/g/yamahaCS80fans

Re: Do we have a list off all the errors in the calibration manual?

Adhmzaiusz@... (Gregory Cox) — Mon, 11 Nov 2024 13:13:30 -0800

Hey Michael and everyone, I am indeed part of the group and thanks for chiming me in :)

As Michael stated, the resonance seems to “collapse�� when you adjust too far, but iirc I noticed if you raise the brilliance paddle up to top then back to centre you can “regain�� the level and continue from where you had it collapse, allowing it to go further up in p-p voltage. Hope that makes sense!

The one observation I noticed doing it this way however is the relationship of this calibration to the brilliance paddle movement. For example once calibrated to a higher p-p voltage, raising the paddle from middle to top then back to middle keeps the maximum resonance centred—however lowering the paddle to bottom and back to middle the balance point becomes offset and collapsed(the maximum slightly higher than the detent point). It makes me think that what we are actually trying to achieve here with this calibration is a bipolar balance so moving the paddle to either extreme and back to the detent we can keep the maximum level at the detent position if that makes sense. Not sure what p-p voltage that would be in certain CS80’s, maybe closer to the CS60 values as Michael was experimenting with, but just my own theory.

Anyway�� Someone out there must be holding some secret Yamaha documents about this calibration between revisions though, I find it too strange how this particular calibration was so off in the CS80 I had here.

Greg C.

Re: Do we have a list off all the errors in the calibration manual?

yahoogroups@... (Michael Fuchs) — Mon, 11 Nov 2024 12:16:09 -0800

Hi Mike,

MFox here. :)

Just a few additional words. I was really struggeling with the resonance, it always collapsed when I dialed it to the specs, but not on every voiceboard, some made it collapse earlier some later. Joachim Wilson (also a member of this group) was able to push it further. In the end I decided to go with the of the CS60 procedure for the filter and maybe adjust it a little more towards the CS80 specs until it worked fine on every voice board. Not sure what sound nuance I am missing, but the good thing is it still sounds like a CS80. ;)

Not sure if Greg is also a member of the group, but he was also seeing this during his calibration and tried to figure out a solution. He was telling me, that he calibrated the HPF to 4.3V and then cycled back to the same note, rised the brilliance level all the way up and then back down to the center. There is a level loss, but it sounded in the end right to him. Maybe you can try out that approach.

Michael

Re: Do we have a list off all the errors in the calibration manual?

geegrinovero@... (Gustavo E.E. Grinovero) — Mon, 11 Nov 2024 11:15:43 -0800

Hello Mike, I have a CS-80 that repaired long, long time ago, more than 20 years....

I have the tech manual, but it is very far from me, now. to see it and go to the point. But I remember one thing that you can use. You are trying to calibrate a board that you have changed components, right?. So look for a pattern that repeats on boards that do not have suffered a modification and is ok. I suppose that having 16 OSCILLATORS, you could find some that are OK. I remember that some parameters are affected by the way you touch the keyboard.... so I build a simulator of the mechanism with relays (for replacing the switches) and 555 to simulate it in a predictable way.

GOOD LUCK!

Gustavo.

On 2024-11-11 10:20 AM, Scott Rodriguez via groups.io wrote:

Re: Do we have a list off all the errors in the calibration manual?

synthrodriguez@... (Scott Rodriguez) — Mon, 11 Nov 2024 05:20:52 -0800

Mike: For the CS-80, when referencing the Adjustment Procedure document, below is what I have learned about the typos and inaccuracies on the filter and vca adjustment docs and how I do it.

VCF - Complete Alignment - Page 11
Make sure to do the sustain level and attack adjustment procedures first.
When doing the adjustment, I use two trimmers at the same time and adjust the peak and gain pots simultaneously. Makes setting the High Pass filter quick and easy.

If you can't achieve the correct voltage settings (sometimes you can ALMOST get there, argh) then you have a bad chip. Good chips will easily hit the intended target level every time.

Item 1. The CP3 terminal reference is incorrect and should be CP2. I use CP7 however which is electrically the same thing; it's just easier to get at the way I do it.

The 4.3 Vp-p value is incorrect and is the zero-to-peak value. The correct value is double that and should be 8.6 V peak-to-peak to match the pictorial representation.

Item 2. The terminal reference of CP3 is incorrect and should be CP8. The 2.2 Vp-p value in the pictorial is correct.

VCA - Page 15

Make sure you have a good ground reference for the scope on the card itself. If using a rack mounting ear, make sure the screw is good and tight (which should be done anyway).
Item 2. VCA #2 Gain - As shown, but set both the BRILLIANCE and RESONANCE paddles on the main panel to the full forward (the low) position to achieve the correct wave shape.
Item 4. Output Terminal - Rather than using a scope for adjusting the output VCA to 80,mVp-p, use a good DMM and set it to dBm. Adjust the trimmer to a 28.3 mV RMS value. Much easier to do and more consistent between voices.

Also, lately I've been replacing the voice card 2SC458 output transistor with KSC1815 parts as I've seen several go bad. Drop-in replacement with a lower noise figure. Yamaha went to the 1815's for the CS-70M cards, fwiw.

Scott Rodriguez

11/11/24

CS-80 Coming Up For Sale -Borish Electroncs-

mborish_2000@... (mborish_2000) — Sun, 10 Nov 2024 20:46:32 -0800

I'm just putting the finishing touches on a CS-80 planned for sale in Chicago, IL USA. I've really gone over almost everything in this one. All new electrolytic caps, all new CMOS, full calibration, etc. Leg bag, lid and legs included. Pictures coming soon.

You can e-mail me at mike@... with offers if you're interested.

Thanks,

-Mike

Do we have a list off all the errors in the calibration manual?

mborish_2000@... (mborish_2000) — Sun, 10 Nov 2024 20:40:40 -0800

I'm asking this question basically to see how people have approached the filter and VCA tuning discrepancies in the service manual. I've read several different opinions on them, but have yet to find a consensus or a correct answer. I've got two CS-80s here right now to experiment on. One of them I probably calibrated somewhat wrong over a decade ago and could probably use a new calibration.

Here's the latest take:

https://mfoxhd.blogspot.com/2016/01/calibration-3-m-boards.html

Thoughts?

-Mike Borish

borishelectronics.com

Re: How long can your CS80 go until the need of recalibrating the oscillators?

tommykeyboard@... (Tommy's Keys) — Fri, 02 Feb 2024 08:35:41 -0800

Hi.

I have had 3 CS80s in the studio, once they have settled in for a few days, I do the complete calibration. I calibrated all three once a year, but just to get the beats the way I like them, otherwise they were playable without problems. In the last ten years I have only kept one, since I moved to the seaside, I thought I would have problems, but once the tuning has been done , I repeat it for my pleasure, just once a year.

Re: How long can your CS80 go until the need of recalibrating the oscillators?

scottmetzger@... (Scott Metzger) — Wed, 24 Jan 2024 12:10:49 -0800

Honestly it should have gone for more. Selling the dream of owning a CS-80 with a view of downtown Los Angeles is right out of the film Blade Runner. This experience is completely priceless.

Re: A 1981 Cs80 on ebay, with great mods made by Yamaha Usa.

cheater00social@... (cheater cheater) — Wed, 24 Jan 2024 11:47:28 -0800

yeah, given the post-scarcity market situation, even 5k is asking a
lot for this, given the massive amount of work every unit needs.

back when it was the only really good synth with poly AT, and the only
way to get a cs80 sound, it was worth a bunch more. but not anymore.
first, a lot of amazing analogs came out, which are objectively just
better than cs80. then, a bunch of very good cs80 VSTs came out, so
now the cs80 is the only way to get a cs80 sound *in analog*. then,
good clones came out, so the cs80 isn't the only way to get the cs80
sound... in any way. meantime, a bunch of very good polyphonic
aftertouch controllers and surfaces came out that went way, way beyond
what the cs80 can do on its... what, 3-bit? aftertouch. and finally,
synths with great performance controls that make the cs80 blush have
been around for a long time. meanwhile, the cs80s themselves have been
becoming more broken, more decrepit, and more difficult to find
replacements for. and the buyer's market *in general* for vanity
purchases has dried up. things that would fetch 100k-150k now go for
less than 10k (that's how I got my insane quad-amped PMC MB2 XBD
setup). people just don't have money at all anymore due to politicians
and billionaires stealing it all. the days of high synth (and, in
general, collectors' items) prices being possible to rationalize have
long gone, sailed away, and they aren't coming back for at least 20
years.

there's no scarcity. there's no value proposition. there are no
buyers. and there is no money.

Re: How long can your CS80 go until the need of recalibrating the oscillators?

fredrik@... (Fredrik Segerfalk) — Wed, 24 Jan 2024 11:40:24 -0800

Idk, I have tuned a few CS80:s, including my own, and they've all been very stable. I moved mine 6 floors (carry, no elevator) and it was perfectly in tune afterwards. I think it's just a story that has stuck for some reason.

Fred

Analog Sweden

24.01.2024 18:51 skrev Michael Fuchs:

Re: How long can your CS80 go until the need of recalibrating the oscillators?

@... — Wed, 24 Jan 2024 11:28:31 -0800

Hi All,

I am going to unsubscribe because I sold my CS80 a couple of years ago. I am not a tech and it was very needy and hard to move. FYI, I sold it for $47,000.00 to some film person out West.

Best of luck to all of you. These are amazing instruments.

Stan

From: [email protected] <[email protected]> on behalf of Scott Rodriguez <synthrodriguez@...>
Date: Wednesday, January 24, 2024 at 1:24��PM
To: [email protected] <[email protected]>
Subject: Re: [yamahaCS80fans] How long can your CS80 go until the need of recalibrating the oscillators?

If otherwise in well-calibrated and good operating condition, and in a stable environment, about once-a-year tuning is pretty typical. Much like a piano.

Re: How long can your CS80 go until the need of recalibrating the oscillators?

synthrodriguez@... (Scott Rodriguez) — Wed, 24 Jan 2024 11:24:02 -0800

If otherwise in well-calibrated and good operating condition, and in a stable environment, about once-a-year tuning is pretty typical. Much like a piano.

Re: How long can your CS80 go until the need of recalibrating the oscillators?

nightmusic01@... (Nightmusic) — Wed, 24 Jan 2024 10:29:06 -0800

Always been curious to install these multiturn pots in my CS80 too.

Could you possibly share the pots reference of the ones you installed in yours, Csaba?

Thank you,

Greg

Re: How long can your CS80 go until the need of recalibrating the oscillators?

czvekan@... (Csaba Zvekan) — Wed, 24 Jan 2024 09:53:15 -0800

I have installed all mutiturn Pots and it was stable even when you move things around.

Csaba

Re: How long can your CS80 go until the need of recalibrating the oscillators?

Iammichaelcarr@... (Michael Carr) — Wed, 24 Jan 2024 09:52:34 -0800

I have a cs80 that mostly works.

It needs some

Service.

It’s in New Jersey.

Is someone interested in buying it.

Email me here

How long can your CS80 go until the need of recalibrating the oscillators?

yahoogroups@... (Michael Fuchs) — Wed, 24 Jan 2024 09:51:14 -0800

Hi All,

since there seems to come back some life into the group, I was always wondering about one thing: Before I had a CS80 I was always reading about what a headache the machine is regarding staying in tune over time. Some technician even told me once that just by moving it around in the room detuned some oscillators.

I haven't made that experience. Actually I calibrated mine from ground up, which was quite a ride that will cost me a few years of my lifespan, but I learned a lot. I documented it, mainly for myself if I have to ever do it again :) , in case of interest : https://mfoxhd.blogspot.com/

Anyway, I calibrated mine in 2016, meanwhile I also moved to another apartment. I recently checked how good it is in tune and it is slightly detuned here and there, but it is not bad and I cannot really hear it when playing.

I wonder about my fellow CS80 owners what experience they make or made regarding this.

Michael

Re: A 1981 Cs80 on ebay, with great mods made by Yamaha Usa.

blacklagoon1881@... (Teo Halm) — Wed, 24 Jan 2024 02:40:56 -0800

woah. thanks Florian!

Re: A 1981 Cs80 on ebay, with great mods made by Yamaha Usa.

fanwander@... (Florian Anwander) — Tue, 23 Jan 2024 14:36:36 -0800

June 2022: 5200,- Euros, unserviced quite out of tune, scratchy trimmers, very unreliable switch contacts, but basically everything working. Not a single chip failure! I know both, the seller and the buyer (none of them is me). The synth still is before finishing.
"Investment" until now: 120 hours (done by the buyer). If you'd bill the usual hourly rate of a synth technician here in Germany that additional investment would sum up to around 10k - 12k Euros.

Am 23.01.24 um 22:53 schrieb Teo Halm:

Re: A 1981 Cs80 on ebay, with great mods made by Yamaha Usa.

blacklagoon1881@... (Teo Halm) — Tue, 23 Jan 2024 13:54:10 -0800

whats the lowest price you guys have seen a working cs-80 go for in the last couple years?

Re: A 1981 Cs80 on ebay, with great mods made by Yamaha Usa.

fanwander@... (Florian Anwander) — Tue, 23 Jan 2024 13:36:26 -0800

If there would be documentation for all those addons it might be interesting for lets say 15k. (10k for a only half working CS80, 5k for the super rare addons).
But guess why there were "a couple reputable shops[...]who said they didn’t want to work on it". If there is no documentation, then the only chance will be to remove all the addons and restore it into a working normal CS80.

Am 23.01.24 um 22:16 schrieb Teo Halm: