DIY AUDIO LDR kit projects

I'm an ancient DIYer who has been messing with valve amplifiers and audio stuff since the 1960's when stereo didn't exist, transistors weren't invented and LP records were just starting to appear. Brands like Leak, Wharfedale, Ortofon and Quad were just appearing.

Technology and audio reproduction techniques have evolved so much over the last 5 years that it is possible to build your own equipment that rivals the best available for a few hundred dollars .

My policy is not to build my own speakers any more. The problem being that I was always tweaking, which meant that changes to other components like cables were negated.

My listening space is compact so I have settled for a pair of KEF LS50's. Their speed and lack of any cabinet colouration has given me a 'standard' that allows the changes in any components to be emphatic. I also use a 6 inch REL SubZero positioned and set up using Room Eq Wizard. Sub/LS50 balance is critical and REW let me optimise levels for a smooth crossover.

I have also built a Holton Precision power amp which to my ears absolutely uncoloured and capable of accurately reproducing any signal without stress. LS50's and Holton are a match made in heaven.

I was a complete cynic and didn't believe that interconnect cable, RCA connectors, active and passive preamps could affect sound quality so dramatically. Now I'll try almost anything, no matter how strange. *My colourful Cat5 braided speaker cable project sounded awful on my system but others seem to love them.  You'll never know till you give it a go.

My introduction to LDR Optocoupled passive preamps was a DIY Lightspeed from a public domain circuit. The sound was a revelation. Curiosity made me lash out and order a Stereo Coffee kit, just to compare it with the DIY Lightspeed. The Stereo Coffee had 3 channels, much tighter bass, the volume could be zeroed and the sound was more 'adult' and involving. I also bought a Clone Note kit that uses a switched level /shunt control resistors instead of a potentiometer for incredibly repeatable balance. * The production Lightspeed has a large following around the world but my experience was with the public domain DIY version.

LDR Preamps cost less than $200 and have been a revelation to me and have totally change the way I enjoy music. I can't believe they aren't more popular.

What is LDR sound to me?

When I first heard an LDR preamp, the very first note stopped me in my tracks and I listened for hours enveloped in a three dimensional world of beautiful music, experiencing the character of artist's voices and instruments seemingly in the room, without any fatigue or feeling that the music was too loud. I was hooked!

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