Pass though 6-stage [lop~ 8000] to try to eliminate
(attached).

Set the Q to about 3.

Now keep the frequency of the oscillator and the filter cutoff freq

below 100 hz.

Try [bp~] then try [vcf~].

No matter what the setting of either (as long as they are both below 100 hz),

I get I get a strong artifact at 4k, another at 12k, another at 17k.

This has been bugging me for months.

I can't figure it out.

I thought it was super-Nyquist foldover,

but the [lop~] didn't eliminate it,
and it does not seem dependent on the frequency of the oscillator.

Any ideas?

Sample rate=44100 hz. Delay= 80 ms. Blocksize=64.
Pd 0.46.7 on Windows 7.