Tube compatability question

[riglehart]

Can you indescriminately swap between all of these without dire conscequences?
ECC81
ECC82
ECC83
12ax7
12au7
12at7

I've used 12ax7 in place of ECC82 and 12au7. My Jolida has two each 12at7 and 12ax7, and I've put four 12ax7 in it at the same time.

I have not ran into problems, but maybe beginners luck?

[RuSsMaN]

You can almost always go down in gain, going up isn't recommened, unless you are sure the specific circuit can handle it.

Gain factor 101 ->
http://thetubestore.com/gainfactor.html

Cheers,
Russ