My current line stage is 1626 in differential pair with a CCS under it.
I like this quite a bit but am keen to go one step higher in terms of
sound. I plan to order some DHTs but since I need two matched pairs I
want to get a good idea of what to order first. I'd like to keep the mu
and plate impedence (Ra) lowish in case I go PP with an output
transformer.
Seems like 31, 46 (in triode) and 71A are suitable
12A and 26 and 843 (IDHT) are close
01A and 30 is just possible (1LE3 is getting too high mu/Ra)
I'd like help choosing from you guys that have heard these or used
them. By all means suggest any others (though not stupidly expensive -
I need a few)
I'd also like some idea of which are low on hum and which require
special measures so I know what to expect. Bear in mind it's a balanced
line stage, if that helps with the hum at all.
Thanks!!! Andy