CZ-1000

Casio used phase distortion synthesis in their range of synthesizers, PD is a bit like FM without the frequency.

The sounds available have a unique character and the user interface is good apart from some parts of editing, such as the envelope editor which suffers from having a multi-stage envelope with just a small LCD and no shortcut keys. The membrane keypad is an obvious weak spot, if mine ever breaks I think I'd find a way of repairing it even if it required lots of glue and individual clicky switches.

M-10

I bought this from someone who was also selling an MT-400v, which I should've bought too.

I expected this little preset synth/organ to be rubbish but it's far from rubbish

It sounds a lot like the MT-40 but it's smaller, is satisfyingly heavy for its size and has a smoother sound from a more limited selection.

One of the reasons I like it is its simple design and layout, it also has the most killer lousy yet amazing electric piano sound. Stick it through a delay and it sounds electrifying, in a sort of post-electronic way.

MT-40

Like the M-10 but with more sounds, funky rhythm box and a familiar sounding bassline generator added on.

I've owned this since I was about 11 years old.

The digital whine that accompanies its output is wonderful and I should put a sample online so people can use it standalone.

MT-45

Like an MT-46 but instead of the nasty silver-brown colour it's cream which suits it.

MT-46

Like an MT-40 but with full sized keys on the bassline section, different sounds and more variety, such as a selection of arpeggios.

I picked this up at a car boot sale, the power switch had been lost to corrosion caused by battery leakage.

Because this machine wasn't in great condition I've just hardwired the power switch to ON rather than seeking out a replacement, but this works for me.

MT-65

Great sounds, great accompaniment section. Creamy goodness. This is a real winner. Too bad they went on to make a dismally coloured version, the MT-68.

MT-68

Like the MT-65 but using the grim grey-brown plastic colours first used in the MT-41. On my MT-68 one of the keys feels a bit loose but there are no other problems. Casiotones were really built to last.

PT-1

Brainless version of the VL-1, these should not exist but do.

I believe they can be circuit bent to be slightly more interesting. I don't believe in a lot of circuit bending, it seems like a lot of it is bandwagon-jumping and isn't offering something that's viable as an artistic performance device. I think art should be more directly related to the person who makes the choices, so DIY circuit bending on things is great but buying pre-bent uncontrollable things and then claiming that their random wibbling is art or music is just copying others without acknowledging the art in what they did when they first coaxed the wrong sounds out of various boxes.

PT-50

My Ebay sourced PT-50 is a little worse for wear but I wouldn't be without its crazy rhythm/backing patterns, although maybe I would if I had a PT-30 which has the brilliant Fantasy sound.

PT-80

It has a slightly different set of sounds to the PT-50.

PT-83

Like a PT-80 but dull.

SK-1

Yes, it sounds good but it seems to have the strangest UI I've ever seen on a Casio. It's as though they rushed the design. Prefer the SK-5.

SK-5

The greatest comedy synth ever. Don't miss an opportunity to get one if you don't already own one.

VL-1

My first synth, if you can call it that, which you can.

VL-5

Ebay again, my VL-5 looks nearly new and even has the mad and space age barcode reader wand which works just as badly as it did when the thing was released in the early 80s.

Quite a bad sounding machine, this one.

K3m

I've had this for years and it has been scarily reliable. I reckon this is the best-built synth I own.

I seem to be some kind of Korg Fan.

The MS-20 was my first proper synth, before that I'd had casio keyboards starting with the VL-1, then MT-40 and MT-400v.

Mono/Poly

My favourite synth. It's has a great layout and because of the 4 VCOs it has amazing depth in spite of sounding quite thin. It is hard to explain, really. I can see why some people don't like the Mono/Poly as it tends to only sound great when it is doing sounds that only it can do but for that reason alone I think it's valuable.

This is something I've had to do three times in the 15 or so years that I've owned my Mono/Poly. Most recently I tried a new tactic and it seems to have paid off so I thought I'd share it.

You see, I've read suggestions of using denatured alcohol, pencil erasers, even brass polish. It turns out that Bounty kitchen tissue is perfect without any additives at all. It's abrasive enough to remove any nasties from the gold contacts without removing any noticeable amounts of gold. It's also perfect on the conductive rubber pads on the underside of the bobbly key membrane.

I was concerned that it might be impregnated with something that would destroy the key contacts, but I did my most recent revival over six months ago now and all the keys work perfectly - in fact they work better now than they ever have.

Having waxed nearly lyrical about Bounty I'm sure other similar products would work, Bounty is good because it holds together and doesn't shed lint.

MS-20

My first MS-20 and first proper synth came from an antique furniture seller at the Ascot Car boot sale in the late 1980s when it was seen as a bit of an antique.

This was stolen by someone who borrowed it and didn't return it some time in about 1994

As a result of losing the MS-20 I started seeking out alternatives, discovering that many of my now grown-up school friends had amazing vintage synths stashed in lofts or cupboards, these were the synths that their parents had bought them but they'd never used and they wanted to get rid of as they were moving out. It seems incredible to me now, but I managed to spend a few hundred pounds and get hold of a Sequential Circuits Pro-one and the Korg Mono/Poly.

Years later Ebay sellers kept tempting me with MS-20s and I bought a replacement for about 50 times more than I paid for the first one (seriously!)

Keyboard contacts... todo

Poly-61

Bought from a prominent local electronic scrap dealer for not much money. I've managed to get it mostly working but I think it has Poly Six style PCB brain damage.

If it sounded nicer I'd probably restore it fully.

Poly Six

Battery leakage from the original Nickel Cadmium battery is a massive problem on the Poly Six. The chemicals from these batteries not only destroy the metals that comprise the PCB tracks, component leads and solder but they also permeate the PCB and cause phantom connections to appear.

The leaked chemicals don't give up easily, either, so thorough cleaning and replacement of all the PCB tracks and components in the vicinity of the leaked battery is crucial for a long term repair.

The other weak point is the Matsushita keyboard, a similar unit to the one on the Mono/Poly and Poly-61. This has the same contact problems as those keyboards. The contact problem is made worse if the keyboard has been in an enviroment where it has been exposed to smoke, which seems to get absorbed into the plastics that make up the conductive pads.

Having previously established that PolySix KLM367 boards that have had serious battery leakage can exhibit strangely conductive properties, even after being brushed and cleaned with alcohol I decided to investigate why one of my PolySixes had some serious pitch warble after repair.

It turns out that the track that runs directly under the battery is a high-Z mixer input enroute from the front panel bend/tune knobs to IC8 where it's summed with MG signals via the 4066. Unfortunately, even when this track looks reasonably OK and tests <0.5 ohms you may find it's less than 1Mohm to adjacent digital signal tracks. I think Korg had thought this would be a problem - if you look under pcb at the CN06 end of the track there's a big solder pad that appears to be intended for a hookup, perhaps a for a screened cable?

So, I lifted one end of R9 (10k, near IC8) and substituted a monolithic 100nF instead of C43 and pulled CN06-2 out of its shell, connecting to the junction of R9 and my monolithic ceramic cap.

No more warble, in fact it's purer than I had expected.

The fix is not permanent yet, I have to figure out a way of making it a bit more elegant. I'll probably use a bit of hot glue... maybe not so elegant.

Wavestation A/D

The LCD backlight is one of the weak points of the Wavestation and in the Wavestation that I bought on Ebay it had been replaced inexpertly. The replacement process had done irreversible damage to the glass of the LCD which was still functional but missing several lines of pixels.

I decided to replace the entire LCD with a modern white LED backlit unit as these are now very affordable and can be obtained with similar dimensions to the original Optrex DMF-5005 display.

I found a display manufactured by Zhongli on Ebay from an overseas seller, this turned out to be absolutely perfect and has much better contrast than the original as well as being incredibly bright.

It's worth noting that LED backlit 64x240 pixel graphic displays are sometimes considerably deeper than the original, this wasn't the case with the Zhongli unit. I've found a web page detailing how to replace a Wavestation (keyboard) display with a deeper LED backlit one - it wasn't pretty - the process involves cutting swathes of the original PCB out and replacing it with hand-wired connections.

The process for fitting the Zhongli display was simpler, just a few resistors to adjust the contrast voltage that is sourced from the front panel contrast knob and a dummy-load resistor for the old EL-backlight inverter to stop it screaming.

Matrix 6R

Seems to be mostly reliable at the moment.

TR-505

Someone had thrown this away, but I got to it before it was landfilled. The snare drum button doesn't work.

TR-606

I've got two 606s, they're great things. The second one is missing a few knobs and was bought as scrap. It was non-working due to shoddy Roland build quality, something that affects the 606 and 303. A few dabs with a soldering iron where there had never been solder before fixed it. I may even get new knobs for it if Ebay keeps tempting me.

TR-707

I bought this from Phil from Running Frog. I used it for some years as a MIDI/Din-sync bridge, something it does wonderfully.

U110

One of the first mass-market ROM playback machines and sister to the D110 LA synth.

I've had one problem with this, I still don't know for sure what caused it. The U110 would start up and crash shortly afterwards with random sounds and display contents. It seems to have been a loose internal connection that was triggered by the unit heating up. Reseating the ICs seems to have fixed it but I'm not sure that the problem won't reappear as it may have been a dry solder joint that I disturbed during the reseating process and has yet to settle back into its failure mode.

MC-202

A classy instrument, as the gentleman in Slough's ABC Music put it when I bought it. Two channels of CV-Gate, one of which drives the onboard SH-101 style synth.

The rubber power cables on the Pro One seem to perish around the cable clamp grommet thing. I was tempted to replace the cable with a modern PVC mains cable but then I realised that the rest of the cable was undamaged and showed no signs of failure.

The fix was relatively fiddly, the clamp had to be released by poking with a screwdriver and squeezing with some long nosed pliers at the same time. The cable could then be fed into the synth, stripped back and resoldered onto the terminals and the clame refixed.

The other thing that will be a problem by now is the keyboard. It has small rubber parts that sit under the keys, these act as buffers and provide a small amount of steering to the key to keep it central when it's depressed.

Unfortunately, like the cable, the rubber doesn't last forever and on both my Pro Ones there has been some crumbling. It's possible to buy kits of parts to restore the whole keyboard properly and I shall probably do this eventually. For now I've managed to stretch some thick rubber cable sleeving over the metal fingers in place of the crumbled parts and although I don't get the benefit of the steering effect I still have a satisfactory key feel and roughly level keyboard.

Pulse+

todo

PS-3

I fell in love with the Portasound in Eastbourne. There was a music shop not far from the Winter Gardens where 11 year-olds could annoy their parents and passers-by using state-of-the-art Yamaha technology thanks to a rack of most of the range standing in the shop doorway.

My favourite was the larger PS-20(I think) which I nearly bought at a recent car boot sale as it had a better speaker, full sized keys and better automatic chords etc.

Yamaha stuff was always quite expensive, so I got a Casio VL-1 instead

When I see PS-3s I buy them, so far I've got 3 but only one is fully working.

None were completely dead and two came with the excellent hard case.

The sounds are quite bland on the PS-3 but the vibraphone is excellent and the PS-3 sits really well in a mix with other more complex syths without too much tweaking, it's strangely sophisticated inside too.

From my examination it would seem to contain a VCF chip similar to the one used in the Yamaha CS01 as well as a few other common elements.

DX-7 mk1

Volume slider failure, I have hardwired it to "max"

TX802

This is similar to a rackmount DX7-II, really excellent machine. The only work this required was a lithium battery replacement. The new one is in a socket so it should be an easy job to replace it in future.

CS 5

The most playable monosynth ever, at least for me.