[sdiy] Arp Odyssey sliders cleaning/ restoration

[Dave Manley]

Thanks for getting that out of the archives.  The tech I referred to in 
my post was Kevin.  One item to note: he informed me a while back that 
he no longer uses the 'Luberex' product, stating that it was 
reformulated at some point (perhaps due to ROHS, he wasn't sure) and he 
doesn't like the new product.

A key point to note is that he doesn't take apart the sliders unless the 
shaft is broken - cleaning is done with the sliders on the board.  When 
taking apart the Odyssey vintage CTS sliders it is very easy to break 
the metal clips that hold the plastic pieces together.  Digging in the 
archives will show people have a number of solutions for that.  I'll 
have to take my calipers and measure and old part vs those from 
SynthRestore - if the clips are the same, maybe they would be willing to 
sell some clips.

-Dave

jeff brown wrote:
> 
> This was covered several years ago on this list by Kevin Lightner. 
> Rather than being a weenie and telling you to search the archive for it, 
> I'll insert it here ;^P
> 
> ---------------------------- Quote from May 24, 2004 (I think) 
> -------------------------------
> 
> Hi Bob,
> 
> Hope this doesn't come off sounding too self-absorbed, but it's not
> easy to note what *I* do without using the *I* word often.... ;-)
> 
> 
> 
> I do wash boards, though I've a few precautions and practices well down.
> For me, I use high pressure softened water and usually a good grease
> cutting detergent.
> I prefer SimpleGreen for this as it's biodegradeable and easily available.
> Also De-SolvIt is great, but is oily and it itself must be removed
> with simplegreen as well.
> I don't allow things to soak too long, but 3-5 minutes immersion is
> usually needed to dislodge old grease.
> After a rinse, the boards are blown using compressed air and placed
> in a forced air dryer.
> A hair dryer (not too hot) will substitute fine. Allow them to sit
> overnight before powering up.
> 
> Boards are often washed when originally made and soldering, both by
> hand or machine, exposes a board to higher temperatures than any
> water you'll handle, even boiling. The main thing is that water is
> not left to dry and leave mineral deposits or react with metals to
> oxidize (rust, aluminum oxide, lead oxide, etc). The only components
> that have ever acted up, and rarely at that, are the larger foil
> wound caps found in CV memory circuits such as key memory and sample
> and holds. I replace them if so, but out of about 30-50 Odys that
> have received this treatment, only 2 needed components replaced.
> Those odds are well within my confidence range considering the
> positive results otherwise.
> 
> One plus about this technique is that it removes coatings on the pcb
> that can degrade audio and CV's.
> It's quite common to have things more stable and of better fidelity
> after a total cleaning.
> Sample and hold circuits can droop simply from body oils on a board.
> Imagine what 28 years of atmospheric junk can do when accumulated.
> 
> After washing, most sliders feel much better, but keep in mind that
> immediately afterwards they are still wet inside and will still feel
> lubricated. After drying, they will need new lube. I use GC
> Electronics Luberex and apply it through a hypodermic syringe. It
> helps to remove and disasemble one slider so as to give you an idea
> what points require lube the most. Lube on the resistive element
> generally won't hurt it or affect its operation, so you don't have to
> be ultra careful. I will also use a drop or two of TriFlow Teflon
> lube if they need to be a bit less frictional. It's all on a "as
> needed" basis, so I'm hesitant to provide any blanket rules or offer
> this as the bible of slider repairs. This is what has worked for me
> and is proven over time.
> 
> The sliders are not terribly easy to remove nor to replace the shafts.
> You must remove the entire slider in order to swap the shafts also.
> I really don't know how to detail what's involved if you've never
> done the operation before.
> Like teaching guitar via email: I could take apart 20 sliders in the
> time it took to write this email, but it took years of doing and with
> many failures that taught valuable lessons. I would recommend some
> smooth jawed flat pliers and whatever you feel comfortable with for
> desoldering. If I didn't use power desolderers, my next choice would
> be solderwick. The little bulb or piston solder suckers just don't
> cut it for me. More pain than they're worth.
> 
> When I use or offer sliders for sale, they are made up of selected
> parts from several sliders.
> Often the tops are hand polished to get them smooth again and remove
> scratches.
> The inside wiper plate and contacts are polished using swabs and chrome
> polish.
> They're solvent cleaned and relubed, then assembled, checked for
> proper tension and then bench tested using an audio generator and
> scope. Lots of work for sure. The payoff for me (besides the money)
> is getting an Arp to feel almost brand new. Many people have no idea
> how nice they can usually turn out.
> They've never played a new one.
> 
> Also, I very much recommend on any gear, a very close inspection
> under bright light.
> Solder connections, especially on larger pins and connections, or
> leads of items that are subject to physical force are the most common
> places. Pins that carry high current or experience higher
> temperatures are subject to premature cracking as well.
> I do this operation to *every* board of *every* unit that comes in
> here. No exceptions.
> It's that important. The pcb is the most important component and
> makes the most connections.
> So many repairs I and other techs do everyday is nothing more than
> resoldering cracked pcb connections.
> On some units, I won't even power them up until this is done. For
> example, the display board of the Roland S-50 is sooo often filled
> with cracked connections, it's assumed that's needed everytime. After
> a while, one gets savvy where to look and what to touch up. My secret
> weapon to not seeing any rework ;-)
> 
> Hope this helps!
>