Saving the Yamaha CS-80 (5) TSB Control Boards

[backindauk]

Hey Gavin,

Thanks for posting this. I am restoring a CS80 at the moment, with two more waiting.It is a time consuming but very worthwhile process.

I'm just wondering which desoldering tool you are using? I've been using a "gun type" Weller one but it just died and i am back using wick - the gun is heavy on my wrists also. I think going for something with the suction unit away from the handpiece would do me well.

Andrew

[gavincurtis]

@backindauk Sorry that I have taken so long to respond. The tool that I am using is a vacuum desoldering system. Specifically a Weller WR-3M, but many low cost versions that work just as well are available.  Definitely get a vacuum desoldering tool because as you know the CS-80 is insanely complex.

[backindauk]

@gavincurtis

Thanks for the reply Gavin. I ended up ordering a Hakko desolder station which should be here this week - i think it will be 100x better than the desolder gun i had before. I also bought a CS60 and a Rhodes Chroma which both need full restoration. I might well be crazy :|

[gavincurtis]

@backindauk Hakko was exactly what I was thinking of but couldn't remember the name! From the company I purchase my Weller stations.

[skyprop]

I've seen less cable bundles in photos of the Space Shuttle wiring!!!!! :)

Damn!!! A technicians party going on there for sure!!!

[gavincurtis]

@skyprop Somebody cared about what they were building.  Need more of that today. :)

[noddyspuncture]

Just love your vids Gavin. Keep 'em coming please..!

[gavincurtis]

@noddyspuncture

Thanks! Should have the next one up by the middle of next week.

[Synthfool]

Glad you're doing this video series.

I've been doing the same- restoring a CS80.

This one here is getting all new caps and all new trimmers. Likely some CMOS chips also.

Already done with the power supply and several boards, but LOTS more to do.

Trims are a big problem on this one, btw.

But I'm using much better kinds and hope it will stay in tune better. The CS80 is built like a home organ. :(

Good luck! :)

[gavincurtis]

@Synthfool

Good idea on the trimmers. The originals are nasty.

Going to try the sealed 12 turn cermet type.

Unlike the originals, they are designed to stay where you put them regardless of bumps or vibrations.

[Synthfool]

I'm using Bourns 25 turn cermets.

I've never seen 12 turn ones, but sure they'd be better than the stock ones by far.

I agree- they're horrible.

[gavincurtis]

@Synthfool

I used 12 turn mini cermets (6mm square) on the KAS and board as the standard 10mm didn't fit properly. But the rest of the boards the 10mm 25 turn fit nicely as they are conventional and ideal.

Anxious to hear how much less noise the VCA's will play without the easily 500+ evil OEM carbon (and oxidized metal) pots ruining the sound!

Replacing the original BBDs with the modern low noise versions would probably help much when using those circuits too.

[gavincurtis]

@Synthfool

You are right, 25 turn... my mistake. I bought smaller units to fit on the SH board and were 12 turn. But the normal are the 25 turn.

Any suggestions about resistors on the LSI D/A converters? The KAS board uses .01% for the D/A voltage ladder, but the KBC boards use 1% which control the voice cards. I was thinking of upgrading to .01% wirewound.

Any ideas? Going to try .01%.

[Synthfool]

Are they really .01%?

I would think .1% or matched 1% would do.

I tend to use CMF55's handmatched in various synths.

Sometimes Vishay/Holcos.

I don't the rest of the synth is .01% accurate though.

You know... we should really take this to email. ;-)

[thrcman]

wow, very nice work. admire your technical skills, nicely done and thanks for posting!

[cnightwing]

Great work , thank you for taking the time to make these videos.