Re: YM26600/26700 IC Alternatives

开云体育

Beside what David said - yes, someone did it already: Ok, it is not for the polyphonic series, but it shows, that is doable, and also that it would provide other advantages, like adding MIDI.

On 16.01.18 18:39 , jonathan4051@... [yamahacs80] wrote:

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?

Has anyone ever looked into modern alternatives for these fragile and rare 40-year old chips? I am wondering if it'd be possible to program an Arduino to handle key coding/assigning and D/A conversion on the KAS and KBC boards.

Cheers,

Jonathan

Re: YM26600/26700 IC Alternatives

#4616

开云体育

Jonathan,

Duplicating the logic is easy. ?The big pain is the voltage. ?The Yamaha uses 4000-series CMOS and runs all the digital logic at +8.5 / -6.5 -> 15 volt supply. ?It’s offset above/below zero to interface with the analog circuits that run off +/- 15 volt. ?No modern chips run at this high voltage. ?Even 5-volt is history and 3.3-volt is only kept around for interfacing with older parts. ?All the chip guts these days are running around 1-volt. ? So, you end up needing tons of level-shifting chips to connect the Ardiuno (or FPGA) to the rest of the logic. ?Most circuits I’ve seen use chips that were intended for converting RS-232 (also fairly extinct) like the MAX232. ?The chips that were most commonly used won’t work anymore since they convert to +5v TTL.

?David

Show quoted text

On Jan 16, 2018, at 9:39 AM, jonathan4051@... [yamahacs80] <yamahacs80@...> wrote:

Has anyone ever looked into modern alternatives for these fragile and rare 40-year old chips? I am wondering if it'd be possible to program an Arduino to handle key coding/assigning and D/A conversion on the KAS and KBC boards.
Cheers,
Jonathan

YM26600/26700 IC Alternatives

#4615

Has anyone ever looked into modern alternatives for these fragile and rare 40-year old chips? I am wondering if it'd be possible to program an Arduino to handle key coding/assigning and D/A conversion on the KAS and KBC boards.

Cheers,

Jonathan

Re: CS-80 tech question: initial velocity problem on TSB board

#4614

I checked the voltages at the 4051 key input pins (13-15, 1, 2, and 5), and they do not look reasonable. Whilst healthy keys on other 4051's rest at 6V and approach 13-14V as you apply aftertouch, the bad keys are resting at 9.23V and jump to 15.49V as soon as they are hit, without even applying the aftertouch. The voltages on some of them slowly drop back toward 9.23 until you hit them again and they jump back to 15.49V. Odd.

Re: CS-80 tech question: initial velocity problem on TSB board

#4613

Hi David,

Thanks for the info and happy new year to you as well! This is actually the second time you've helped me, as I've been going by the CS-80 schematics and block diagrams from your website - thanks for uploading those!

I do have an oscilloscope, so will give it a whirl, and will try removing IC4 and see if pin 3 is still +15v. I'm also wondering what effect the TKC board has on the A, B, and C inputs of the 4051, and if that could be the culprit. One guy on Muffwiggler suggested a possible broken trace or wire going to the aftertouch PCB under the keyboard, and that if the -15v rail wasn't getting to this board, +15v at pin 3 could be the symptom. Another said to simply wiggle all the spider webs of wires going to the solder pads, as they can detach over time. So I have a few things to try. That thread can be found here: https://www.muffwiggler.com/forum/viewtopic.php?t=193847

For some reason, the last tech that serviced this board installed JRC 072BD's in place of the old 4558's. Am not sure if this is a common swap, but the design on their respective data sheets looked pretty close. Pin-outs are the same, just some subtle differences in the actual circuit.

Cheers,

Jonathan

Re: CS-80 tech question: initial velocity problem on TSB board

#4612

开云体育

Hi Jonathan!

Happy New Year and sorry about your CS80 problem. ?It sounds like you’re doing a good job trying to isolate the problem. ?However, I don’t know if you can do this with just a multimeter since the signals are multiplexed by the 4051. ?I think a cheap, used oscilloscope would really help. ?The fastest clock in the digital logic is only about 100KHz so even a 1Mhz or 10MHz.

If IC4, pin 3 is really stuck at +15v, that ?would give you max velocity (initial touch) and aftertouch on those 6 notes. ?What if you remove IC4 and leave the socket empty? ?Is it still +15? ?That would indicate a short on the board. ?If not, then your idea of the op-amp, IC7 having a problem could be it. ?Try replacing/swapping/removing that. ?It’s just a common 4558 dual op-amp. ?If it’s not one of those or a board short, I’m not sure what’s going on.

Good luck!

?David

Show quoted text

On Dec 29, 2017, at 11:27 AM, jonathan4051@... [yamahacs80] <yamahacs80@...> wrote:

Hello,
I am looking for technical help for a Yamaha CS-80. The issue it is having is: a cluster of six notes (G2 to C3) generate full volume at all times when keyed, no matter how softly they are played. I have traced the problem to IC4 (a newer 4051 multiplexer) on the TSB circuit board, and have tested the chip with a multimeter. The INH pin 6 is not stuck high and is toggling as it should. Pin 3 (Com in/out), however, is stuck at +15V for some reason, and I can't seem to figure out why. I believe this voltage should be around 5V as initial velocity is triggered and approach 15V as the poly aftertouch is applied. I tried swapping in another 4051 from IC3, and the problem remains exclusive to the IC4 socket and the same cluster of keyboard notes. I've also checked the solder underneath for shorts and opens and compared it to the other 4051's on the board and haven't found anything out of the ordinary. Does anyone have any idea as to where I should look next? Could the IC7 (a JRC 072BD dual op-amp, also a recent replacement of the original 4558) that pin 3 goes to be involved? Could a faulty TKC board component be causing the problem? Any help would be greatly appreciated. Thanks!
Cheers,
Jonathan

CS-80 tech question: initial velocity problem on TSB board

#4611

Hello,
I am looking for technical help for a Yamaha CS-80. The issue it is having is: a cluster of six notes (G2 to C3) generate full volume at all times when keyed, no matter how softly they are played. I have traced the problem to IC4 (a newer 4051 multiplexer) on the TSB circuit board, and have tested the chip with a multimeter. The INH pin 6 is not stuck high and is toggling as it should. Pin 3 (Com in/out), however, is stuck at +15V for some reason, and I can't seem to figure out why. I believe this voltage should be around 5V as initial velocity is triggered and approach 15V as the poly aftertouch is applied. I tried swapping in another 4051 from IC3, and the problem remains exclusive to the IC4 socket and the same cluster of keyboard notes. I've also checked the solder underneath for shorts and opens and compared it to the other 4051's on the board and haven't found anything out of the ordinary. Does anyone have any idea as to where I should look next? Could the IC7 (a JRC 072BD dual op-amp, also a recent replacement of the original 4558) that pin 3 goes to be involved? Could a faulty TKC board component be causing the problem? Any help would be greatly appreciated. Thanks!
Cheers,
Jonathan

Re: cannot seem to access CS80 group!

Murilo Faria

#4610

Thanks guys! Sorry about the mess! I don't use Yahoo Groups in a long time!

Bests,

2017-12-01 6:34 GMT-02:00 Florian Anwander fanwander@... [yamahacs80] <yamahacs80@...>:

Show quoted text

?

Jonathan sent this mail to my mail-account directly. I answered him the
following:
-----------snip-----------
Hello Jonathan

I am not the moderator, but your posting appeared on the groups list. So
appearently are subscribed and the address jw_dewdney@... is the
valid address.
The last postings were from Murilo Faria on november 21st.

Do you read the group as maillist or do you read it online in the browser?

Florian

-----------snip-----------
maybe the real group owner / admin can get in contact with him.

Florian

Am 01.12.2017 um 09:24 schrieb Jonathan Dewdney jw_dewdney@...
[yamahacs80]:
>
> Hi Florian - I think you are the moderator of the CS80 group?
>
> Do you know anything about changes to Yahoo's programming that has
> been causing problems? I do not seem to be able to access the CS80
> group - nor any other yahoo group i am a member of! Have you heard of
> this? Do you know if there's another way to access it (apart from the
> links in the e-mails)?
>
> I am using Firefox on an apple computer (since it became impossible
> for similar reasons to access yahoo groups on safari some time last year)
>
> thank you very much and sorry to bother you
>
>

--

--

Murilo Faria (Mura)

Re: cannot seem to access CS80 group!

#4609

Jonathan sent this mail to my mail-account directly. I answered him the following:
-----------snip-----------
Hello Jonathan

I am not the moderator, but your posting appeared on the groups list. So appearently are subscribed and the address jw_dewdney@... is the valid address.
The last postings were from Murilo Faria on november 21st.

Do you read the group as maillist or do you read it online in the browser?

Florian

-----------snip-----------
maybe the real group owner / admin can get in contact with him.

Florian


Am 01.12.2017 um 09:24 schrieb Jonathan Dewdney jw_dewdney@... [yamahacs80]:

Show quoted text

Hi Florian - I think you are the moderator of the CS80 group?

Do you know anything about changes to Yahoo's programming that has been causing problems? I do not seem to be able to access the CS80 group - nor any other yahoo group i am a member of! Have you heard of this? Do you know if there's another way to access it (apart from the links in the e-mails)?

I am using Firefox on an apple computer (since it became impossible for similar reasons to access yahoo groups on safari some time last year)

thank you very much and sorry to bother you

--

Re: cannot seem to access CS80 group!

#4608

Hello Jonathan

I am not the moderator, but your posting appeared on the groups list. So appearently are subscribed and the address jw_dewdney@... is the valid address.
The last postings were from Murilo Faria on november 21st.

Do you read the group as maillist or do you read it online in the browser?

Florian

Am 01.12.2017 um 09:24 schrieb Jonathan Dewdney:

Show quoted text

Hi Florian - I think you are the moderator of the CS80 group?

Do you know anything about changes to Yahoo's programming that has been causing problems? I do not seem to be able to access the CS80 group - nor any other yahoo group i am a member of! Have you heard of this? Do you know if there's another way to access it (apart from the links in the e-mails)?

I am using Firefox on an apple computer (since it became impossible for similar reasons to access yahoo groups on safari some time last year)

thank you very much and sorry to bother you

--

cannot seem to access CS80 group!

#4607

Hi Florian - I think you are the moderator of the CS80 group?

Do you know anything about changes to Yahoo's programming that has been causing problems? I do not seem to be able to access the CS80 group - nor any other yahoo group i am a member of! Have you heard of this? Do you know if there's another way to access it (apart from the links in the e-mails)? 

I am using Firefox on an apple computer (since it became impossible for similar reasons to access yahoo groups on safari some time last year)

thank you very much and sorry to bother you

Re: Request to join yamahacs80 approved

Murilo Faria

#4606

Thanks, Florian!

Glad you like my band :)

Yeah... I have the tech guy, but it's the only one and he is... fully booked. I'll have to wait and he is not fast (he took 4 years to "repair" part of it)... That's the problem. I really want to see the CS80 working.. I don't wanna trade, but things are getting boring now.

Thanks again, Florian!

Bests,

2017-11-21 10:48 GMT-02:00 Florian Anwander fanwander@... [yamahacs80] <yamahacs80@...>:

Show quoted text

?

Hello Murilo,

It is cruel to say, but I think owning a CS80 without having a competent
tech within reach does not make real sense.
When you say, that you had it repaired already, while you owned it, then
it sounds like a CS80-technician is availble basically at least.

So the question is: Is there no CS80-technician in Brazil at all, or is
it "only" difficult to get a repair session at him?

Whether a Arp2600 is a suitable exchange for a broken CS80 is
questionable. The ARP would have to be in absolute perfect shape
optically and technically. And still then it will be a loss. A perfect
ARP2600 is maybe worth $5000, the repair of the CS80 in the UK or the US
might cost $3000 or $4000 including shipping. And $8000-$9000 for a
restored CS80 is a very low price.

Florian

PS: just listening to your Giant Flea album
()
- very nice! This will fite nicely in my playlists with LCD-Soundsystem,

Am 21.11.2017 um 13:04 schrieb Murilo Faria muriloaof@...
[yamahacs80]:
> My name is Murilo from Brazil and I have a Yamaha CS80 for around 7
> years. In those 7 years it’s been through repair and now I have no
> sound out of it. The CS80 powers normally, but no sound… Only low
> noise (if I switch on the chorus, i can hear it affecting this noise)
>
> Brazil is a crazy country and we don’t have enough technicians to
> repair it… So, I’m wondering if you can help me in any way. I’ve
> already changed death master VCA (chip Ig00159) and nothing… Do you
> guys have any ideas?
>
> I have the possibility to change for a Arp 2600. I know is a different
> beast, but.... Should I?
>
> Just out of curiosity, what synth would exchange for If you guys were
> in my boots?
>
> Thanks In advance!!!
>
> --
> Murilo Faria (Mura)
> <>
>

--

--

Murilo Faria (Mura)

Re: Request to join yamahacs80 approved

#4605

Hello Murilo,

It is cruel to say, but I think owning a CS80 without having a competent tech within reach does not make real sense.
When you say, that you had it repaired already, while you owned it, then it sounds like a CS80-technician is availble basically at least.

So the question is: Is there no CS80-technician in Brazil at all, or is it "only" difficult to get a repair session at him?

Whether a Arp2600 is a suitable exchange for a broken CS80 is questionable. The ARP would have to be in absolute perfect shape optically and technically. And still then it will be a loss. A perfect ARP2600 is maybe worth $5000, the repair of the CS80 in the UK or the US might cost $3000 or $4000 including shipping. And $8000-$9000 for a restored CS80 is a very low price.

Florian

PS: just listening to your Giant Flea album () - very nice! This will fite nicely in my playlists with LCD-Soundsystem,

Am 21.11.2017 um 13:04 schrieb Murilo Faria muriloaof@... [yamahacs80]:

Show quoted text

My name is Murilo from Brazil and I have a Yamaha CS80 for around 7 years. In those 7 years it’s been through repair and now I have no sound out of it. The CS80 powers normally, but no sound… Only low noise (if I switch on the chorus, i can hear it affecting this noise)

Brazil is a crazy country and we don’t have enough technicians to repair it… So, I’m wondering if you can help me in any way. I’ve already changed death master VCA (chip Ig00159) and nothing… Do you guys have any ideas?

I have the possibility to change for a Arp 2600. I know is a different beast, but.... Should I?

Just out of curiosity, what synth would exchange for If you guys were in my boots?

Thanks In advance!!!

-- 
Murilo Faria (Mura)
aldotheband.com <>

--

Re: Request to join yamahacs80 approved

Murilo Faria

#4604

My name is Murilo from Brazil and I have a Yamaha CS80 for around 7 years. In those 7 years it’s been through repair and now I have no sound out of it. The CS80 powers normally, but no sound… Only low noise (if I switch on the chorus, i can hear it affecting this noise)

Brazil is a crazy country and we don’t have enough technicians to repair it… So, I’m wondering if you can help me in any way. I’ve already changed death master VCA (chip Ig00159) and nothing… Do you guys have any ideas?

I have the possibility to change for a Arp 2600. I know is a different beast, but.... Should I?

Just out of curiosity, what synth would exchange for If you guys were in my boots?

Thanks In advance!!!

--

Murilo Faria (Mura)

Re: Yamaha CS-60 issues: sub osc LFO > VCO not working + random bad notes

#4603

Thank you so much!! I found the toggle switch and flipped it other direction, and sure enough the LFO > VCO slider now affects the sound! :)?

Thankfully no fix is required... now to keep my eyes on the "bad note" problem and see if I can narrow it down...

Cheers

On Thursday, November 9, 2017, 9:21:10 PM PST, David Rogoff david@... [yamahacs80] wrote:

There should be a push button and a toggle switch. ?The instructions say to add them on the front panel below the tuning knob:

In the last few I’ve done, I’ve hidden then in the power cord compartment so I didn’t have to drill holes in the panel.

?David

Show quoted text

On Nov 9, 2017, at 9:11 PM, V CL virusindigo2@... [yamahacs80] <yamahacs80@...> wrote:

Thanks for the reply... do you mean the MIDI kit adds a toggle switch for LFO > VCO modulation? If so, where would I find that switch to change it back?

The seller showed me an emergency switch for MIDI off/reset in case of stuck notes, but never a toggle switch to control LFO > VCO modulation from sub oscillator.

On Monday, November 6, 2017, 9:27:30 PM PST, David Rogoff david@... [yamahacs80] <yamahacs80@...> wrote:
On Nov 5, 2017, at 9:32 PM,?virusindigo2@...?[yamahacs80] <yamahacs80@...> wrote:
Hi all,
I have a Yamaha CS-60 I recently acquired from a local seller that has MIDI kit installed.?
1. Upon testing I noticed the sub oscillator LFO > VCO slider does not work/effect the sound (however, LFO > VCF and LFO > VCA do work fine).?
What is the likely culprit for this and how easy is it to fix?
This is normal. With the added toggle switch one way, the slider works normally. With it the other way, the LFO -> VCO is control via MIDI mod wheel.

Re: Yamaha CS-60 issues: sub osc LFO > VCO not working + random bad notes

#4602

开云体育

There should be a push button and a toggle switch. ?The instructions say to add them on the front panel below the tuning knob:

In the last few I’ve done, I’ve hidden then in the power cord compartment so I didn’t have to drill holes in the panel.

?David

Show quoted text

On Nov 9, 2017, at 9:11 PM, V CL virusindigo2@... [yamahacs80] <yamahacs80@...> wrote:

Thanks for the reply... do you mean the MIDI kit adds a toggle switch for LFO > VCO modulation? If so, where would I find that switch to change it back?

The seller showed me an emergency switch for MIDI off/reset in case of stuck notes, but never a toggle switch to control LFO > VCO modulation from sub oscillator.

On Monday, November 6, 2017, 9:27:30 PM PST, David Rogoff david@... [yamahacs80] <yamahacs80@...> wrote:
On Nov 5, 2017, at 9:32 PM,?virusindigo2@...?[yamahacs80] <yamahacs80@...> wrote:
Hi all,
I have a Yamaha CS-60 I recently acquired from a local seller that has MIDI kit installed.?
1. Upon testing I noticed the sub oscillator LFO > VCO slider does not work/effect the sound (however, LFO > VCF and LFO > VCA do work fine).?
What is the likely culprit for this and how easy is it to fix?
This is normal. With the added toggle switch one way, the slider works normally. With it the other way, the LFO -> VCO is control via MIDI mod wheel.

Re: Yamaha CS-60 issues: sub osc LFO > VCO not working + random bad notes

#4601

Thanks for the reply... do you mean the MIDI kit adds a toggle switch for LFO > VCO modulation? If so, where would I find that switch to change it back?

The seller showed me an emergency switch for MIDI off/reset in case of stuck notes, but never a toggle switch to control LFO > VCO modulation from sub oscillator.

On Monday, November 6, 2017, 9:27:30 PM PST, David Rogoff david@... [yamahacs80] wrote:

On Nov 5, 2017, at 9:32 PM, virusindigo2@... [yamahacs80] <yamahacs80@...> wrote:

Hi all,
I have a Yamaha CS-60 I recently acquired from a local seller that has MIDI kit installed.?
1. Upon testing I noticed the sub oscillator LFO > VCO slider does not work/effect the sound (however, LFO > VCF and LFO > VCA do work fine).?
What is the likely culprit for this and how easy is it to fix?

This is normal. With the added toggle switch one way, the slider works normally. With it the other way, the LFO -> VCO is control via MIDI mod wheel.

2. I notice after getting the synth home and playing it for awhile, that intermittent random bad notes would happen when playing the keys. It doesn't seem to matter what keys and it seems to happen randomly... ie after a few minutes or after 20 minutes.?
Any suggestions on where to look for fixing this/effort required would be most welcome. I'd need to take it to a tech and hoping it won't be an expensive fix.

That's not normal :( ? Unfortunately, nothing obvious comes to mind. ?I’d try contacting Kenton and see if they’ve heard of this.

?David

Re: Yamaha CS-60 issues: sub osc LFO > VCO not working + random bad notes

#4600

开云体育

Hello

On 06.11.17 06:32 , virusindigo2@... [yamahacs80] wrote:

? 2. I notice after getting the synth home and playing it for awhile, that intermittent random bad notes would happen when playing the keys. It doesn't seem to matter what keys and it seems to happen randomly... ie after a few minutes or after 20 minutes.?

.

Sounds like? a voice getting out of tune.

Might be a bad trimmer, but more likely a VCO chip dying.

I recommend to add a LED to each voicecard, with which you can detect, which voice is used:
Touching the trimmers for the tuning is another method, but it is quite tiring.

I am sure you will finde the culprit soon.

Florian

Re: Yamaha CS-60 issues: sub osc LFO > VCO not working + random bad notes

#4599

开云体育

On Nov 5, 2017, at 9:32 PM, virusindigo2@... [yamahacs80] <yamahacs80@...> wrote:

Hi all,
I have a Yamaha CS-60 I recently acquired from a local seller that has MIDI kit installed.?
1. Upon testing I noticed the sub oscillator LFO > VCO slider does not work/effect the sound (however, LFO > VCF and LFO > VCA do work fine).?
What is the likely culprit for this and how easy is it to fix?

This is normal. With the added toggle switch one way, the slider works normally. With it the other way, the LFO -> VCO is control via MIDI mod wheel.

2. I notice after getting the synth home and playing it for awhile, that intermittent random bad notes would happen when playing the keys. It doesn't seem to matter what keys and it seems to happen randomly... ie after a few minutes or after 20 minutes.?
Any suggestions on where to look for fixing this/effort required would be most welcome. I'd need to take it to a tech and hoping it won't be an expensive fix.

That's not normal :( ? Unfortunately, nothing obvious comes to mind. ?I’d try contacting Kenton and see if they’ve heard of this.

?David

Yamaha CS-60 issues: sub osc LFO > VCO not working + random bad notes

#4598

Hi all,

I have a Yamaha CS-60 I recently acquired from a local seller that has MIDI kit installed.?

1. Upon testing I noticed the sub oscillator LFO > VCO slider does not work/effect the sound (however, LFO > VCF and LFO > VCA do work fine).?

What is the likely culprit for this and how easy is it to fix?

2. I notice after getting the synth home and playing it for awhile, that intermittent random bad notes would happen when playing the keys. It doesn't seem to matter what keys and it seems to happen randomly... ie after a few minutes or after 20 minutes.?

As an example, if I'm playing a scale and I hit one of the keys (ie a middle C), that will give a severely out of tune note. Coming back to the key immediately after and its in tune again.?

Any ideas what could cause random bad note behaviour across the keyboard? It doesn't seem to be a specific voice, but I have no idea what is triggering a bad note to occur randomly. Perhaps the MIDI retrofit messed something up, or when the synth was transported to my place the voice cards got jiggled around from bumpy driving?

Any suggestions on where to look for fixing this/effort required would be most welcome. I'd need to take it to a tech and hoping it won't be an expensive fix.?

Thanks.