MIXTEL/ Index

  Moving Coil Preamp  

I wanted to experience moving coil cartridges. I had heared that they had a clarity which moving magnets couldn't reach. First I bought a little mc transformer (I can't remember which now) which was good, but I have always liked the home-built approach.

This preamp appeared as a design in an electronics magazine. It uses two parallel power transistors as the input devices on each channel. This gives a large silicon area and, in theory anyway, lower noise.

As you can probably see from the above picture, the preamp is battery powered. This is fine for this application as the current drawn is extremely low and the batteries have a very long life - even if left switched on. I fitted an LED as indication and it draws more than the preamp even though it is run at the lowest current I could get a light at!

There is a very slight hiss from this unit but I don't find it objectionable even during quiet passages. There is definitely a sonic improvement over the transformer to my ear - there must be or I would have gone back to the original setup! Of course, when you build your own preamp you can set the cartridge loading to what you want so this may have helped.