Originally Posted by MikeW
further listening, I really don't like the JJ tube.
This is no surprise to me. I couldn't understand why anyone liked them. Considering how inexpensive NOS 12AU7's are, and how much better they are than current production tubes like the JJ...
Originally Posted by lennybrisco
I just bought an EF1. Already own a DOGE 6210 which uses 12AX7's and have a small collection of tubes.
Maybe this is stupid, but... can I swap in my 12AX7's for the stock 12AU7? Or do they have too much gain? Not sure how compatible these two types are in hi-fi amps and don't want to wreck the new guy!
I wouldn't. The 12AU7 and 12AX7 are somewhat similar, and there is a possibility that it might function without causing a serious problem, but the odds of it working fine and sounding good are slim. Using a 12AX7 in a circuit designed for a 12AU7 is asking for trouble and unlikely to provide any real benefit.
The good news is the 12AU7 isn't that expensive a tube.