The Ensoniq Mirage DSK-8 Digital Sampling Keyboard

2 x 64Kb worth of grungy 8bit analog filtered sample mayhem - get the idea?

Let's get this straight first - if you're after a sampler that can play endless streams of high-quality 30second long samples and change the sample list at the touch of a switch, then the Mirage definitely isn't your thing.  In fact, you're pushing it to get a single 6second sample per keyboard half.   But with some careful sample selection and editing, the Mirage can be the best friend of even the most professional samplist.

Samples:  8bit samples, sampling rate variable from 10KHz to 33KHz.

Memory:  2 x 64Kb memory banks, 1 per "keyboard half" (which can be altered to a single key if you really want).  This translates into very restricted sample space if you are talking straight-out samples; but for synth waveform samples, this can be as limiting as a goldfish in an olympic- sized swimming pool...

NB:  64Kb is 65,536samples.  It IS possible to cram a fairly LARGE sample into such a space by doing some creative re-sampling, filtering, etc., it is merely a question of audio quality over sample size.  For example, a 10second sample can be made by sampling at 6.5536KHz - this may sound like a pathetic figure, but it can prove acceptable, depending on what you are after.
Cool Edit is pretty good for this - it can display the amount of samples you have, from which you can take pot shots at resampling until you get the most out of your bank memory!

Keyboard:  5 Octave, velocity sensitive.  Can allocate up to 16 different samples across the keyboard range (8 per keyboard "half")

Filters:  The real unique point of the Mirage, what makes it a true classic.  8 analog filter chips (one for each active voice) give samples a unique sound, "warming them up", giving a bit of life to what would otherwise be pretty crappy 8-bit digital samples.
One of the main beauties of the Mirage's filters is that they essentially turn it into a pseudo-hybrid digital / analog synth - ie., if you've got some sort of basic synth wave-form sample, the Mirage can kinda replicate the synth it came from, or create entirely new synth patches.  Plug a square wave, saw wave, pulse, whatever, into it, and you have a pretty damn versatile semi-analog synth!

• Standard:  Single Sided Double Density 3.5" disk (360Kb) - holds 3 Lower sample banks, 3 Upper sample banks, and 8 sequences.
• Modified: DSDD 3.5" (720Kb) - mod enables use of both disk sides, doubling capacity.

Construction:  The Mirage is to samplers what a tank is to the family car.   Solid steel construction, about 10kg in weight - drop it on a concrete floor and you'll probably do more damage to the floor than the Mirage!
Due to this weight, it's not too good an idea to use a lightweight stand - the last thing you want is the thing collapsing in the middle of the performance.  I went the overkill and custom-made a heavy-duty stand, soon to be modified to take my Roland D5 as well as the Mirage (ie. dual keyboard config)

The Ensoniq Mirage DSK-8 (Australasian model - NB: the disk holder)

Inside the Mirage (filter chips are beside the red capacitors on the right)

Mirage + 1

Really, the Mirage is useful more as a sample player than as an actual sampler - don't get me wrong, it'll sample and do a reasonable job of it, but with the very limited memory you haven't got much to play around with, which means lots of frustrating re-sampling to get it right.  I find the best way of making the most out of the Mirage is to sample on a computer, do all the editing, resampling, filtering, maximising, etc., then dump it all to the Mirage.  This way you can maximise memory usage and sample quality by planning your samples ahead of time and squeezing them into a 64Kb package.

I've uploaded a text file of parameter settings for the Mirage HERE.  It lists all of the variables you may need to set up samples the way you want to hear them, and I've tried to group them together in related areas (eg. filter envelope, master controls, etc...)

Shifty's Page - Samples, hacks, etc
Oscar's Page - Mirage Sample Assigner + more
Tim Victor's Page - .wav to sys-ex converter, OS hacking stuff, + more

Here are some problem's I've had with my Mirage, and how to overcome them

Constant "SU" display
When I first got my Mirage, after booting, it would constantly display "SU", and not register any keypad entries.  After much stuffing around, I unscrewed the hood and checked the keypad buttons and wiring.  The problem lay in a permanently depressed "Sample Upper" button, which I freed, thus solving the problem. While I was at it, I also taped up some wires that looked like they had the possibility of wearing through and shorting out.

Missing notes!
This is a reasonably common problem with the Mirage (I've had 3 blown!!) - you play along merrily, and notice that some of the notes are not sounding.  The first thing to do is to play 8 notes simultaneously - if one note misses, do it again, and again.  If you still only get 7 notes playing, the problem lies in the sound processing centre.  This could be a real pain to track down, but often the problem lies in the Curtis VCF chips (the CEM3328), the heart of the processing stage.

The best way to test this is by finding pin 9 on each chip (audio out), connecting this to the signal line of a listening device of some sort (eg. headphones - oh, and make sure you connect the earth to an audio earth) and having a series of 8 notes play continually - an easy way of doing this is to pre-make a simple multi-note sequence, then play it back in sequence loop mode.  Go around to the audio outputs of each VCF, and if one doesn't give output at all, swap it (after switching the unit off of course) with one you know works, and try again.  If you don't get sound out of the chip by moving it elsewhere, then you have a stuffed chip.

The following site may possibly have the chips available -
CEM List - the chips to look for are the CEM3328

If you do get sound from it, and the chip you moved to it's position doesn't make sound, the problem lies somewhere in the stages between the processor and the VCF - something I can't help with.