Hybrid Arts ADAP
Computer Sampling System
Sampling keyboards are everywhere this year, but most of them are confined to 12-bit resolution. Our US Editor, Rick Davies, gets a taste of 16-bit sampling with an incredibly cheap Atari-based system.
Just when 12-bit sampling systems were becoming the norm, Hybrid Arts come up with an economic 16-bit system based on Atari ST computers.
WHAT THE ADAP does is far more than simply sample and play back any audio source you can find. It also provides an assortment of cut and paste-style editing tools which can rearrange passages of music or dialogue into any shape you can imagine; provides two channels of digital audio so that each channel can be edited independently of the other; and provides flexible conversion facilities which allow samples to be downloaded to digital audio equipment using the standard 48kHz sample rate, or to MIDI-equipped samplers implementing the MIDI Common Sample Dump Standard format. Not exactly run-of-the-mill features, those.
Since the ADAP's sample quality is as good as just about anything else on the market, its flexibility lends itself to editing short musical passages with accompanying dialogue, editing and filing of samples which can be dumped to other samplers as required, as well as the standard application as a musical instrument.
The back panel of the ADAP rack is simple enough - though that simplicity may not be to its advantage. There are two inputs, two outputs, an input level control, and a power connector and switch, But the demand for individual outputs on sampling instruments has been made clear over the past few years, and the stereo outputs on the ADAP may well be viewed as insufficient for many of the applications engineers and musicians will doubtless conjure up.
The ribbon connector between the rack and the ST is the 16-bit parallel pipeline that enables the ST to control and access the rack's conversion hardware. Beyond outside appearances, this system bears no resemblance to other computer-based sample-editing systems, because the rack cannot do anything without the ST, which co-ordinates everything - from the response to incoming MIDI data to the routing of the audio sources to the audio outputs.
AT SOME POINT, it's necessary to consider the pros and cons of a system such as this one, and specifically, how it compares with dedicated sampling instruments.
First of all, there is the question of sound quality. The ADAP can sample at 44kHz, 22kHz, 11kHz or 48kHz in stereo or monophonic. As usual, the sample rate affects the amount of available sample time. Less usually, it also affects the number of notes that can be played simultaneously. For example, at 44kHz sample rate, a 1040 ST-based ADAP system can sample 20 seconds of mono audio (10 seconds stereo), and later play back with six-note polyphony. At the 22kHz sample rate, however, the sample length doubles, and 14-voice polyphony is possible.
This is a unique trade-off to my knowledge, and should be a popular one at that. One of the ways that the ADAP is able to pull this off is by not having VCFs on each voice, as is typical of most instruments with a fixed number of voices. This means there are no filter sweeps available, but the ADAP's digital EQ should help tailor the tone of your samples to some degree.
In its finished production form, the ADAP will be able to hold 64 multi-samples (sample time allowing), playable over MIDI by various controllers. (Unfortunately, the prototype I looked at did not yet have the ADAP's entire MIDI specification implemented.) Again, the dynamic voice allocation helps the samples to get out in an orderly fashion, but is alas probably responsible, in part at least, for the two-output limit.
"You select either the left or the right digital audio channel for editing; imagine a stereo sample having one channel looping while the other plays backwards."
If separate processing of each sample is the major concern, then the ADAP's internal digital effects "rack" should help compensate for the lack of individual outputs. In the "rack" portion of the program, the screen displays five spaces in which you can place effects such as delay or reverb. These programmable effects are merely algorithms which may be applied to samples upon playback which affect the sample data, rather than the final analogue audio signal. Better still, samples can be stored on disk in processed form.
ADAP will be available with reverb and delay effects as standard, leaving three additional "rack spaces" for other effects which may be purchased on separate disks. It'll certainly be interesting to see how these internal effects compare with conventional treatments when the ADAP is in production.
The central element of the ADAP program is the Command screen, from which you select functions using the ST's mouse. This screen also displays a portion of the sample currently under examination, and lets you hone in on the desired section with "Zoom-In" and "Zoom-Out" functions. Also on this menu are the various "cut and paste" functions, as well as sample reverse and looping facilities.
This menu is also where you select either the left or right digital audio channel for editing. Think about this for a minute: this could lead to some truly off-the-wall sounds. Imagine a stereo sample having one channel looping while the other plays backwards... An extreme application? Certainly. Fun? Absolutely.
An oscilloscope function allows you to monitor the audio inputs in real-time with eight-bit resolution (the screen graphics require too much of the ST processor's time to allow better resolution).
This brings us to the matter of sample storage. Files are saved to disk using graphics programs, and each 3½" disk can store one full 1040ST memory. The addition of a hard disk to the system allows storage of 30 files, and would also speed up the loading time considerably.
If desired, these files could be transferred over the Atari's serial interface with little fuss, allowing other digital audio systems to use the data.
Wendell Brown, President of Nilford Laboratories, who co-developed ADAP, has indicated that they intend to use a sample file header in the same format as the one used by Digidesign's Sound Designer files, so that files can be swapped between the two systems.
Similarly, should an ADAP system be joined by a sampler which uses the MIDI Common Sample Dump Standard Format, samples could be transferred back and forth as desired.
ALL IN ALL, the ADAP strikes me as an impressive and rather clever way of getting the best musical use out of contemporary computer technology. The sound quality, sample editing features, and attention to detail look extremely promising, and considering the price, it's excellent value - even with the additional cost of the ST computer which, needless to say, would obviously come in useful for other things as well.
Since the system's performance is dependent on software, and software can be updated, ADAP could have a much longer useful (no, make that "competitive") working life than some dedicated sampling machines. Several different versions of the ADAP system - with varying specifications - are being discussed at the moment, and although the structure has not yet been finalised, the potential is clearly huge.
With luck, the ADAP's multiple personality will not confuse many people. It may not replace dedicated sampling instruments in all situations, but it's certainly working in new territory without losing its footing in more common areas. It will be interesting to see with which other areas of digital signal processing the ADAP will deal. In time, of course.
Price To be announced
Review by Rick Davies
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