Saving the Yamaha CS-80 (6) SH Sample and Hold Module

[luciangabriel95]

Hi.I want more vids...do you have more?

You are great

[gavincurtis]

@luciangabriel95 Someday soon! Keyboard pressure transducers video soon.

[gavincurtis]

Stability should be a working synth. I am replacing rotted capacitors in the power supply and in all digital timing and pulse generator circuits which need to be stable (as intended). The etheric magic of this machine is from the 16 independent oscillators that will NOT be modified.  But temperature and transport stability will be improved. My CS80 will not become a digital brick as some seem to think.

[hartleytransform]

@gavincurtis Hi Gavin, I've a CS60 which is working pretty well except for one problem. It's stuck on Sustain II mode even when the switch is moved to sustain I. (ie, the note stealing is permanently on). Apart from the switch itself which I think is fine, could you suggest what else can be checked to see why it's stuck in Sustain II mode?

[backindauk]

@hartleytransform

Hey there,

I'm working on a CS60 at the moment and it intermittently has the same problem. I'll debug and if you send me a message i will reply with the detail.

[fourbarposer]

Uhmm... Have these mods (dif type of caps and even values) been approved by golden ears synthesist to not change the "soul" of the instrument? More stability could translate into "more static and boring". If it was any other synth I wouldn't care as much to come and comment on your repairs but this really is special synth and who knows what exactly makes it special - since the people making synths since haven't been able to get the qualities of this one into theirs!

[gavincurtis]

@fourbarposer And just in case, all removed parts are organized/saved in order to put everything back to before. 

[ezquimal]

when can see a video with you playing this instruments?

[gavincurtis]

@ezquimal Next video where I rebuild the KAS board I get the lower 2 octaves working and I play.

Editing that video but editing computer failed. Video will be here soon.

[gavincurtis]

@ezquimal video of me playing is now on youtube.

[aidabab]

Hi great video, whats that de soldering tool your using called, Ive never come across one of them before

[gavincurtis]

@aidabab

It's called a vacuum desoldering tool.

[aidabab]

@gavincurtis thanks for the info :-) great tool

[jonathan401]

@gavincurtis ..otherwise known as a 'solder sucker'

[gavincurtis]

@cumesoftware They fit quite well actually. In the video the new pot pins look much farther apart, but the body of the pots fit flush against the board. No modifications to the board.

[gavincurtis]

@cumesoftware

Hi, Thanks for posting. The parts are extremely high quality. But manufacturing processes and materials of today surpass that of nearly 40 years ago... making more precise and reliable components.

Worst part of the CS-80 are the single turn carbon trimmers. If Yamaha used multiturn pots, nobody could afford this keyboard.

Digital tuning is also very difficult as this is an extremely complex analog synthesizer. Been working on microprocessor digital tuning retrofit. but damn.

[RudyZombe]

Nice videos!. You are doing a good job!.

[Cubik303]

Another great video! I really look forward to each one and they are very educational for me. Keep them coming!

[twidknobbler]

Amazing and fascinating stuff. These videos are invaluable, especially for budding synth techs like myself and others. Is your CS-80 currently playable? It would be nice to see functionally how it performs and how any problems and issues manifest when you play it. I have repaired a few old analogue synths but nothing as beautiful as the legendary CS-80. My next project will be to replace all the capacitors in my Korg PS-3100 - do you have any tips or advice? Keep up the great videos!

[gavincurtis]

Thanks.

It partially works (whenever it wanted to), which is why it is being restored. In the KAS video, you will get to hear it.

[gavincurtis]

because it blew fuses and couldn't be played until one final IC on the KAS board was replaced.