken up by parameter tables for the oscillators, filters and envelope generators, so it's probably about time we turned our attention to the Bit One's back panel.

As previously intimated, the upper and lower keyboard voicings have separate outputs, these being on quarter-inch jacks at a maximum output level of 0dBm (0.775V rms): connecting only one of these results in a mono output, as opposed to the normal - and occasionally disconcerting - stereo.

Next comes the inscrutable MIDI section on five-pin DIN connectors, which is only as it should be, and it's good to see a MIDI Thru connector as well as the usual In and Out. As it stands at present, the Bit One's version of MIDI only operates on Channel 1 and can only receive - not transmit - pitch and patch information, but a software update (available towards the end of the year) will expand this feature considerably, as the instrument will then be able to handle MIDI velocity and bend information as well as being assignable to any one of 16 MIDI channels. And the even better news is that this update will be made available at no extra cost to purchasers of early versions of the Bit One.

"The Bit One proved capable of competing with the fullest-sounding Stateside synths as well as the brighter, cleaner Japanese models."

Next comes a socket marked Trigger Out, but curiously the Bit One's promotional literature says nothing about this. A couple of minutes' experimenting with a voltmeter revealed that this output sits at around five volts and drops to ground for a few tens of milliseconds whenever a key is depressed, so I'm sure someone somewhere will find a use for it.

Tape In and Out connections (for patch storage) are again on quarter-inch jacks, and a Memory Protect switch is also fitted which reduces the possibility of accidental patch erasure and/or modification.


On switching on, the Bit One enters what is known as Play mode, and this configures the synth as a conventional six-voice poly playing whichever patch is indicated by the 'lower' display: this defaults to Patch 1 at switch-on.

In this mode, the keyboard is velocity-sensitive and the current patch may be changed simply by punching in two new numbers from the keypad. As only one sound can be played at any one time in this mode, the makers have given it the rather quaint name 'monotimbic'. Perhaps it means something more in Italian.

Double mode allows the user to select any two of the 63 patches which then sound simultaneously when a key is pressed, though unsurprisingly this limits the polyphonic capability to three notes, as the six voices are being split into two groups of three and then layered.

Split mode operation (can't help thinking this is getting a bit predictable - Ed) allows the user to select his or her own breakpoint anywhere on the keyboard, and this is accomplished by pressing the key immediately to the right of the desired split point. This keystroke produces no sound, but any further playing will cause the 'lower' patch to be controlled by the keyboard below the split and the 'upper' patch by the keys above it. Again, only three notes may be played simultaneously at either side of the split point.

In both Double and Split modes, the stereo outputs carry one voice each so that different signal processing may be applied to each output, and this is particularly useful for the production of string sounds, as the Bit One has no built-in chorus unit and an external one must be patched in.

Unison mode, as you might expect, causes all the oscillators to play the same note and the slight natural detuning between notes results in a satisfyingly rich, fat sound. The Split and Double keys are dual-function switches that control the tape Save and Load operations in conjunction with the Tape button. This is a simple (and these days quite familiar) process that allows the user to compile a library of useful patches on tape which may be later read back into the machine for use as they are or for further editing.

One novel feature is the Park function which allows you to tuck away a copy of the patch you're working on so that further editing does not destroy the original. This not only means you don't have to put the sound into the patch bank until you are satisfied with it, it also enables you to compare the newly-edited sound with the original to see if you really have improved it. Definitely a bright idea.

"It has no built-in chorus, no arpeggiator, and no sequencer, and looks therefore to have been designed for keyboardists who can really play."

Each of the 12 DCOs has its own 24 dB-per-octave low-pass filter and the two LFOs can produce three different waveforms to modulate either the filters or the DCOs.


Initial listening tests were carried out via a pair of pretty decent stereo headphones connected to the appropriate socket on the Bit One's rear panel. Over that medium, the machine's factory presets sounded strong, clean and bright, but perhaps a little lacking in warmth and low-end 'oomph', for want of a better word. However, connecting the instrument up to a fully-fledged speaker system proved a revelation, as the Bit One proved capable of competing with the fullest-sounding Stateside synths as well as the brighter, cleaner Japanese models. The brass and grand piano voices are particularly impressive, and only the previously-mentioned absence of some form of onboard chorus unit prevents the Chase from generating first-class string ensemble sounds.

Each of the Bit One's DCOs is switchable to one of four octaves, with a choice of triangle, sawtooth, and pulse waveforms, and it's also possible to detune one oscillator apart from another in semitone steps over an octave.

If your playing technique is up to it, the touch-sensitive keyboard - while not being an especially striking example of its type - adds real spice and variation to your performance: not surprising when you consider that key velocity can be made to modify the timbre of a sound as well as its amplitude.

The Bit One's split/layer capability is also a real boon - something that's hard to live without once you've had the use of it for any length of time - and the option of a Unison mode is also a welcome feature. It makes lead-line work a lot more convincing.


The Bit One has no built-in chorus, no arpeggiator, and no sequencer, and looks therefore to have been designed for keyboardists who can really play. As if to underline this trend, most of the synth's 'extra' facilities are intended to aid live performance, which certainly makes a change in this age of computer-activated automation.

Mind you, further developments in the Bit One series should see a rack-mounting MIDI expander module that effectively duplicates the facilities offered by the stand-alone synth, a sound-sampling drum machine (also rack-mounted), a sequencer to run the whole system and a full-length wooden keyboard to control it in real-time. In other words, a complete MIDI-based performance system from one manufacturer.

My own personal preference would be some form of parameter control other than the digital system employed here (though the Bit One is by no means alone in using it: it's one of the reasons why so many people find the DX7 such a difficult beast to tame), since there really is no substitute for being able to hear how various synth parameters interact, but if the digital selection has been a major factor in keeping the instrument's price down - and I suspect that it has - then there can be no complaints.

So, judging the Bit One on what it is rather than what it will be or what we might like it to be, I can say that, despite a couple of odd ergonomic decisions, it's easy to use, it sounds excellent, it's extremely versatile and above all, its price is low enough to give rival manufacturers a real headache.

RRP of the Chase Bit One is £699 including VAT, and further information is obtainable from Chase Musicians, (Contact Details).

Also featuring gear in this article

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(MT Nov 86)

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Browse category: Synthesizer > Crumar

Featuring related gear

Previous Article in this issue

Emulator II

Next article in this issue

Hotlicks Tapes

Publisher: Electronics & Music Maker - Music Maker Publications (UK), Future Publishing.

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Electronics & Music Maker - Nov 1984

Gear in this article:

Synthesizer > Crumar > Bit One

Gear Tags:

Analog Synth

Review by Paul White

Previous article in this issue:

> Emulator II

Next article in this issue:

> Hotlicks Tapes

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