Yamaha CS80

I don't even get the list messages mailed to me anymore.
Switched to web-only mode, to concentrate on my current
projects.

Found your mails about harmonics in RM sine.

You made a Fourier analysis. What order of magnitude are the
levels of these harmonics? It's not unusual for "waveshaped"
(from other waveforms) sine waves to have something between
0.5% (quite good) and 3% (cheap, but quite usual) of THD.

3% means -30dB which seems high on a spectrum analyser, even
though it's pretty normal for that kind of stuff.

So in what order of magnitude were the harmonics you measured
in the CS-80 ?

JH.


> Juergen? Still no time?
> Thx for your reply.
> Max
> By the way: I looked back into some lists including the AH board 
but found
> nothing about the Chorus : does the ON/OFF switch arm the chorus 
without the
> LFOs modulation?
> M
> ----- Original Message -----
> From: "Max Fazio" <faxiomas@v...>
> To: <yamahacs80@yahoogroups.com>
> Sent: Sunday, January 22, 2006 1:16 AM
> Subject: [yamahacs80] Speed Modulation
> 
> 
> > Hi all
> > This is especially for Juergen.
> > I've been happy to read a nice discovery you made about the 
differences
> between amount and speed modulation in the CS80, I refer to your 
message on
> the Analogue Heaven board of October 16th, 2003;
> > Quoting
> > > You never stop learning - last night I read a CS-80 review at
> > > www.amazona.de , and suddenly learned that the smaller CS-synths
> > > are missing another fine detail of the CS-80: Sub Osc (LFO) 
speed
> > > modulation via aftertouch!
> > >
> > > Surprised that I never had noticed this before, a question
> > > was immediatly arising: The CS-80 has polyphonic aftertouch, but
> > > there is only one Sub Oscillator. So the CS-80 must also emulate
> > > monophonic aftertouch internally. I consulted the schematics, 
and
> > > found that there is in fact a set of diodes which creates the
> > > *maximum* of all individual pressure sensors, and uses this to
> > > control the LFO speed. As expected.
> > >
> > > But there's more, and this is where it may become interesting:
> > > The diodes cause a voltage drop of approx. 0.5V, and there is
> > > no compensation circuit for this. So I expect the LFO speed
> > > modulation to come *later* (at a higher threshold) than VCF / 
VCA
> > > modulation when you gradually increase the pressure on a key.
> > > This would allow some brilliance and volume modulation by
> > > aftertouch without LFO speed modulation at low pressure
> > > values, and LFO speed modulation joining in at higher pressure
> > > values. Which would be another very sensible choice for a great
> > > performance-type instrument.
> > >
> > > Can anybody confirm (or correct) this behavior?
> > >
> > > Now I know another mod I have to do for my CS-50 (;->)
> > >
> > > JH.
> >
> >
> > End of quote.
> > So what do you mean when you talk about the maximum number of 
pressure
> sensors involved with the Speed trigger of S-O? and what about the 
% of
> pressure that allows the trigger of the speed?
> > Thx fr your reply
> > M
> >
> > [Non-text portions of this message have been removed]
> >
> >
> >
> >
> > Yahoo! Groups Links
> >
> >
> >
> >
> >
> >
>