I have an Aphex 107 manufactured in 1997 with a Phillips 12AT7 tube in it (the original). Any benefit swapping this tube out for another? If so, to what Brand and Type of tube?

Hi,
I've an old VTDB-2B Tube Direct Box and I want to replace the tubes.
I sent an email to Demeter, but no reply...
Is there someone who can say me what tubes I must buy to replace it?
Thanks

i've been thinking about saving myself some money by replacing the stock 12AX7 tube inside my $80 preamp with a better tube. (i think i ran across the bnb tubes site in one of these forums).

is this something slightly common? would it be worth it? would i get myself a more pleasing sound or a bad electrical shock?

Hi.

So I own a Mesa / Boogie Dual Rectifier Tremoverb.

Is it possible to replace the 6L6 valves with 6550 ones? Id like to be sure before I do so I dont damage the head.