BUYING A VINTAGE SYNTH

Buying A Vintage Synth

Published in SOS September 1994
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If you're on the lookout for a vintage synth, it pays to know what to check before buying -- have you ever tried to find a replacement for a 25-year old fader? GORDON REID takes you through a complete synth checklist.

Like a desirable classic car, buying a vintage keyboard can be a big step. Some synths, such as a MemoryMoog or ARP2600, can be expensive investments -- especially if they prove to be unreliable. The following article, which applies equally to mono and polysynths, analogue and digital, aims to help you spend your money wisely and safely, guiding you through a minefield of faulty keys, intermittent cables and dry joints. And remember, if the first vintage synth you find is a bit of a dog, don't be in too much of a hurry to hand over your hard-earned, and don't give up. Contrary to myth, unless you're hunting for a Yamaha GX1, there's a lot of good serviceable gear out there.

Many prospective purchasers plunge straight in, twiddling knobs, pressing keys, playing lead lines... But the first place to start should always be an inspection, starting with the case. You can learn a lot by inspecting, for example, the screw heads on the underside or rear of the synth. How? Because they are almost always painted, and even a single loving caress from the serviceman's screwdriver will be visible. Therefore you should immediately be able to see whether your potential investment is genuinely in the 'out of the box' condition the advert promised. A further indication of misuse (or at least heavy use) will be mismatched or even missing screws. As soon as you come across either of these conditions it's time to start haggling hard. Of course, there's nothing to stop the seller from inserting a whole new set of matched screws to fool you, but if he's willing to do that, the chances are that he's taken care to look after the synth in other ways as well.

What about the case itself? Let's state the obvious: if the case is battered, the electronics are going to have had a rough ride. Yet it's amazing how few people remember in the heat of the moment that it's much harder to put a 3-inch gouge in a wooden side panel than it is to smash a keyboard contact. Many vintage synths have wooden end cheeks, so check these first. The rear panels will also give you many clues to abuse, and plastic cases will show clearly any signs of wear and tear. But perhaps the best indication you'll get will come from the underside of the synth. Gigged keyboards develop scrapes and scratches from sitting on top of other keyboards and, in particular, metal stands. The oft-used line "never gigged" comes crashing down in many cases if you simply turn the synth upside down or, if the instrument in question is a 100Kg CS80, if you get down on your hands and knees for a close inspection. Mind you, a gigged synth is not necessarily an unreliable one, but it's had a harder life than one that spent 10 years on top of grandad's Wersi organ, so you'll know to approach the mechanical checks more cautiously. A final hint here: wooden synthesizers can be repainted. The undersides are usually black, and the end cheeks are varnished or stained, so check for the tell-tale signs of scratches or gouges underneath the paintwork. These will often look like small grooves because the paint tends to soften the profile of the damage. And if the end cheeks are wooden, see if they have been re-stained to hide the horrendous damage caused when the synth was dropped on its side by the previous owner's roadies. If you want to be really cautious, it's often worth having a good knowledge of the original colour of the wood, because a serious con-man might take the trouble to re-stain the whole synth to prevent inconsistencies.

It's much more difficult to disguise damage to vinyl-cased keyboards (such as electric pianos, the ARP2600, and many early Rolands) than it is to wooden ones, so a quick inspection will tell you what you need to know. Wear and tear, as opposed to abuse, is easily recognisable as such, and you should use your judgement in deciding whether to remain interested in buying or not.

The next thing to examine will be the keyboard itself, and there's one simple check that will tell you most of what you want to know in 10 seconds. Guitarists use this trick on their instruments' necks, and would never think of buying an axe without first running this simple check, but for some reason keyboard players tend to overlook it. Place the synth on a flat, stable surface, and crouch down so that you can sight along the keys. (The flat surface is important, because larger polysynths can flex if they're badly supported.) Are the keys all in a dead straight line, or do some stand proud or, worse still, sag down towards the case? If the keyboard is 100% linear, breathe a big sigh of relief -- it's probably in excellent condition or, at least, if having required maintenance in the past, it was serviced by someone who really knew what he was doing. A non-linear keyboard is a sign of perhaps:

1. Serious wear on the pivots, indicating a lot of heavy use over the years.

2. Amateurish maintenance.

3. Existing uncorrected damage.

The following checks (which you should carry out even if the keyboard looks perfect) may tell you which of these applies.

• First, check that none of the keys are badly chipped, broken, glued back together, or have cigarette burns. Whilst none of these necessarily indicate a useless keyboard, they certainly tell you whether it's been looked after. Chips, breaks, and glue tell you that, at some time in the past, the keyboard took a bad knock. This may have bent or cracked the key pivots, distorted the keyboard support frame, damaged the buss-bars, distorted return springs, bent opto-sensors... the list of possible problems is extensive and potentially expensive. My advice: if the keyboard shows clear signs of physical abuse, walk away.

• Have you been practising your chromatic scales recently? No? Well do so. One of the things your little old piano teacher never told you was that a chromatic scale (ie. every semi-tone on the keyboard) played very fast and hard can stop you from blowing £1000 on a naff synthesiser.

• Select or set up a very percussive sound with no extended release envelope. This will stop mis-triggering notes from blurring into each other. Next, if you're testing a polysynth, put it into 'unison' mode if it's got one, select low key priority if you're playing up the keyboard, high key priority if you're playing down and then amaze the seller with your blindingly fast virtuosity. Don't worry if the synth sounds funny or mis-scaled; your only intention at this stage is to test the action of the keys themselves. The chromatic scale will test the keyboard in many ways, although it can be far more revealing on monosynths than it is on polys. Nevertheless, any dodgy contacts will show up, because your scale will sound uneven if keys mis-trigger, and any electrical faults in the keyboard scanning circuitry will be encouraged to reveal themselves. And finally, sticky keys will leap out at you, because the next two or three notes won't be able to sound until the stuck one releases (this explains why you must select the shortest release time possible).

• If the synth passes the first chromatic scale test, play the scale again, but more gently. Then very gently. Then very hard. Play it again. And again. If the guy selling the thing isn't in a hurry to con you, he's not going to mind. Keep playing, and don't be embarrassed. Listen to the keyboard, and feel the response: are the notes 'speaking' exactly when you expect, or do some notes feel a little odd? Do they all require the same travel to initiate the sound, or are some more demanding than others? If the keyboard is velocity sensitive, do all the notes respond equally, or are some deafeningly loud whilst others require the force of a small steam-hammer to coax a response from them? And is the velocity response linear for all the keys? The keyboard may also be pressure sensitive, in which case you must test the force required to initiate the pressure-sensitive effect. This must also be equal for all keys, otherwise your sax solo is going to be dull and lifeless on some keys, and warble ridiculously on others.

Only if you're happy with all of these tests should you permit yourself to play a few lines from your own repertoire. It's well known that keyboard players' critical faculties are totally nullified by playing their own music, and you should be convinced that the keyboard plays perfectly before you test its response to your own favourite licks.

What should you do if you find faults or intermittent keys? Judgement is going to play a big part here. I can almost guarantee that the seller will leap to the synth's defence with, "oh, it's just some dust on the key contacts". Of course, it may be true, but there's a simple test for it. Choose a dodgy note and play it hard a few times. Is it still causing problems? Hit the key a hundred times if necessary. If it remains unrepentantly dead it's... dead. If it shows signs of life, or has returned to normal functioning, it may well be suffering from lack of use. Only you can decide whether to take the risk where a naff keyboard is concerned, but in my experience, a keyboard fault is the most expensive fault you're going to come across. If in doubt, walk away. There are other synths about -- you don't have to risk a dodgy one.

One other area of concern is keyboard scaling -- check that if you play a C in the bottom octave, you also get a C when you play one in the top octave. In addition, many monosynths (such as the ARP Odyssey) have octave selection switches, increasing the range of, say, a three-octave synth to seven octaves or more. These can also be mis-calibrated, and should be checked carefully. Scaling faults tend not to be fatal, but they can be expensive to remedy. After all, the minimum charge at a service centre is likely to be £40 or more, so you should definitely ask for a price reduction if the scaling is anything less than perfect.

Depending upon the instrument's age and nature, its control panel may consist of almost any combination of rotary knobs, linear faders, multi-position switches, momentary switches, rocker switches, membrane switches, passive buttons, backlit buttons, cursor keys, joysticks, and even alpha-dials. Each will exhibit specific tell-tale signs of developing problems, and all should be checked.

Many vintage synths -- Moogs and Sequentials, for example -- have rotary knobs which control the synth's voice creation parameters, and nearly all synths have knobs controlling basic functions such as master volume. As above, before using your hands, check with your eyes. Are all the knobs the same? It's amazing how many synths have had bits and pieces lost over the years, and how many owners have just shoved on any old knob which would do the job. Check also whether the knobs show signs of damage. A very common give-away is scuffing of the knobs' heads. This indicates that something significant has been dropped onto the synth, dragged across the top of it or, in the very worst scenario, the synth itself has slid upside down along a concrete floor. If your prospective purchase shows signs of serious scuffing, guess what... it's time to walk away again. This is because rotary potentiometers (which are the devices that lie behind the visible knobs) are delicate, and not designed to take any weight. The accuracy and continuity of their response is highly dependent on very fine contact tolerances within the component; even if it survives, it may well be board mounted (ie. no support is given by the case of the synthesizer) and serious damage could be done to the circuitry within the synth.

The final visual test is a little tricky. You should inspect to see whether any contact fluids have been used on the knob. These fluids are often used by the unscrupulous to disguise the (in)action of dodgy potentiometers. The worst fluid of all is WD40 which, whilst a godsend on BMWs, is a disaster for synthesizers, offering short-term functionality at the cost of long-term destruction. You want the axle behind the knob-head to be completely free of such fluids, most of which can be detected by an oily, sometimes black residue which often attracts dust and fluff. Ask the seller whether you can remove a knob-head to have a look. If he refuses, check as best you can.

If the knobs pass the visual test, it's time to check their function. A good knowledge of the synth is vital here: it's no good determining that a knob has a smooth progressive action if the sound isn't changing in the way it should. The best course of action is to set up a very basic patch (use the manufacturer's manual if it's available) and test the response, from minimum to maximum, of every knob in turn. Ensure that you perform these tests by adjusting the knob slowly, thus testing for continuity at all positions, and then quickly, which will make any crackles more apparent.

It's the same for faders: eyes first, hands second -- but be even more thorough in your inspection. Linear faders have rubber sleeves designed to keep the worst of the world at bay -- except that they don't. A vintage synth may be anything up to 25 years old, and it has had ample time to collect balls of dust and fluff the size of the Isle of Wight. These often accumulate inside the faders. The WD40 factor applies here too -- perhaps more so than above, because there was a myth in the '70s that it helped preserve contacts as well as making them more reliable. Aaargh! Be very, very careful. Unlike rotary potentiometers (knobs), many faders are now out of production, and you may be unable to replace any scratchy, crackly, intermittent ones except by cannibalising another instrument. Did you really intend to buy two identical synths?

The first time you move a fader, check very carefully that it is not stuck in its current position. If untouched for months or years, the movable contacts will often bind themselves to the contact track inside the body of the fader and, if forced too suddenly, can tear away some of the contract strip. Not nice. If you suspect that this has happened, free the stuck fader very very gently, and then test its action at all points along its travel. A little care will often ensure that no damage occurs, but you may not be the first potential purchaser to inspect the instrument. Who knows what damage the previous potential buyer did?

Buttons and switches tend to be easier to check, and to replace if necessary. Although there are so many different types (multi-position switches, momentary switches, rocker switches, membrane switches, passive buttons, and backlit buttons) they tend to work, or not. The exception to this is when a switch or button becomes intermittent. This may not be a fatal flaw -- for example, when the action of the switch is eventually stored in the memory of a programmable synthesiser -- but it could be a disaster if the control starts to jump between states in the middle of a performance. Check also that any LEDs associated with the control are both lit and extinguished correctly. Faulty operation now could be an indication of problems to come.

Membrane switches require particular care. Check that the paintwork on and around them is not too worn. A good rule of thumb is this: if the legend on top of the switch is illegible it has probably been abused. Membrane switches are, contrary to myth, very robust, so if they appear very scruffy, or act intermittently, don't allow the seller to blame the manufacturer.

Finally, check the appearance and action of any cursor keys, joysticks, or alpha-dials. Performance controls such as these should always be smooth and continuous in action. Being more modern types of control, these tend to be more easily replaced or repaired if necessary, but why take risks?

If you're not a seasoned synth buyer, it's good advice not to venture into the secondhand synth market alone. It's a jungle out there and, in the absence of intimate knowledge of the area, you should always take a native guide with you. Most musicians or prospective musicians know somebody who will be delighted to show off how much they know about synths, so don't be embarrassed to ask -- it could save you hundreds of pounds.

SOUND CHECK

OK, so the case looks fine, the keyboard is linear, the knobs and switches all work, and there's no sign of physical abuse or evidence of past cover-ups. Everything is perfect, isn't it? Sorry -- no. You still haven't tested the sound generation of the synth. Well, that's not strictly true, because you've played the keyboard and you know that it makes a sound, but is it the correct one?

If the synth has memories (and un-editable factory presets are particularly useful here) you can check that the sounds relate to the names of the patches. If they do, it's a fair bet that all the sound generation components are working correctly. In the case of memory-less monosynths, things are a bit trickier, and you'll have to check each parameter individually. Again, a knowledge of the synth is very important, although a general understanding of analogue synthesis will probably see you through.

Obvious things to check include:
• Oscillator waveforms -- are they what they claim?
• Do the pulse width modulators work?
• Do all oscillators track evenly?
• Does the filter open and close correctly?
• Does the filter track the keyboard linearly in self-oscillation?
• Do the envelopes range from near instantaneous to very slow, as they should?
• Can you route the modulators to all their claimed destinations?

If the answers to all these questions are 'yes', then you should ask a few negative ones. For example: do the envelope controls affect, say, the oscillators or filter in ways that they shouldn't? It's not unusual for electrical faults such as dry joints, short circuits, or collapsing components to manifest themselves in this way, and they can be a bugger to track down.