Yamaha CS80

Hi all.

Hope it's cooler where you live than here (southern California)!

I have a mystery for everyone. I just had a CS80 dropped off today
for a couple of (I hope) simple repairs. It's SN 13-somethings and in
pretty good shape and tuning. However, someone had previously
installed some kind of unison mod to it. The current owner was told
that it used to (many years ago) belong to Frank Zappa (Jobson era???).

I've opened it up a bit and taken a few pictures. They're in the
Photos section of the Yahoo group in album "Unison Mod." Does anyone
recognize this and/or know who did it? It seems to work.

When the lower switch is set to "U", the keyboard is in a dynamic
unison mode. Hitting one key stacks all 8 voices (sounds amazing!)
while hitting more keys starts splitting the voices. Hitting
additional keys doesn't send new triggers to the EGs, so it's like a
legato mode.

When the switch is set to "S" is seems to be in some kind of single
mode, in which new keys are assigned to upper or lower voice cards.
The upper switch somehow affects this assignment, but I haven't
figured out the algorithm yet.

I haven't lifted the keyboard yet, but I'll post pictures of the
mystery circuit board soon.

One thousand Quatloos to whomever can tell me about this thing.

David

p.s. CS80s are not fun to carry around in 95° heat!

>One thousand Quatloos to whomever can tell me about this thing.

To find out how it works, it would be good to see where these wires from the
switches are going. :)

Somewhere on the Key assigner board?

Or just re-wiring the Gate signals (as a previous owner has done in my
CS-60) ?

JH.

--- In yamahacs80@yahoogroups.com, "JH." <jhaible@...> wrote:

>
> >One thousand Quatloos to whomever can tell me about this thing.
>
> To find out how it works, it would be good to see where these wires
> from the switches are going. :)

Done - just added three pics in the folder.

> Somewhere on the Key assigner board?

Big time! I'm glad this is all working, since I don't want to go near
it! Lots of CMOS (with no bypass caps!!!) tied into the KAS, TKC, and
who-knows what else.

So, anyone recognize this?

David

>> Somewhere on the Key assigner board?
>
>Big time! I'm glad this is all working, since I don't want to go near
>it! Lots of CMOS (with no bypass caps!!!) tied into the KAS, TKC, and
>who-knows what else.
>
>So, anyone recognize this?

Certainly different from what I've found in my CS-60.
Just out of curiosity: Are the extra CMOS ICs mostly *switches* (like, 4016,
4066, 4051, 4052, 4053), or have they re-built some of the logic?

JH. (Wish I had a CS-80. Anybody has one for sale ?? :) )


Yahoo! Groups Links

Hey David,

Any chance you might be able to post an audio file of what the unison sounds like? I
would love to hear it.

And yes-it's way to hot here in Southern CA!!! My circuits are melting!


Thanks,

Stephen Teller

--- In yamahacs80@yahoogroups.com, "David Rogoff" <david@...> wrote:
>
> Hi all.
>
> Hope it's cooler where you live than here (southern California)!
>
> I have a mystery for everyone. I just had a CS80 dropped off today
> for a couple of (I hope) simple repairs. It's SN 13-somethings and in
> pretty good shape and tuning. However, someone had previously
> installed some kind of unison mod to it. The current owner was told
> that it used to (many years ago) belong to Frank Zappa (Jobson era???).
>
> I've opened it up a bit and taken a few pictures. They're in the
> Photos section of the Yahoo group in album "Unison Mod." Does anyone
> recognize this and/or know who did it? It seems to work.
>
> When the lower switch is set to "U", the keyboard is in a dynamic
> unison mode. Hitting one key stacks all 8 voices (sounds amazing!)
> while hitting more keys starts splitting the voices. Hitting
> additional keys doesn't send new triggers to the EGs, so it's like a
> legato mode.
>
> When the switch is set to "S" is seems to be in some kind of single
> mode, in which new keys are assigned to upper or lower voice cards.
> The upper switch somehow affects this assignment, but I haven't
> figured out the algorithm yet.
>
> I haven't lifted the keyboard yet, but I'll post pictures of the
> mystery circuit board soon.
>
> One thousand Quatloos to whomever can tell me about this thing.
>
> David
>
> p.s. CS80s are not fun to carry around in 95° heat!
>

Maybe Kent can provide us with some information about his mods. Kent,
didn't you have an unison-mod prepared? Any progress on midi (in/out)?

The mod on the pictures seems like a lot of work, but it seems to be
done very professionally ! This mod asks for a unison detune-slider ;-)

Kent is restoring my Cs80 at the moment, he is also doing a unison mode on
mine as well as fitting a boss dimension d chorus and boss ph-3 phaser
(instead of the onboard chorus and tremolo) and adding kenton midi..
I cant wait to get it, hopefully at the end of this month! :)

> Maybe Kent can provide us with some information about his mods. Kent,
> didn't you have an unison-mod prepared? Any progress on midi (in/out)?
>
> The mod on the pictures seems like a lot of work, but it seems to be
> done very professionally ! This mod asks for a unison detune-slider ;-)
>
>
>
>
>

JH. wrote:

> Certainly different from what I've found in my CS-60.
> Just out of curiosity: Are the extra CMOS ICs mostly *switches* (like, 4016,
> 4066, 4051, 4052, 4053), or have they re-built some of the logic?
>

I just put a couple of better pics in the folder so you can see the
chips. It's not just switches: I see a bunch of 4013 flip-flops on the
main board.

David

mine as well as fitting a boss dimension d chorus and boss ph-3 phaser>

Why not pull out the voice cards, and put something else in it while you kill your CS80. I draw the line at Midi. Unison would be cool, but using a Dimension D chorus? Is this the Roland one?

Why not just hook up the Dimension D to the CS80's outputs?

Ok, I finally put up an audio file of the CS80. Look in the Files
section of the group for cs80_unison_mod.mp3. It's a bad recording
(CS80 -> computer speakers -> Olympus voice recorder) and I was just
making stuff up, but it's there. The file alternates between normal and
unison mode. The unison mode is louder since all 8 voices are playing,
but it's not much thicker. It really needs a detune knob! Toward the
end of the file I detuned the upper and lower, which does sound thicker
in unison mode. One obvious thing is that the envelopes/triggering
works differently in unison mode. It's kind of a legato setting as you
can hear in some parts of the file.

David

phaseshifter11 wrote:

> Hey David,
>
> Any chance you might be able to post an audio file of what the unison sounds like? I
> would love to hear it.
>
> And yes-it's way to hot here in Southern CA!!! My circuits are melting!
>
>
> Thanks,
>
> Stephen Teller
>
> --- In yamahacs80@yahoogroups.com, "David Rogoff" <david@...> wrote:
>
>> Hi all.
>>
>> Hope it's cooler where you live than here (southern California)!
>>
>> I have a mystery for everyone. I just had a CS80 dropped off today
>> for a couple of (I hope) simple repairs. It's SN 13-somethings and in
>> pretty good shape and tuning. However, someone had previously
>> installed some kind of unison mod to it. The current owner was told
>> that it used to (many years ago) belong to Frank Zappa (Jobson era???).
>>
>> I've opened it up a bit and taken a few pictures. They're in the
>> Photos section of the Yahoo group in album "Unison Mod." Does anyone
>> recognize this and/or know who did it? It seems to work.
>>
>> When the lower switch is set to "U", the keyboard is in a dynamic
>> unison mode. Hitting one key stacks all 8 voices (sounds amazing!)
>> while hitting more keys starts splitting the voices. Hitting
>> additional keys doesn't send new triggers to the EGs, so it's like a
>> legato mode.
>>
>> When the switch is set to "S" is seems to be in some kind of single
>> mode, in which new keys are assigned to upper or lower voice cards.
>> The upper switch somehow affects this assignment, but I haven't
>> figured out the algorithm yet.
>>
>> I haven't lifted the keyboard yet, but I'll post pictures of the
>> mystery circuit board soon.
>>
>> One thousand Quatloos to whomever can tell me about this thing.
>>
>>