Germanium diodes with bias.

[catman]

G'day mate, well the loading effect of the diode does broaden the audio bandwidth slightly which is nice, feeding from a crystal set type of front end, and as to the bias, I just adjust it for the clearest audio quality, nothing too scientific.

Yes I have tried precision rectifiers based on op amps and I found them nothing particularly special, in all honesty. Regards, Felix (vk4fuq) aka catman.