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Subject: Re: Enabling portamento mono mode

From: "devetron" <devetron@...>
Date: 2007-12-10

I, for one, would prefer to retain the chord memory mode. I like use
it for playing 2-3 octaves of the same note in mono with one finger.
It looks like you are leaning towards keeping it after all. Thanks
for all your hard work.

--- In korgpolyex@yahoogroups.com, "korgpolyex800"
<korgpolyex800@...> wrote:
>
> I could rewrite the code to toggle between Poly and mono mode using
> the Poly key. Another way might be to make the Poly key the selector
> for Poly, Mono, Chord and Hold mode. Each time you press the poly
key
> would move you into the next mode. That would free up the chord and
> hold buttons to be used for selecting global mode and extended
> parameter entry modes (or other things if we decide to add more).
>
> What do you all think?
>
> I managed to finish the pitch "bending" part of the mono mode
> portamento last night. Unfortunately, the results are not as good
as I
> had hoped for although I was not completely surprised at the result
> that I got. The method I used to simulate portamento was to use
pitch
> bend (which is a true analog bend) to slide one semitone up or down
to
> track towards the new note. Once the bend has moved the TG half a
> semitone, the DCO's are reprogrammed to change to the note above or
> below while simultaneously the bend is reset back to zero. This
would
> give the portamento effect by ramping the bend a semi tone and
quickly
> switching DCO semitones.
>
> Well it works, and it gave me great joy to hear it working, but
alas,
> resetting the bend is a little slow and you can clearly hear the
> oscillator output has a little glitch each time that the semitone
note
> change occurs. I now need to determine if the glitch is caused by
the
> master clock being incapable of tracking the output of the DAC when
a
> square wave edge change occurs in the bend or if the DAC sample hold
> circuit is too slow. If it's just the sample and hold then I may be
> able to reduce the sample hold capacitor to improve the highest
> possible rate of change. If it is due to the master clock not being
> able to change frequencies fast then I think we might be out of
luck.
> So much so that the only way to get good portamento would be to
build
> a new master clock that was able to slide the full five octaves.
>
> Mike.
>