here is the ''dirty'' version... still no biassing,
But now it IS biased..!!

(via diode - 22k - 22k ..)
P.S.
Iain, I
think you have to present integraded circuits..
(not all forum members are able to readily implement a "main idea" circuit into a working effect..)
BTW, you could obtain half wave rectification without amp_1 out diode..
(just maintain GND bias and single supply..)
