[sdiy] Interesting article on top octave generators.

[Michael E Caloroso]

TOG or discrete dividers from a single master oscillator aren't going to
produce a perfect equal tempered scale because the interval between equal
tempered semitones isn't an integer ratio (the interval is an irrational
number = 12th root of 2).

If you want a true equal tempered scale, you have to use twelve tunable
oscillators per semitone.

MC

On Fri, Dec 27, 2024 at 4:09 PM Tom Wiltshire <tom at electricdruid.net> wrote:

>
> On 27 Dec 2024, at 20:17, Ingo Debus via Synth-diy <
> synth-diy at synth-diy.org> wrote:
>
> Am 27.12.2024 um 08:35 schrieb Donald Tillman <don at till.com>:
>
> If it was me, I would have directly emulated the chip with, say, 6
> CD4040's and some diodes.
>
>
> That’s what Elektor did in 1974:
> https://www.elektormagazine.de/magazine/elektor-197411/55706
>
> They used TTL chips, not CMOS. It was quite a huge project. I remember
> this so well because this was one of the first Elektor issues I bought
> myself.
>
>
> I honestly don't see the point of this type of approach. Discrete dividers
> has all of the worst features of the TOG chips (locked frequencies, poor
> frequency tuning, loads of circuit) without the few minor benefits (small
> size, simplicity, and cheapness).
>
> IF you'Re willing to throw that much circuitry at the problem, why would
> you *not* simply build a board with twelve top octave oscillators and then
> just use dividers from there? I don't get it.
>
> I suppose the draw of only having a *single' trimmer to tune the entire
> thing must have seemed absolutely magical in the late 1970's, and that was
> enough!!
>
> Tom
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