[sdiy] Pitch detector Envelope follower!

[KD KD]

I need a quick fix for a pitch tracker and a envelope detector. Suggestions?

LM2907 seams to rippling alot yet linear, perhaps Harrys 3 way
solution are a lot better?
What are a decent evelope detector? The regular full-wave rectifier
with switch able times?

Something similar to MS 20 but way less components, it dont need to work 100%,
to about 80% would be OK, well do any analogue pitch tracker actually
work properly
do, i doubt.

KD