Polyphonic NE555 instrument - Revisit

I play it at 3:10
About half a year ago I finished my 48 NE555 polyphonic organ/synthesizer. I also concluded that a couple of things could be improved, and that is what I try to do in this video.'
There was a very noisy potentiometer that I managed to get working. Four notes had a longer sustain that the others - I didn't mention that in the original videos but since I can correct this I might as well do it. Finally I add a gate output so I can control external envelope based circuitry from the keyboard. I also tried to make it less noisy, but I wasn't able to do so.
The music is a little whatever-it-is that I put together primarily to explore the automatic duet function on my Technics SX-EA5 organ, but it came out pretty well so I made it into a finished arrangement.

[@Metamerist625]

This looks and sounds great, nice work!

[@corrosiveabuser]

A quality sounding instrument, very noice.

[@marcbrasse747]

Excellent mod. I am sure I suggested a sort of paraphonic solution before and this is the perfect one. The fact that all the oscillators already have their individual amplitude releases makes it a Polymoog style hybrid. Why not create a corner with all your own builds combined into a modular system? All that stuff is something to be truly proud of. 👍👍👍

[@organfairy]

Wasn't Polymoog sort of an organ tone generator, with polyphonic synthesizer envelopes, but paraphonic filters..... or is it something I have misunderstood?

[@AndrewBeals]

This would be such a fun build!

[@organfairy]

It was fun - but also a little exhausting as each key has two separate tone generators and envelope systems.

[@Jonas_Keunecke]

Super cool, it sounds great. Maybe one day I'll know enough about electronics to try something like that

[@jocimusician]

Great! Do you have the schematics?

[@BadChizzle]

Nicely done.👏🏼

[@timothyverbist5795]

Nicely done, maybe you also may want to make a 4 octaves synthesizer.

[@bearshield7138]

very cool

[@PracticalCat]

Sounds bloody fantastic! Great job. So this has 48 555s? Mine has 36 (3 Ranks) I have to go watch your vid to see how you implemented them. Cant wait to add my vcf and vca to my synth project.

[@organfairy]

The short answer is that I use two for each of the 24 notes to give a detuning effect.

[@PracticalCat]

@organfairy Oh so its two osc per key rather than divide down?

[@organfairy]

@@PracticalCat There are two identical oscillator systems where the top octave is oscillators and the bottom octave is dividers. So 2 sets of 12 oscillators and 2 sets of 12 dividers.

[@PracticalCat]

@@organfairy Just rewatched your prev video. I get it now. I think the farfisa compact did something similar i.e. it didnt use flip flops for dividers but instead used non retriggering monostabe multivibrators. I may be wrong though.

[@organfairy]

@@PracticalCat That is quite possible. Before there were integrated frequency dividers, division had to be done with transistors (and before that valves or neon lamps). Dividers and monostables both requires two transistors so from a component count perspective there is not much difference. Monostables have the advantage, that they usually give a non-symmetrical squarewave, which is actually better from a musical point of view than the 50-50 squarewave from a divider.

[@daneguitarist1]

sublimes santeria right? haha nice

[@organfairy]

Not intentional. I didn't know that song.

[@daneguitarist1]

@@organfairy haha well its awesome! keep it up haha

[@csuhaitibor4339]

Nekem tetszik. Hogy lehet kibőviteni 5 oktávra ?

[@organfairy]

That would be quite a task. Each key has a complete tone generator and envelope circuit so to make a 5 octave version would more than double the amount of components. That was also the reason why I only made 2 octaves.