When Nice Beverages Go Bad!

When people think about equipment getting drinks in them, the first thoughts are of wild parties and raucous gigs and if a synth is going to be destroyed, at least it went out in style, like the end of a 60’s Who gig.
Alas the truth is far more banal, about 90% of all liquid damaged (or ruined) equipment that comes through here has met its end courtesy of the humble tea or coffee. Perhaps this is not so surprising, as musicians working in their studios think nothing of parking a cuppa next to their pride and joy while they fine tune their greatest work. Despite the greatest of care and attention, accidents will happen, a curl in an instrument cable being repatched, a careless elbow, the possibilities are endless. How do we fight this scourge on Synthkind, and still enjoy a brew?

Obviously having no liquids near your gear is one option, but a little draconian given the many hours spent with our music gear, but how do we have a brew and yet keep the gear safe?

In the workshop we enjoy a cup of tea as much as anybody, and after several hours spent searching for a dead gate on a chip in the CPU of a synth, we will have drunk many cuppa’s during the search, and have a celebratory other one when the culprit is found! The answer, be sensible and organised, find a space in your work environment where if the worst happens, no damage to electronic gear will result, and always put your beverages there, you won’t have to think about it, just reach out and touch your coffee. In over 20 years of repairing synths, and countless thousands of cuppa’s there has not been a single accident of that type, (electric shocks and solder burns, deep flesh wounds and splinters yes, but no liquids in a synth or piece of test gear).

The effects of liquids in music technology equipment has increased in the last two decades due to the small size of modern devices (especially those 200 pin IC’s that are in everything now), and one drop of any liquid is enough to short out at least 3 pins, and surface mount devices tend to suck any liquids under them by capillary action, which may short out a lot more than that and take a considerable time to dry out even if the gear is not used. If it is, then electrical damage is possibly being done, slowly eating away at the tiny pins of these IC’s until the pins break and the circuit board won’t take solder any more, and these IC’s impossible to obtain.

Not just tea and coffee by the way, Atlanta’s finest. and any of the sugary soft drinks will be equally if not more destructive, as will any spirit and a mixer.

If you have to have a liquid of any sort near your Tech Gear, organise a routine where you know exactly where it is without thinking about it, put it always in the exact same place, and maybe we won’t ever have to tell you “sorry it’s gone”.

There were a great many liquid infested synths here in the last couple of months, most were fixable, a couple were not, and this is why we made this a blog subject.

The Oberheim Deluge

After many years of not seeing many of Tom Oberheim’s products at all barring the odd Matrix 6 or 6R (the rack mounted version) we have been inundated in the last few months with some of Tom’s finest, a couple of dead Xpanders, a couple of unwell Matrix 6R’s and an OBXa, and the Matrix 12 is also still with us. Joining every relevent forum has not been very productive, but perhaps no surprise there. They are all well built and engineered but also all have weird problems that defy most of the more common and logical diagnosis techniques, and on forums there are no shortage of those solutions that one person or other swears is the Holy Grail of advice and this is how they made their Obie perfect once more. We have read them all and none of them are in any way relevent to any of the issues here right now. The great “Recap everything” thread will always be there and some people may have got lucky with that one, but it is not going to help with anything we have here.

Last week we bought a Tektronix TDS420 Digital Oscilloscope to aid in some of the more arcane problems that even Analogue hybrid polysynths can be prone to, hopefully between it and its analogue scope counterpart we will be able to see what the problems actually are, although even with the best of equipment you have to measure the right question, and obviously figure out which measurement question to ask, and this is part of the legendary diagnosis time that Tech’s worldwide charge for. All the Obie’s here have weird and obscure problems that will take a lot of time to figure out, already a lot of expensive spare parts have been purchased, just to have them in house if a suspicion is raised about any particular IC, and possibly we have the best collection of those parts in Europe. One of the Xpanders had been to some well known Tech’s in England, and it had been both pillaged for valuable IC’s and also butchered by what I hope was an apprentice, (if not, God help you all in the UK), we bought every spare to restore this if the damage hasn’t been too great, and while we are not massively confident about this particular synth, we are as good to go as is possible.

Keeping Old Korgs Going

Some of Korg’s offerings from the early 80’s are becoming more desirable as time rolls by, such synth’s as the Trident, the Polysix, the MonoPoly and the Poly 61. All of these are interesting and good sounding machines but they share a common failing after 30 years, the Panasonic keyboards used in them. The rubber contact strips for these have become pretty well unobtainable (and have been for several years now, although the Poly 800 shares the same type of keyboard and there are lots of dead Poly 800’s due to battery damage).

Last week we got two Polysixes which we had already seen in the last year, one got a CHD MIDI interface fitted only 8 months ago and at the time the keyboard was surprisingly perfect for an EBay purchase, but it wasn’t last week, 14 keys across the keyboard didn’t work at all. The other Polysix had lot of dead keys about a year ago, but a complete strip and rebuild of the keyboard fixed that at the time, but that didn’t last. It seems that these old Panasonic keyboards require constant playing to keep them working, we had a Poly 61 over the weekend whose keyboard was completely stripped and rebuilt 6 months ago, but after getting the synth working the keyboard still had about 20 keys that didn’t work, but that number reduced to 2 after the keyboard was exercised for a while. Yet if you dismantle the keyboard completely and “play” the rubber pads alone on their PCB, a freshly cleaned keyboard will be perfect until you put the keys back in, so what is going on here?

Over the last year we have been fitting thin plastic shims on the bottoms of the rectangular key actuators on any Panasonic keyboard that has been completely stripped and cleaned, but still had the odd key intermittent, repeated dismantling and rebuilding of the keyboard doesn’t seem to improve things very much, in fact every time you dismantle and reassemble the keyboard pcb, a different random bunch of keys won’t work any more, and they require a lot of repeated playing to bed them in again.

The shims are simply pieces of 1mm thick modelling Polystyrene used by modellers and architects and available from most good model shops worldwide, and Superglue (Isocyanoacrylate or Crazy Glue as I believe it is called in the States) is the ideal bonding agent, just cut a rough sized piece of Styrene, glue it on and then trim the resulting assembly with side cutters. It seems to cure those rogue keys which defy all cleaning.

The reason for all the preamble is that we put shims on every key on both Polysixes from last week, it was very time consuming but all the keys worked fine after this, only time will tell if this is a permanent solution to this problem, and we hope it is, as the Matrix 12 here has the same make of keyboard, as does an OBXa which got a shim on a black key which didn’t respond to anything else.

There is a kind of logic in this solution to the problem, the part of the key that presses the rubber button is rectangular while the button itself is circular, something about square pegs in round holes comes to mind.

One of our two Polysix owners reported back that the feel of the keyboard had also been improved, apart from actually working, he felt the response to be better also, time will tell.