MIDIFICATION OF YAMAHA CS5

[matoz]

Hi all,

A good friend of me have found a YAMAHA CS 5 in a bin (mega lucky man!!), and we would like to midificate it.

It will be the first time i midificate an instrument, and don' t know at all how doing it.

I saw in the forum lot of midification but these are all spécific.

Is someone know how should i do?

thanks

best regards

[Futureman]

I've got a CS5.. Not a bad synth, cool filter.

it's an analogue synth, so a midi-cv converter is all you need to control it via MIDI.. (just one that does Hertz/Volt & S-Trig)

Obviously the parameters would not be controlled via MIDI. To do this would be would cost a fortune.

Regards

Mike

[matoz]

Thanks,

so, i just need only 1 core and 1 Aout LC and MBCV appli?

if i have understood well, i just need 1 CV out?

[matoz]

Futureman: the transfo is missing, could you tell me what kind of transfo is it?

I saw it should be a parallel (symetric)psu but what voltage is it?

[Futureman]

Do you mean the power transformer inside it is missing?

Do you have the schematics / Service manual?

As there is no digital inside the CS-5, I'm pretty sure the power transformer would be a simple 15-0-15 Transformer (Just a guess for now) but see if you can get the schems before I take my CS-5 apart to check for you ;]

Regards

Mike

[matoz]

Yes, the power transformer is missing.

I' ve found the user' s manual but it i didn' t find any schematics.

Regards

Loic

[Futureman]

Yea, Yamaha are very good for user manuals..

Search for the CS-10's service manual / schematics.. they are very similar.

And if you are too lazy for that..

http://www.emusic-diy.org/YamahaManuals#head-02ff64e6bb572d98e47c2c680831c76ab8de3f67

At a glance... +-15Vdc & +10Vdc is used..

Regards

Mike

[matoz]

thanks, i ever saw cs-10 schematics but i think it is a little different.

the PSU is different according countrys.

in CS-10 there is -15/0/+15 and +10, so 4 wires.

Here, there must be only 3 wires.

i' m afraid to grill something if i try -15/0/+15 or -15/+10/-15 ...

i have sent a mail to Yamaha, i' m waiting for the answer to be sure.

or if you want it would be cool if you test it.

regards

Loic

[Futureman]

or if you want it would be cool if you test it.

sheeesh... I don't really like taking apart perfectly working mint gear for no reason... but for you I will.. just send me some Black Truffles or Some good french red wine as payment.. ;]

-> Goes off to dissassemble Yamaha CS-5.......

[Futureman]

This was measured with the transformer disconnected.. ie.. no load.

Regards

Mike

CS5.JPG

CS5.JPG

[stryd_one]

but for you I will..

Generosity. Props.

[matoz]

Yes, many thanks Futureman.

The result is curious but i will try it.

"just send me some Black Truffles or Some good french red wine as payment.. ;]"  :)

Add a beer icon to your profile, or PM me your postal adress..  ;)

Thanks, regards

Loic

[Futureman]

Yes, I was surprised by the 22-0-22.. I'd be pretty sure it would run on something less than that.. even 15-0-15's measure a fair bit higher with no load.. and to be honest, I'd probably try one of those first... you generally can't hurt something by under powering it.. and the CS-5 sure does not seem like it pulls a lot of current. ( ie - it runs very cool)

Why it was without it's power supply in the first place however is the big question? Maybe it blew up? Maybe something is wrong with the synth?

If you get a proper transformer, disconnect the synth from the power PBC (The one in the pic), and check the output from the power PCB (after the regulators etc) before you plug it all together..... those trimmers are probably for the +-15Vdc adjust.

Regards

Mike

[matoz]

Hi, i have the real story of this synth: when my friend have found it, he went at his home to test it, and he didn' t saw that the power is 110V... and he plug it in 220 Volt... the synth made a little sound and... pwwwof, no sound...  He asked another friend of me about the power supply et he took of the transfo. I have it now. All fuses are clean.

I tryed a 15/0/15 transfo, there is no synth sound but i can hear LFO and the LED supply is OK.

I search now a 22/0/22 transfo...

PS: excuse my "frog english"...

Best regards

LOIC

[Futureman]

Did you measure the output from the power supply PCB?

Regards

Mike

[matoz]

yes, with a 24/0/24 transfo, i have +15/+15/0/0/-15/-15 at the output PCB, it seems be good.

The power led is OK, the LFO led is OK with LFO speed. But no sound.

When noise generator is "on" ,whith a lot of volume, i can hear a little the LFO.

regards

Loic

[Futureman]

Damn.. maybe a few things got fried....

Try some simple measurements... is it spitting out CV from it's CV out (If so, does it change with different keypresses etc)? Is the trigger out working (Short to ground trigger)

If not, maybe a whole heap of op-amps got toasted.. I think there is one big custom chip inside the CS5.. I  H O P E that is OK.

I think from here on in, you'll need a oscilliscope to find out whats else is going on...

Goodc luck.

Regards

Mike

[Futureman]

Just out of interest,

I actually got hold of an original CS-5 Service manual.

(I do have a bad habit of collecting manuals & service manuals for stuff I have)

If you are still working on this, and have any specific questions, let me know, I might be able to help you out.

And before anyone asks for me to scan the whole manual, I'll preface by saying it has many fold out inserts etc and one massive fold out block diagram / schematic.

Regards

Mike

[matoz]

Hi Fururman,

That is a good new. If you have shematics and block diagram, i' d like to see it!

thanks

Loic