CS-60 modifications

[Rory McDonald]

Juergen:
My CS60 is also modified, by Marvin Jones, no less!
I dont know if this is a similar mod, but it is definitely a pro job.
It is pretty fortunate for me that it has the mods it does,
considering I am a PAiA nut and want to interface the CS60 to my
old 8700 system. Mine needs tuning/calibration as well.
I have the docs from Yamaha to do that (just no time til after my mentorship
program is over).
Here is what he says he did to it:

Hi Rory, 

Well, I never thought I'd see this one again.  You must have bought that
CS-60 from Bill Boydstun in Southern Cal, right?  Or else you got it from
someone who previously got it from him.  

The mod to that machine was done in the summer of 1980, just before both
Bill and myself moved to the west coast.  He went to the LA area, and
started working with the guys from Synapse magazine.  And I went to the Bay
area to take over Waves engineering up here.  I did a LOT of mods for him
over the years.  

Anyway, the touch switch on the front panel switches between using the
internal keyboard to control the voices, or using the external LINEAR
control voltage inputs to control the voices.  Bill was using a Paia QuASH
system to output computer sequences from an 8700 system, and wanted to
playback using the better (and more manageable) voices in the CS-60.  (Can't
blame him!  ;-)  )  

That's all the details I recall about the job just off the top of my head.
The whole mod just interrupts signals going from their keyboard outputs to
the voice cards.  So it would be very easy to remove the mod, restore the
original connections, and have a pretty much stock CS again.  (minus the few
open holes in the case.  ;-)  )  

Hope that helps the mystery some.  Good luck with it.  

mj

-----Original Message-----
From: Haible Juergen [mailto:Juergen.Haible at nbgm.siemens.de]
Sent: Monday, December 11, 2000 4:49 AM
To: analogue; DIY
Subject: CS-60 modifications


I got a new toy - finally I have a CS-60.
(and no intention to get a CS-80 anymore.)

It's in quite good condition, needs some tuning, and some
cleaning of contacts.

And ... it's modified.

The seller was a little secretive about the previous owner
(he said he sold it for a former band mate, and I don't know
his name), but I'd be interested to find out who did the
modifications.

There are two long shafted toggle switches below the rotary
sliders for touch sensitivity, and apparently these are switching
the CS-60 in a dual VCO mode, sort of.
But apparently it's not just an ordinary Dual mode (with 4 voices),
but something more sophisticated. First inspection showed that
a group of Gates (or CVs ?) is switched, and first listening test
hints that it still has more than 4 voices sounding in that 2VCO 
mode. Maybe just some doubling of the last note which is depressed ?

I'm curious to figure it out, and I imagine I can figure it out the hard
way,
but I'd rather get in contact with the person who modified it.

Now there might be a chance that the tech who did this is on the list.
There aren't that many people who modify CS-synths, after all.

It's actually some piece of *good* work that was done here (unlike
many other mods I've seen), with cables routed in bundles where they are
not in the way for service.
So if you read this and it reminds you of some work of yours, don't be 
shy and contact me (;->)

JH.


PS.: Anybody familiar with cleaning CS-60 key contacts in particular ?