[sdiy] Interesting article on top octave generators.

[Roman Sowa]

Keeping the oscillators from syncing to each other is not that difficult.
Of course when done carelesly will happen for sure. That was my first 
attempt to make combo organ as a teenager. I happily made 12 oscillators 
on a single board, even made distributed octave dividers along the 
keyboard, and it devastated me when after PCB assembly all I got was 
maybe 2 or 3 frequencies coming out. Those 12 oscillators were working 
in sync. BTW, I think the dividers synced to each other too, which was a 
shock for me.

However, with a bit of common sense, it's possible. One example is 140 
oscillators on one big board made for very old (tube only) electronic 
pipe organ. Or another which I was refering recently - 12 semitone 
oscillators made with two 40106 and they do not sync at all. Not to 
mention my modular quad oscillator made on single board with single 
2164, or dual VCO module I helped with - my friend was feeling exactly 
like me, with that 12-osc attempt as his module intermodulated and 
synced heavily. With few simple tricks it's now rock solid.

Roman

W dniu 2024-12-31 o 17:47, Gordonjcp pisze:
> On Tue, Dec 31, 2024 at 03:48:36PM -0000, Richie Burnett wrote:
>>> Also, a board with twelve oscillators...
>>
>> ...would be quite prone to suffering entrainment of at least some of the
>> oscillators if they are high-frequency and free-running, unless they are
>> properly isolated from each other and the supply is decoupled thoroughly.
>>
>> -Richie,
> 
> I never even thought of that, but there would have to be massive decoupling otherwise yes, you would end up with a bunch of notes all sounding the same pitch, or going all croaky as they randomly jump between locked and unlocked.
> 
> I bet drone musicians would love it though.
>