[sdiy] Help deducing the internal resistor values of the IR3109?

[cheater00 .]

On Tue, Oct 8, 2013 at 12:06 AM, Jack Jackson <jackdamery at hotmail.co.uk> wrote:
> I built up half of the IR3109 schematic using 470ohms for the internal resistors. It made a pretty tasty filter and sounded very much like IR3109. I used the external capacitor and resistor values from the Jupiter 8 schematic. Unsurprisingly I implemented it with a LM13700 for the gain cells, TL072 for the two buffers instead of the 13700s internal buffers, and used the standard Thomas Henry current source expo converter made with another TL072
>
> Here it is:
> https://soundcloud.com/dot/ir3109-12db-ota-build
>
> Compare to my recording of the real IR3109:
> https://soundcloud.com/dot/ir3109-jupiter-filter-made

Sounds great. How are you on resonance stability?

Cheers,
D.