Yamaha CS01 New Hybrid Waveforms Modification

[SHUJINCELL]

Sick.

[rga24yt]

Hi, I would guess you are generating the new waveforms by connecting more than one of N2, N3, N4 and N5 to the F signal, is this correct? I have done some modifications of my own to my CS01 and would like to add these extra waveforms to my machine, especially the final waveform!

[rolandsh1000]

@rga24yt

Pretty much that's it. If you email me, I can tell you what the various shortings are...or you can figure them out on your own - not too much testing involved.

What mods have you done to your CS01?

[rga24yt]

@rolandsh1000 OK, at a guess they are Triangle & Sawtooth together, Triangle & Square, Sawtooth & Square. Any that use PWM?

I'm about to write a blog post about my CS01:

10k pot for resonance added

3 position switch added for modulation wheel source - LFO (as standard), VCO or Noise, assignable to VCO or VCF

3 position switch added for breath control modulation source - as above, but available on the breath control VCF and VCA knobs

Old resonance switch now EG / Gate selector for VCA.

[rga24yt]

@rolandsh1000 Hi, I've just done the mods on my CS01. I used diodes between the signals on the board and the new switches, so that my circuit doesn't have the caveats you mention. You can get 4 useful new waveforms, plus 3 waveforms based on the pulse wave setting that sound pretty much like pulse itself, 7 new waveforms in all, at all footages.

[rolandsh1000]

@rga24yt

Excellent!!! I hadn't considered using the diodes so that's a terrific addition, makes these waveforms now equivalent to stock performance.

Love to see how you laid out the switches and the pots - to me that might be the most challenging part of all, given the very tight space in the CS01. Care to post a video, or send me pics? Better yet, send pics to Matrixsynth so he can post them and CS01 owners will be wanting to do these mods.

Again, great work!

[rga24yt]

@rolandsh1000 I wrote up the mods I did and published them as a blog post. Hopefully Matrixsynth will pick up on this; I can't post URLs in YouTube comments.

[rolandsh1000]

@rolandsh1000

sounds great.

I hear you on the no-URL-in-Youtube, but can you type some keywords so I could google your blog?

[he214ab]

i wanna own one cs01 as well.

[deeJayfirby]

See you have talent. You should consider building a synth from scratch. Just think about it. Put yourself into some risk to put yourself ahead.

[rolandsh1000]

Thanks for the compliment. I am much more a person who modifies things rather than creates them whole, so I'll leave creating a synth from scratch to others.

My most ambitious projects have been to take sections of dead or parted-out synths and to reconstruct them into different things. Perhaps I'll post my Sixtrak-DW6000 hybrid synthesizer sometime.

Thanks again!

[nathanielscott]

CRAZY SWEET!!!

Thank you so much for posting this. I have been looking for a schematic of the osc chip in the CS01. I am heading to your site right now!

[nathanielscott]

Except now I cant find your website.

[rolandsh1000]

Hi,

sorry - I haven't posted it to my site yet!

and I hope you're not disappointed, but there is no existing schematic/datasheet of the YM1015 or YM1037 that I'm aware of. all that I've ever seen is the schematic for the CS01. that IS available on the web somewhere.

I will try to post my mods to my site in the next week or so, though...

[nathanielscott]

Thanks for the reply. I have been looking around for the CS01 schematics and am unable to find them. Do you remember where you saw them?

Also, do you know if there are any YM1015 or YM1037 chips around?

[noddyspuncture]

Digital tone generator chip..? Doesn't the CS01 use the same VCO chip that the other CS series use? The IG00153..?

[rolandsh1000]

the CS01's I've seen use the YM1015 or YM1037 for the oscillator, which is a combination key strike decoder/waveshaper chip (see the schematic).

someone suggested to me that the waveshaper part is like the CEM3396, where a high frequency squarewave is fed to the chip and determines the pitch of the waveform. the chunky waves I get out of mine above do suggest some sort of wavetable readout that's getting scrambled. maybe it is digital, but very high resolution > "analog"

[nickgash]

that's fantastic. i'd like to see a picture of the circuit board on that thing. i always thought the synthesis on the cs-01 was analog.

[Tplkkvkk]

it is