OT: synthesizer care

[aron]

Hey guys,

Here's a question for you. I have a number of synthesizers - one in particular - that was made in 1994/95. Obviously it's getting on in age. It's not an analog synth and I would hate to lose it. In your opinion, is there anything I can do to maximize the chances for it continuing to work? I mean, is it even worth trying to change caps now? Should I keep it running most/all the time?

I know a number of people that have non-working keyboards (myself included) because we left the units off and in storage. What would you consider a reasonable thing to do? Turn it on every day for a little while?

I never worried about this before, but this is a rare keyboard and it was $5k initially.

[Rodgre]

Very good question. I think that if you use it at least once every few months, you really shouldn't have to worry about the electrolytics. I have lots of gear from the 80's that I've had no failures with, so it's not a given that just because it's 20+ years old, it has to fail.

With that said, I think that general cleaning and proper care go a long way and if you're even asking about this, you probably take better care than a lot of people.

I have worked on a Casio PG-380 midi guitar which is notorious for the surface mount caps failing. They were falling off the board in some instances. Replaced them with small non-smd caps. If your synths have been reliable this long, odds are that you're not going to have caps flaking off the board. Do a check, though. A once-every-year or two internal check for infrequently used gear is a good practice. Open it up, clean internal connections/ribbon connectors, clean the pots and switches and replace memory batteries once every 10-15 years. Keep the keyboard contacts clean. This is always voodoo to me. I fear that cleaning or examining key contacts will do more damage than good, depending on the keyboard. Don't get me started on the nightmare I'm dealing with on an old 60's combo organ whose key triggering setup is very complex and not easily repairable.

Fast cycling between hot and cold and hot and cold is bad for solder joints and pc boards. While I've been very lucky to not have many problems like this in the studio I run, which is in a barn: very cold in the winter, very hot in the summer, I have fixed enough cracked solder joints and pc boards from temperature changes as well as dropping to know how easily it happens. Hairline cracks will drive you nuts, giving unpredictable issues.

I will end by saying that we all know that these things weren't made to last forever, and a lot of our electronic gear (unlike, say a printing press or a weaving loom from the 1800s) is destined to fail someday. Aron has the right idea in at least being aware of it and trying to eek out as long a life for this equipment as we can, until they no longer have use to us because our fingernails will eventually have pico-circuitry built into them, with the equivalent of a thousand Korg M1s and Moog Little Phattys.

Roger

[amptramp]

There are usually a lot of switches and pots in a synthesizer that need cleaning.  Even storing them in a house where someone smokes is enough to turn ON-OFF-ON toggle switches into OFF-OFF-OFF switches.  Board connectors are of variable quality, but for most commercial equipment, the quality is pretty bad, so clean those too.  The keyboards usually need some work.  An expensive synth usually has loudness of each note determined by pressure or velocity sensing.  Velocity sensing uses two switches per key and determines the time between switch closures that is translated into loudness of the note - faster means louder.  These can be tricky to clean, but it should be done.  I would look at getting a lot of contact cleaner into the various switches and pots before I started playing with other limited-life items like electrolytics.  Also, if IC's are socketed, pry them up and push them back in without removing them - this breaks most layers of corrosion and airborne contaminants.

If you leave it on, play it, so that the keyboard switch contacts will clean themselves (although contact cleaner should still be used), and operate any other selector switches throughout their full range.  Otherwise, leaving it on will just increase the failure rate.  Back when I was doing military and spacecraft design, we used to consider the failure rate of a unit that was off as no more than a tenth of the failure rate when it was on.  You may want to add MOV's or transient suppressors for the power input - this really helps absorb abuse.

Caps that are 16 or 17 years old are not likely to show problems yet, but figure out the sizes you need for the day you have to put in an order - they are definitely going to be needed in a few years.  It helps to use high-temperature devices with a higher voltage rating than the originals.

[amptramp]

There are usually a lot of switches and pots in a synthesizer that need cleaning.  Even storing them in a house where someone smokes is enough to turn ON-OFF-ON toggle switches into OFF-OFF-OFF switches.  Board connectors are of variable quality, but for most commercial equipment, the quality is pretty bad, so clean those too.  The keyboards usually need some work.  An expensive synth usually has loudness of each note determined by pressure or velocity sensing.  Velocity sensing uses two switches per key and determines the time between switch closures that is translated into loudness of the note - faster means louder.  These can be tricky to clean, but it should be done.  I would look at getting a lot of contact cleaner into the various switches and pots before I started playing with other limited-life items like electrolytics.  Also, if IC's are socketed, pry them up and push them back in without removing them - this breaks most layers of corrosion and airborne contaminants.

If you leave it on, play it using every note, so that the keyboard switch contacts will clean themselves (although contact cleaner should still be used), and operate any other selector switches throughout their full range.  Otherwise, leaving it on will just increase the failure rate.  Back when I was doing military and spacecraft design, we used to consider the failure rate of a unit that was off as no more than a tenth of the failure rate when it was on.  You may want to add MOV's or transient suppressors for the power input - this really helps absorb abuse.

Caps that are 16 or 17 years old are not likely to show problems yet, but figure out the sizes you need for the day you have to put in an order - they are definitely going to be needed in a few years.  It helps to use high-temperature devices with a higher voltage rating than the originals.