How do you LP wo/caps?

[patchell]

    Well, sort of.  You can make a filter using programable opamps that
need no external capacitors, but what they do is make use of the
internal compensation capacitor, so, in reality, it does have capacitors
it it.  You are probably making use of the frequency response of the
dual ota would be my guess, because it does vary with bias current.

tomg wrote:

> I am not sure what I have done! But on my bench right now
> is a 2 stage (pole?) LP filter that sounds much better than
> most of the 2 or 4P LP group that has no caps! Actually
> it doesn't have much of anything.
>
> 1 - dual pnp
> 1 - dual ota
> 2 - pots
> 16 - resistors
>
> The upper range is especially clear and transparent almost
> sparkling but it roars down into to lower range. Notably
> when oscillating the sine is very symmetrical and uniform. Being
> stable to less than 1Hz. It really sounds terrific...No
> kidding!
>
> It's done with multiple feedback paths. Without me giving
> too much away, has anybody ever seen anything like this
> before?
>
> Tom
>

--
 -Jim
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