Re: [sdiy] cs 10 pitch

[Roman]

don't know about cs10, but cs15 has wooden bottom, so it should be no problem. AFAIR if you connect anything to CV inputs, the the keyboard and pitchbender are disconnected from VCO.
I suspect that somewhere on the way there's saturating opamp, so forcing lower CV has no effect on VCO chip. Track all CVs in the synth and see if they don't exceed, say, +/-10V.
Check also if you have correct voltages from keyboard. CS10 uses scanning keyboard and resistor divider strings. One for octaves, and second for semitones. Maybe some octave resistors are loose, or broken, or micro has faulty I/O pins and can't use the dividers properly.

Roman

---- Wiadomość Oryginalna ----
Od: Rude 66 <r.lekx at chello.nl>
Do: synth-diy <synth-diy at dropmix.xs4all.nl>
Data: Thu, 29 Apr 2004 14:16:06 +0200
Temat: [sdiy] cs 10 pitch

>hello all,
>
>i still have a problem with my yamaha cs10 that's starting to baffle me. i
>got this thing with the keyboard hacked off and in bits and pieces. there
>was no bottom anymore either. i mounted the power supply and regulator board
>on a piece of wood, and screwed this to the bottom of the cs10, figuring i'd
>use it as a desktop.
>so far, so good: it's a little scratchy, but it works via cv/gate. the
>problem is the pitch. even though it has a Feet selector which goes to '64'
>it won't go lower than what's about a c2. anything below that on the midi
>keyboard holds just one pitch. the pitch bend and modulation slider won't
>work either, despite being wired properly. when the cv/gate inputs are
>disconnected, when i touch the sliders i hear sound. even when i touch the
>wires to the sliders.
>
>all the wiring seems to be ok, and sometimes the pitch slider will work when
>i hold it, but moving it will make tpitch disappear. this makes me think of
>a ground problem.. is it possible that the wooden bottom is causing the
>ground not to work properly? the funny thing it it will go lower in pitch,
>but only using the midi pitch bender on the master keyboard..not the keys.
>go figure.
>the midi-cv is a syntecno teebee.
>
>any ideas? it's a nice synth, and i can hear the bass potential in it..;-)
>
>thanks!
>
>ruud
>
>