gold lion 12ax7 , au7

Yes. I recently installed matched and balanced (section-matched) pairs of both types (Genalex re-issue ECC82's and ECC83's) in my Chinese-made Paxthon VTA-160 amplifier, in which I also have a matched octet of SED "Winged C" EL34's. I have been very pleased with the results.

Previously the small signal tubes were a pair of used 1960's vintage Telefunken 12AX7's (which measured and performed well until one of them developed a problem, which prompted my purchase of the Gold Lion's), and a pair of NOS 1950's RCA 5963's (which had never been used, and measured well, but with a possibly significant mismatch between the two triode sections in each tube).

In comparison, the most major differences were that the Gold Lion's eliminated some congestion I had been sensing on high volume peaks, and provided lower noise levels.

I purchased them from TheTubeStore.com, which optionally offers BOTH matching of tubes and matching of triode sections within each tube ("balancing"). The purchase worked out very conveniently, even though they are in Canada and I am in the USA.

I have no idea how they compare with the EH's.

Good luck!
-- Al

Its all perspective, and it drives me crazy sometimes, I have RCA cleartops , bought them from rogue, the test well but are bright and edgy in my system. I dont like them at all.

I've been wondering if a factor that might contribute to the variability of different people's assessments of dual triodes (aside from the obvious variables of systems, rooms, music, listening biases, etc.) is the degree to which the two sections of particular tubes may have differing characteristics, and variations in the degree to which different circuit designs may be sensitive to that.

As I mentioned above, in the case of the absolutely NOS 1957 RCA 5963's that I had been using, while the different tubes were well matched to each other, there were significant mismatches in transconductance between sections. Different circuit applications, obviously, will have differing sensitivities to that.

As you saw, Chris, I had raised that question in this thread, in a post dated 8-25-2010. Kirkus provided an excellent technical response, but there was little empirical feedback.

Best regards,
-- Al