Anybody care to surmise why the LDRs sound so good even with this THD. Is the THD mostly 2nd harmonic, is the THD cancelled in some way in use, does Georgehifi's theory of avoiding the capacitive behaviour of micro-contacts at high frequencies in pots hold?
Well, you want someone to seriously consider these LDRs, and do the required steps to put this stuff into its own place, correct?
Taking into account distortion performance of currently available parts, I don't consider LDRs worth further effort, but if you belive they do, or you have found someone else that does, then ask them to put one LDR into the signal path and to compare it against some known resistor. Characterization done this way will tell you most everything.
As for distortion, no it is not 2nd harmonic. Nor do I know why and how it may cancel. So here we go:
1. 2V RMS input, no attenuation, THD=0.02%
2. 2V RMS input, -20dB attenuation, THD=0.74%
3. 0.5V RMS input, -20dB attenuation, THD=0.007% (mistakenly I typed above "-12dB", it should read -20dB)
4. 0.5V RMS input, -40dB attenuation, THD=0.46%
Nice signature btw, and the thought that also runs through my head and is actual these days... As Cohen will be in Belgrade on 2 September.