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Casio FZ20M | |
Digital SamplerArticle from Music Technology, March 1990 |
With two-minutes of sample time, Casio's FZ20M would seem to be an instant contender for any serious sampler's shortlist - but size isn't always everything, as Vic Lennard discovers.
When Casio's FZ1 appeared it was the cheapest 16-bit sampler on the market. Nearly three years on we're looking at the modular FZ20M; how does it fare?
THE FZ20M IS a 16-bit sampler with two megabytes of RAM, which can record at three different sampling frequencies - 36kHz, 18kHz and 9kHz. The audio bandwidths are approximately 16kHz. 8kHz and 4kHz respectively, which means that the highest rate is likely to find quite a lot of use, while the lowest is unlikely to see much use at all - but it's reassuring to know it's there. The 36kHz rate gives 29.12 seconds of sampling time while the lower rates will give double and quadruple this figure.
Subject to the size of the samples, up to 64 'voices' can be stored in memory. Eight programs, called Banks, can each have up to 64 Areas assigned to them, an Area being a voice and its associated parameters. There are two main modes: Play, and Modify, where Voices and Banks can be edited in various ways.
THE FRONT PANEL is roughly divided into three parts. The centre has the visual display (6 x 4cm approx.) with the screen menu selector buttons directly beneath it. To the left are the keys for moving around the screen and from page to page, while the right-hand side has the numeric keypad, input and headphone sockets and value/sampling level sliders.
The rear panel has eight monophonic audio output jacks along with a 'mix' output in the form of balanced XLR and unbalanced jack. This has a low/high output level selector switch while the individual outputs are all effectively low-level. This shows up clearly when operating the machine and tends to cancel out the low output noise by demanding high gain levels be set on the mixing desk. A single footswitch, balanced mic input, the three mandatory MIDI sockets and two 25-pin ports complete the rear panel. The External port allows direct connection of the FZ20M to another member of the FZ family, while the HD port is intended for an Apple SCSI (small computer serial interface) hard drive.
WHAT ELSE IS a sampler for but making samples? Source Select on the main menu gives you four options; sample a voice (Sampling), mix together two existing voices (Mix and X-Mix Write) or convert a voice to run backwards (Reverse Write). Choosing the first option takes you to the next page level. From here, by going through the menu options one at a time, a voice is defined (named) and set to a note on the keyboard. Record level can either be High or Low (though I can't see the latter getting much use), while the trigger sets the input level for auto recording. Finally you must set the sampling time and rate. At the bottom of the screen is a horizontal meter which registers the incoming signal in two ways - average, by a continuous bar, and peak by a single mark. The Sampling Level slider gives you control over the incoming level. Now you must either use auto sample to start the recording procedure as soon as you play something or manual sample which starts the recording when the Yes key is pressed.
Your first playback is likely to show up the fact that experience is needed with the FZ series to get good results, as it's likely to be either distorted through too high a level, or drowned in background noise through too low a level. There's no way of monitoring the sound while you are taking the sample and the internal pre-amps are not very forgiving.
HAVING TAKEN A successful sample, various editing features are available;
Truncate - this allows you to delete part of the sample from the start or the end. There may have been a click before the signal which triggered the recording, or the end of the sample may be noisy. The only problem here is that the manual gives no indication as to what the numbers for start and end actually mean. Guesswork time.
DCF Envelope - the change of filter with respect to time is handled by this eight-point envelope. Independent level and rate for each point along with the option of a sustain plateau are on offer. Cutoff frequency and resonance tailor the overall tone.
DCA Envelope - this is another eight-point envelope which permits you to accurately shape the dynamics of a voice. The features per point are the same as for the DCF, whose envelope can be copied into the DCA.
"The highest (36kHz) sampling rate gives 29.12 seconds of sampling time, while the lower rates will give double and quadruple this figure."
Loop Set - a loop is the replaying of a portion of a sample to create the aural illusion of a continuous sound. The FZ senes is unique in that each voice can have up to eight loops with crossfading from the end back to the start of each loop for a glitch-free sound. This latter procedure is not the same as crossfade looping which actually changes the waveform and is offered as a feature in the optional software (see later).
What makes all the above far easier to work with is the graphic display. You can actually see the waveform that you're working with and even though the screen is small, the resolution is high enough to give you a clear idea of what's happening during an edit.
Other features include LFO Set which can modulate the DCA for tremolo and DCF for active filtering, and Velocity Sensitivity for setting how the DCF, DCA and resonance respond to key velocity.
THERE ARE MANY reasons for requiring a variety of sounds across a keyboard - the most obvious one is to accurately recreate a natural instrument like a violin. Let's say that the first sample is taken at C3. This can be played back up and down the keyboard but will suffer from what's known as munchkinisation at the top end and sound funereal lower down. There's usually only a small usable range of notes which can be used for playing back each sample. Perhaps the next sample will be taken at G3. Then the first sample could have a top key group note of D#3 while the second sample would then start at E3. This would continue until as much of the keyboard is covered as required. The groups might overlap, although that is less likely with a natural instrument. Another example could be the setting up of a drum kit across the keyboard. Each of these setups constitutes a Bank.
Using Bank Edit, a bank can be named and all necessary voices can be mapped into Areas. Each area can have a high and low note along with maximum and minimum velocity, overall level, MIDI channel and output socket assign. Individual banks and voices can then be saved to disk.
MOST OF THE MIDI facilities are what you would expect to see on a synth/sampler but there are one or two surprises. Modulation wheel (MIDI controller #1) and Channel Aftertouch can be directed to the LFO oscillator for vibrato effects, to the LFO or the DCA for tremolo effects, or to the DCF to control the cutoff frequency (and hence the timbre). There is also mention of a variable resistance foot control (Foot VR) which I assume means that you can plug a Yamaha-style sustain pedal into the rear footswitch socket. This type of pedal changes the resistance across the pedal output as the pedal's position is changed. The manual mentions practically nothing about this. Apparently the FZ1 has an extra socket on the rear panel for an optional pedal, the VR1, but this doesn't exist on the FZ20M. In which case, why leave the function?
The level of the DCA and DCF can also be changed using the above three methods. The first will vary the volume while the second varies the cutoff frequency. All in all, more than you would expect from a sampler.
The other MIDI facility which is covered is that of data dumping over MIDI to a computer librarian or from the external port to another FZ. This opens up interesting possibilities. Steinberg's Avalon and Interval Music Systems's Genwave (on the Atari ST) will both extract samples from the FZ and transfer them to other samplers and vice versa. This could be most useful as the Casio library is certainly not the best in existence. Instead, you could download samples from an Akai S1000, for instance. The computer software would have to convert the sampling frequency as not many samplers work at the frequencies offered on the FZ20M, but this feature is covered in both the above-named pieces of software. It should be mentioned that the sample dump that Casio use is not the standard MMA version and that there is a booklet of some 100 plus pages which delves into this area. Tsk tsk, Casio.
CASIO PROVIDE A disk as standard which allows you to load in five extra features as and when you need to use them. It would be better to have all features within the machine, but there it is.
The first extra feature is the Hard Drive Operator (spelt "Operater" on the FZ's screen). This provides all standard hard drive functions as well as allowing you to transfer the optional software, so removing the need for the extra floppy disk.
"The eight-point DCA and DCF envelopes allow you to shape the sound into any form you wish -taking sampling a significant step further."
Next up is the Wave Synth, which is used for creating sounds from scratch. The first method is to use a preset waveform selected from square, sawtooth, pulse, double sine, saw-pulse and random for creating analogue synth sounds. This can then be edited within the edit voice menu. Alternatively, up to 48 sine waves of varying amplitudes can be added together to build an original sound. This form of additive synthesis should, in theory, allow you to create practically any waveform you might want. A lot of experience is needed to create a sound "to order" however, although it's always possible to stumble across interesting results. Having put the sine waves together, you then "execute" the procedure, which creates the sample. The next page lets you truncate the result. "Hand drawing" can be used to either change the newly-created sample or to draw one from scratch. The only problem here is that using cursor keys and the value slider are not conducive to an accurate result. Still, it is a useful tool for editing samples.
The other functions, Loop and Fade Optimiser, pick up where the standard looping facilities leave off, using crossfade looping techniques which alter the original sample. The only problem is that loading either of these functions erases anything currently in memory. Now, when you save voices in a bank, you can't access them individually. For instance, let's say that you have a bank called Brass and one of the samples needs the use of the Loop Optimiser. Loading up this optional function erases all samples from memory, so you then have to load the voice that you wish to edit. You then have to save the particular Brass sample as a Voice and reload it. This problem exists throughout the saving facilities of the FZ series. You can save the internal memory as a whole, or as individual banks, voices and effects but cannot load any component of a saved file - only the entire file.
SUBJECTIVELY, THE FZ20M sounds good. Samples have low background noise even though the actual sampling procedure isn't the easiest to work with.
I sampled sounds from DAT onto the FZ20M, an Akai S950 and an Akai S1000 - although the sampling rates had to be different. The S1000 only samples at 44.1kHz and 22.05kHz so the higher rate was used, while the S950 has a variable sampling rate up to 48kHz. Two samples were taken on this sampler at 36kHz and 48kHz.
Unsurprisingly, the S1000 gave a more accurate representation of the tone, due, in part, to the higher sampling frequency. The timbre of the instruments sampled were far clearer and the background noise was negligible. The FZ20M simply did not have the top end response which is not surprising given the sampling rate. I suppose the result would have been closer had I used sounds from a standard cassette, but DAT is a very clean medium.
In terms of facilities, the FZ20M is difficult to beat. When the FZ1 first appeared, the multiple loops were looked upon as being gimmicky and of little use, but with over 29 seconds of sampling time, they really come into their own. Similarly, the eight-point DCA and DCF envelopes allow you to shape the sound into any form you wish. This takes sampling a significant step further. Vibrato is usually added via the LFO and most samplers simply give you a sine wave which is too regular to be convincing. The choice from six options means that this is not the case here.
There are certain areas in which the FZ20M is lacking, however. Looping is the most important technique in sampling, and the FZ's facilities leave much to be desired. The other frustrating aspect of its operation is that you spend half of your time motoring through pages on the FZ screen. Here Casio could learn from the example set by Akai and Roland with their samplers. Roland make it possible to use a computer monitor and mouse for expediency, while Akai have the most user-friendly screens currently known to (this) man.
The FZ20M's biggest drawback is its eight-note polyphony and eight monophonic audio outputs. This arrangement is fine for drums, but it makes a mockery of the memory size - which is big enough to hold a bank of strings and brass, but the only way to play them back is through the "mix" output.
While I'm griping, it would be useful to have an indication of how full the memory is, and also whether there is any room left on a disk. Talking of disks, the FZ20M will only accept High Density (HD) ones, which are far more expensive than the usual Double Density variety although they do hold twice as much data. I also found it very off-putting to find the disk drive continuously spinning even when not in use. I don't know whether this is standard or if there was a problem with the review machine but it seems to me that this shouldn't be happening.
THE FZ20M IS an enigma. On the one hand it has a large memory and programming functions usually restricted to a synth; the graphic screen means that most of you will get by without having to spend hundreds of pounds on a piece of computer editing software. But this has to be measured against the monophonic outputs, less-than-friendly operating system and the fact that the sound quality is good but not brilliant.
There is far more competition now than in mid-'87 when the FZ1 appeared including offerings from Roland, Ensoniq and Cheetah (all of which are cheaper than the FZ20M). Perhaps the real problem is that the FZ10M retailed at £1299 meaning that the hard disk interface is costing £400 - the machines are otherwise identical. Even more farcical is the fact that most shops are selling off the end of the FZ10M series for around £799. The FZ20M's price is going to have to drop significantly if Casio intend to continue to compete in the market.
Price £1699 including VAT.
(Contact Details)
Casio FZ1 - Sampling Keyboard
(MT Jun 87)
Casio FZ1 sampler
(MM Jun 87)
Browse category: Sampler > Casio
Review by Vic Lennard
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