Audio Systems: Mullard, curve tracer, tecktronix

Question
Hi,
I'm curious about the Mullard re-issue tubes from New Sensor Corp.  You can get a matched pair of EL34's for about 40 dollars. The original NOS Mullards, though, go for up to 400 dollars for a matched pair.  how good are the re-issues compared to the NOS?
thanks
-Jim

Answer
They look ok to me.  How could you go wrong?  If they bloob or fail in any way you are not out much.

If you have access to a curve tracer (by Tecktronix or other instrument manufacturer) you can trace out their performance characteristics and see how they look.

The reason the original Mullards are so expensive it tight supply.  And, they did a good job making them.

But, for sound quality, as long as they follow the same curves and have the same cathode and plate construction they will be alright.  If they don't last as long you may have to replace them, but at this price, so what; maybe buy two pair of them as a backup!

And, they always were a good sounding tube.

Cleggsan

PS: By the way, if you are putting them into an already existing amp, and if they bias up exactly the same point or very close to it, that is a good sign. If they bias way off the mark, then you can worry a little about their authenticiy - but they may still work, just the same.