Hard Med Soft Tubes. Whats that mean?

[stratman62]

I was looking at ordering some svetlana el34 tubes to try out in my roadster. I noticed they had that classified as hard med and soft.

Whats the difference and is one better than the other?

 

[stratman62]

I assume it has something to do with the current draw for the matched quads and where they are with respect to the tolerance/specification?

 

[joey_truelove]

It's a matter of when they distort at a given bias setting, how hard you need to push them to reach compression and following breakup.

Softer - Sooner
Harder - Later