Recently on one of the boards that I frequent, someone mentioned a "universal" meter buffer circuit board made by someone in the LA area (if my memory is correct). However, my searches here failed to find that message. I am in need of at least six for some Sifam meters on a Neve 51 series desk. Thanks!
Hi
You only need a 'unity gain' amplifier although you may want to have a balanced input.
Kits by Velleman would be easily modifyable to do what you need.
Matt S