Thanks for all your input so far. The Mullards I own I bought several years ago on Agon and are labled as 12AU7. I do think they sound pretty good. I am pretty sure though that they are not 1960s Blackburns or anything that old. Probably 1970s possibly 1980s. I have to admit I haven't dug them out to check to see that they don't say 4003 somewhere on them. Any other suggestions? Keep them coming! Once again something that is not overly rare or expensive would be preferred. Thanks again!
What are the best drop in subs for a 12AU7??
I am considering a Minimax preamp, but understand that they sound best with rolled 12AU7s. I have some Mullards which I would try first but have heard that there are even better choices of slightly different tubes. What are they and are they difficult to find? Thanks any help is appreciated.