Hello,

first all, thank you for approval of my membership in the group.

I'm a owner of a CS50, that I purchased recently. The synth need a complete
calibration, and I want to ask you what is the best documentation to do this.
I've seen that there is an adjustment procedure document for the CS80, but
I haven't found a similar document for CS50. For what I've understand some
parts are common in the two synths (e.g. the Voice cards), but I'm not sure
if it is correct to follow the adjustment procedure described in the CS80 doc.

Thank you very much for your help!

Roby
(Italy)

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Hello Roby,

get the service manual for the CS-50: it contains a complete adjustment procedure.





or


(don't get worried about the cs80 naming of the sub folder)

Florian


On 20.10.17 22:01 , roby.mx@... [yamahacs80] wrote:

Hi Roby,
I followed the cs80 guidelines and it was pretty straight forward. Calibrating 4 voices isnt so bad! The trick is to follow tje voices as they cycle through. Each time.you powerup the unit it resets to voice one.
I didnt have a plastic mini screwdriver so i cut down a wooden chopstick and used that.
Good luck!
Colin

Tom S. from this list originally ran me through this process. This is my version of his notes (thanks Tom!)

You can probably skip sections 1 and 2: the 4volts on the KAS board and the '0'volts on each individual 'M' board. Try first to go straight for the tuning procedure.

The 'M' board tuning is mainly done with the VR3 and VR2 - this is a VERY important part. This is the SCALE or SPREAD of the keyboard from one end to the other. You MUST understand this. It is very similar to setting the bridge on a guitar where the distance from either end where the strings are need to be exactly the same distance from the 12th fret.

Instructions (The following is done FOR EACH VOICE CARD - separately):

Plug your output into a tuner
Turn on the synth and let it warm up - at least 20 -30 minutes before starting.
Use the FLUTE patch or the panel. If the panel, turn everything off and just use sine wave with an envelope set to sustain it as long as I have a key pressed.
Set to Oct Up position
Center the tuning knob
Play a high note - the Yamaha service notes say a high C, but you could use the highest A for example.
Use a plastic/ceramic trimmer - not a metal screwdriver - as it will affect the pitch. You can get plastic trimmers from electronic wholesalers etc. You can also make one by cutting an old credit card etc.
As long as in the highest transposition you adjust VR3 (little blue multi-turn preset) on a note at the HIGH end of the keyboard
Then adjust VR2 while playing a note on the LOWER end of the keyboard, again, 'C' or 'A'.
Remember - it is the SCALE or SPREAD you are adjusting here. Every adjustment will affect the other one, and you will need to go back and forth between high note (VR3) and low note (VR2) until no more adjusting seems necessary.
Then move on and do the same for the other transpositions.

I am assuming here that you know and understand how to establish which voice card is playing. I usually switch the synth off and on again. My CS makes a little beep sound when it is ready to go. The first key hit will be voice card 1. If you get lost, switch off and on again, just to make sure.

To get voice 4 (for example) hit one key 3 times, then hold the third hit down while simultaneously adding the next note for voice 4. Release key for voice 3. Continue holding voice 4 and tune your trimmer while doing so

One point - the Yamaha manual says you can TOUCH the track to hear the distortion, so you know which voice card you are on.... DO NOT DO THIS .... you could blow the VCO chip!!!!! Turn off/on... voice 1 is the first note pressed. Sometimes you will hear a slight distortion as you put your hand - or screwdriver - near the presets - but DO NOT try to touch and tracks on purpose...! Static can kill chips.

best - DT

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Hello

On 21.10.17 00:49 , ColinMuirDorward colindorward@... [yamahacs80] wrote:

?

?The trick is to follow tje voices as they cycle through. Each time.you powerup the unit it resets to voice one.

There is simple help for this. Add a LED driven by the gate of each voicecard:

Someone once said, this might affect the behaviour of the Gate drivers, but I did not measure any significant influence.

Florian

Hi Colin,

thank you for your advice!

Roby

Hi Florian,

Thank you for your reply.

Bye!
Roby