Every episode of Bill Ruppert's Effectology - a series where he creates classic sounds using effects pedals in a modular synth style manner - is fascinating.
The latest episode, though, is especially fun as Ruppert recreates Delia Derbyshire's vintage electronic arrangement of the original Dr. Who theme, using just a guitar and Electro-Harmonix effects pedals.
No keyboards, samplers or midi pickups were used.
Details on Ruppert's settings are available at the EHX forum.
A variable width bandpass filter and a voltage controlled mixer