Cheetah Sound Sampler

The following reviewt was taken from ZX Computing Novemebr 1986

Sound sampling has become the "in" thing in the music field at the moment due to recent developments in technology and, since it is a computer based technique it is not surprising that such a device should be developed for our home micros.

To put it rather simply, sound sampling involves making a digital recording of a voice instrument, piece of music or some other sound, processing it as required and replaying it in a choice of pitches.

The Cheetah sampling system consists of an interface, software cassette and microphone. The interface connects to the port at the back of the Spectrum (48K, Plus or 128) and has two control dials on the front, a mini jack sound input socket on the left hand side and a six foot lead fitted with a phono plug to take the output
to an amplifier or stereo system. There is a problem in that the lead is not really long enough and the phono plug is only suitable for stereo or expensive mixing desks. The more usual plug is a standard jack, and it might have been better if the control knobs had been positioned on the top and a second socket had been fitted for output.

The microphone is a fairly basic one for use with a portable cassette recorder and is not really suitable for serious use.

Although a Microdrive backup routine is supplied, there is a dire warning not to use the interface with anything other than another Cheetah Unit.

Tech specs

The specifications are impressive, replay over two octaves, superb processing allowing very fine selection of start and end points to be made and sustain start and end points. These are chosen on a graphic waveform display. Samples can be reversed or combined, saved or loaded and reconfigured at will.

The frequency or bandwidth is 17.5KHz and this is as good as you'll get on some dedicated samplers for many times the money. Sample rate is 70000 times a second and maximum length is around one second. Which is long enough to say your name or a simple Nineteen!

The utility or effects program is great for playing around with, providing echo reverb fuzz, chop bubble and pitch effects, very noisy though and there's not enough control for serious usage.

Usability

The publicity claims "Home or Professional" use and I wouldn't disagree All I would say is that the professional use may be rather limited, especially if it was intend6d for recording as the sound quality is good rather than excellent, and the background noise is rather too high for professional standards even under optimum conditions.

The input section is well designed, allowing a wide range of impedences from microphone line or instrument sources and the output match proved compatible with both my power amp and my cassette line in.

Operating the sampler is a joy. Everything is menu driven and error trapping seems to be very comprehensive even with my idiot act in full swing it informed me of where and why I had gone wrong each time.

I loved it, even at the level of simply playing around it was great. I took it into a local school and the pupils had a great time with the utility program and the Science teacher was devising ways of using it for the new GCSE exams

Finally I have spent quite some time using the sampler, and I am becoming more and more impressed with it. I would even cautiously suggest that a studio might be able to use it for some short and limited effects provided enough noise reduction was available.

The following review was taken from Sinclair User November 1986

Maybe Cheetah has missed the boat. The sound sampler its recently released will inevitably be compared to the Ram Music Machine.

Rams unit combines a sampler, MIDI, and built in software and the Cheetah Sampler costs about the same, has no software built-in and lacks MIDI.

Does it stand a chance? Well, maybe.

If you’re any sort of serious musician perhaps with existing MIDI gear it’s very doubtful that the Cheetah package will have much to offer when compared with the MIDI-compatible Ram system.
On the other hand if your interest in sampling is less serious and you just like the idea of making strange and/or silly noises and fiddling around with your voice then as sampler pure-and-simple this Cheetah package might just be a better bet.

What you get is a black joystick-interface-sized unit which fits on to the Spectrum edge connector. Also supplied is a microphone which connects into one side of the unit. There is another lead which connects from the unit into the back of a hi-fi system (it ends in a phono plug so if your hi-fi uses DIN then you’ll need a new plug).
If you haven’t got a hi-fi an alternative is to buy an adapter (phono to mini-jack) and connect the thing into the mic socket of your cassette player. The quality won’t be anything like as good however.
So you play your sound into the microphone where the black box samples it - effectively it gets digitised. Then you change it, twist it, cut it up - whatever you want - and play it back at a different speed or pitch through the hi-fi or cassette player amp.

A single tape contains all the driving software for the system. There’s the sound sampler itself, a number of digitally-encoded test Samples including a bell (that old standby) and someone saying ‘hello’. The final program on the tape is a real-time sound utility program, of which more in a moment.

The sampler software is at the same time both sophisticated and awkward. One of its many features is a volume level check facility that allows you to adjust the volume levels exactly for the best possible sampling - it works by producing a graph of the volume of input, if the peaks of the graph waves are just contained within the screen volume level is good, if the peaks are ‘clipped’ then you will start loosing sound quality.
You can actually get your sound into the machine in two ways - either via the microphone provided or using a line input using the same socket. When taking a ‘sample’ first indicate how many memory ‘units’ you wish to allocate to the sound. The unit appears to be 1/144 of a second and you evaluate units required purely in terms of length of the sound.
Then you go ‘wee’ or ‘boing’ or ‘woof’ or ‘meow, or make any one of those thousands of noises beloved of hi-tech rock bands (anyone who says ‘nineteen’ gets their wrist slapped). And then you hit the first real snag with the Cheetah system, Once the sample is complete, you can’t just play back the sound it has to be configured first. This involves determining exactly where the sound is to begin, where it sustains, where the sustain ends and where the sound ends. Confused? So was I.

What it means is that in the period of time you have sampled (in which you said ‘woof’) you might also have breathed heavily to begin with and coughed at the end. Using the system you edit those bits out by fixing markers on to a graph of the sound which snows precisely where the sample is to begin and exactly where it ends. The sustain is simply a section of sound which is ‘held onto’ until it is time to end the sound like ner. ner, ner, ner... (you know what).

This is all very clever and the graph of the sample (which can extend over many screens - you scroll through it) is quite interesting, but there ought to be a way of avoiding this stage if all you want is a ‘straight’ sample just to try out the system. There isn’t.
Having got your ‘woof’ or whatever, you can save it, reverse it (fffoooooooowww) and mix it with another sound (my attempts always sound like radio interference, however).

It is a lot of probably completely pointless fun and with care the samples can be made surprisingly effective - perhaps even marginally better than those attainable using the Music Machine.
I suspect, however, that for some people the utilities program may be the Cheetah units strongest selling point. This is a separate program loaded independently from the sampler software which produces ‘live’ transformations of input. Put another way, as you speak into the mike it’ll do all sorts of silly things to your voice.

Transformations include Reverbe, Echo, Fuzz Box (it makes everything screech as though Saxon are in concert). Sound Chopper cuts the sound up as though being switched quickly on and off and the Bubblizer just makes very, very odd noises.
There is an option to save ,the software and all files to Microdrive and to use banks of memory for extra samples in the 128K.
The system seemed to work with no problems and the manual supplied contains basic details of operation (although occasionally leaves you with a suck-it-and-see - this is a function to be used rather than explained).

The Cheetah Sound Sampler is a Lot of fun, I don’t really think it stands an earthly as a serious musicians tool now that the Music Machine is around (to be brutal about it).

But it may still be worth investigating if you just want to play around.