[sdiy] top octave gneration

[John L Marshall]

I used a divider chain and a diode matrix for a mono synth. It was published
in Electronotes as a TTL Digisyntone, issue #13. I think Burhans Digisyntone
used RTL.

My original circuit used eight flip-flops which is a marginal match to the
tempered scale. Nine flip-flops provides a dramatically closer match to the
tempered scale. I'll try to find a divide by list for nine then post it
here.

John


----- Original Message -----
From: harry bissell <paia2720 at yahoo.com>
To: <adam at hoodmusic.net>; <synth-diy at dropmix.xs4all.nl>
Sent: Tuesday, November 20, 2001 11:00 AM
Subject: Re: [sdiy] top octave gneration


> Hi Adam...
>
> There is no reason not to do it that way. I don't know
> about the long term stability of the 555 timers...that
> may be a real concern. You could make them easily
> adjustable and tune them with a musical instrument
> tuner every gig... Hey guitar players do it.
>
> An other approack would be to make your own Top Octave
> Generator.  You pick an integer series that
> approximates the 12th root of two (equal tempered
> scale).. Some old Journal of the Audio Engineering
> Society issues had Ralph W. Burnhams (sp?) approach...
>
> Some folk would suggest using a PIC mirco to do
> this...
>
> H^) harry
>
>
>
> --- adam at hoodmusic.net wrote:
> > hi
> >     i have been thinking about building an organ or
> > string synth for
> > awhile now and i was thinking of useing a few quad
> > 555 timers to create
> > the top octave and then divide it down for the rest
> > of the notes. would
> > there be any problems in going about it in this
> > method? or would there
> > be a better way to go about?
> >
> > adam
> >
> >
> >
>
>
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