I'm still doin' pretty good with the stock EH 6922s in my Premier 17. I don't know if they've ever been replaced as I'm the second owner of this fine pre. I do want to get some GL 6922s in to try those out, or maybe some Ediswans.

The CT-5 hasn't been a problem, but I think I'm just now getting somewhere around the 1000 hr mark, and those 6H30/6N30s were specifically designed to be extremely durable, so no issues there.

I have confirmed with CJ that there was a defective series of tube from EH. It appears the 2010 series of 6922 have had a high failure rate with many going noisy only after a few hundred hours.
I have seen this in the ET3 as well as the ET5. In both cases putting in another tube (either JJ 6922 or even better Gold Lion 6922) took care of the problem.
As a general rule, avoid EH 6922 that have the 2010 date on them.

Tubes is the ET5 should last 3-5 year without a problem.

Great, that's when I bought a backup pair :(

Most of my spare ones 411are 07 09. Replacement gat two are 09 09

I am sure EH had qality issues in other series tubes as well. Try a Gold Lion and you should have no problems for years to come. Although its the same company the quality control on the GL's is much better.

I don't know if it's my bad luck with tubes, the ET-5 being somewhat tough on tubes or what. :tears:

In the last few days... the system has been moving to sounding "2D" vs that lush magical almost "3D" sound stage. bass seemed a bit anemic and overall just less pleasing.

Just for the heck of it on a whim today, I popped the Ediswan 6922 back in. well right off the deep end was back..and I was back to "seeing the sound in 3D"

So then I do my standard micro phonics tube test on the Ediswan. A simple light touch of the tube in question. In this case it causes a monstrous sound in both speakers. This tube has become one of the best microphones I've ever seen. I know some of this is normal with any tube...and some tubes I can slap pretty good with no micro phonics whatsoever.

So, at this point, although the EAT 6922 is dead quiet and seems to "work", and the Ediswan works wonderfully, but is micro phonic as all get out. (oh and yea, this is of course a "Platinum" version of the Ediswan.) I'm keeping it in for now and ordering another. I'm not sure what I'll do with the EAT. :puzzled-2: My first EAT went way noisy, this one started off sounding wonderful, it still works, but sounds terrible.

Happy Holidays to everyone!!

Well... My Gat sounded a bit flat so I gave the Holland Mullards I put in a few months ago a little tap. On was very noisy and the other just a little. So in went my old EH6922s. One's a little microphonic the other is fine but the sound is okay again. Think this NOS thing is always a gamble. Maybe better to stick with something new and tested. Guess I'll get Ed to send me a couple of new ones tomorrow.

Happy new year to everyone! :roots::wine::newyears:

Bob

my GAT is since a few days equipped with EAT 6922 selected.....it is very probably the end of my adventures on NOS territory,they are absolutely magnificent in all the departments....more to come but but by far they are the best 6922 that I listened with my GAT, I tried Tesla, EH, GL, JJ, Mullard Holland.... remain to verify their reliability in the time
btw I have just had a failure on a new set of NOS Mullard in the 'ignition' and I have fear the worst for my amplifier....

Hoping the result is not "the worst," Philippe.

Happy new year back to you, Bob.

While I've been tempted from time to time to tube-roll in my PR17, I've had such good luck reliability-and-longevity-wise with first the original-equipment Sovteks and more recently EH's that I've decided to leave well enough alone. While that means foregoing a possible bump in performance, I tend to sleep better at night. :D