tube synth diy

Looking at some divide by two circuits:

I haven't had much luck prototyping the Pentode van der Pol type circuit nor the single tube pentode trigger circuits - yet. I think the key may be to use a negative supply to bias the suppressor (which I haven't done yet, and isn't always theoretically necessary).

Anyhow I'll scan in some examples. Anybody gotten a good trigger or relaxation oscillator with the van der Pol model? It looks like this was the method of creating sub-octaves on the Hammond Novachord.

Regards,

Lorin E. Parker

Hi Lorin
uploaded a chapter from Puckle's Time Bases, which discusses van der Pol's cct and introduces a number of ccts developed from it.
Hope it helps!
http://launch.groups.yahoo.com/group/tubesynthdiy/files/Puckle/

--- In tubesynthdiy@yahoogroups.com, "Lorin Edwin Parker" <parker@...> wrote:
>
>
> Looking at some divide by two circuits:
>
> I haven't had much luck prototyping the Pentode van der Pol type circuit nor the single tube pentode trigger circuits - yet. I think the key may be to use a negative supply to bias the suppressor (which I haven't done yet, and isn't always theoretically necessary).
>
> Anyhow I'll scan in some examples. Anybody gotten a good trigger or relaxation oscillator with the van der Pol model? It looks like this was the method of creating sub-octaves on the Hammond Novachord.
>
> Regards,
>
> Lorin E. Parker
>