Hi everyone, I hope you are all well.
I have strange behavior on my CS-80. On the fourth voice (therefore cascading on both M14 and M24 cards) there is a portamento that occurs as soon as I press the key .. if I stay on that key and continue to play (therefore switching on the other voices) when I pass through the fourth voice nothing happens and the behavior is normal .. if instead I change the note as soon as I return to the fourth voice (so on M14-M24) here is the portamento! I state that the portamento is disabled, on the CS-80 all the old CMOS, OP-AMPs, ELECTROLYTIC CAPACITORS and TANTALUM have been changed. The problem, given the behavior, I would say that it is before of the two M cards. I checked the values on the KAS, on the S / H and in doubt also on TRG4 boards (I wanted to remove the doubt that it wasn't an initial-pitchbend problem, but in this case it should have always been portamento on the fourth voice, right?). The values on these boards are the reference values for the calibration .. Where could I inquire? Could it be a problem with some RC network?
Thanks anyway for your time!

Hi,
Do you get both upwards and downwards portamento?
Also can you confirm that the Portamento-Glissando white slider is set all the way down to Short (which is what turns the Portamento-Glissando effects off in the YM26700).
Joachim

On Thu, Sep 15, 2022 at 07:52 AM, Joachim Milson wrote:

Hi,
Do you get both upwards and downwards portamento?
Also can you confirm that the Portamento-Glissando white slider is set all the way down to Short (which is what turns the Portamento-Glissando effects off in the YM26700).
Joachim

Hi Joachim,
thanks for your answer.
Yes, the Portamento/Glissando is off (all the way down),?also because I believe that if this were not the case the behavior would be on all voices and not only on the voice 4. I also confirm that this strange behavior occurs upwards and downwards (and only when I change note -therefore voltage- but not if I stay on the same note).

Hi Bof bof,

That's strange indeed.
If you set the Portamento-Glissando rocker switch to Glissando while keeping the Portamento-Glissando white slider to short, do you get stepwise variations or is it still smooth?
To help locating the source of the problem, you could try and probe at K4 (just behind the buffer) on the KAS board while playing. If the pitch signal there varies in time, the problem would most certainly be on the KAS.

Joachim

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Portamento or Glissando switch doesn't change the result. But?look below (we are on the S&H board outputs). One is terminal K3 and the other is K4, the one with the problem .. guess which one is!). I apologize for the quality of the signal detection, but I think it can be seen quite clearly.. I then checked the outputs 3 and 4 of the KAS board and they seem ok. So I hope the problem is right on the S&H. I am going to check that this is the case, I keep you updated hoping that it can also be useful to someone else.

Hi Florian, thank you for your suggestion!
I investigate the S&H and if I find nothing I go and see.

The suspects on the S&H board were the CMOS 4011 or 4016. In the end it was a 4011, it wasn't completely faulty but in the end it made this good joke! Problem solved (I hope!).
Thank you all guys!

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Thanks Florian.?
I believe it when you talk about 4011... Among other things, it's not the first time that I happen to see a CMOS that apparently work but don't work completely correct. Then when I think about what they contain I understand that they can also behave like this!

I completely agree Tommy.
As I said above, I had already replaced them all (and not with Chinese sub-brands)