Funny how things go in three's. With "the wife" having taken to her sick bed a couple of weeks ago and in between my impersonating Basil Fawlty and chasing around like a lunatic catering for her every need, I found time to tinker with some abandoned DIY stuff that had gone a bit funny sometime ago.

One of these Pre's was a Lightspeed using LDRs (Light Dependant Resistors). I am probably teaching to the perverted so apologies if I appear be sucking eggs.

If anyone was a member of Diyaudio about 8 years ago there started a looooooong thread urging everyone to build one of these as they were "revolutionary", the pot is used as a voltage source and there are no moving parts in the signal chain. The parts count was very low so I built a couple for myself and some for friends. The one in front of me last week was a "proper" offering, by "proper" I mean it was built with a PCB not P2P and has matched LDRs. However, it didn't sound right. A bit of tinkering and it didn't take much to bring it on song.

An LDR Pre is a passive unit, but IMO it sounds so much more like an active pre. If you haven't tried one, you ought to give one a go. if you can use a soldering iron and follow a simple schematic, you can build one for about £20.