Time To Replace Tubes?

In your case you don't need anyone to tell you it's time to change those tubes, or that one is better than the other; you figured it out on your own with your own ears. I don't think NOS is always necessarily better than current production. There's plenty of fine late production tubes out there that sound swell...even better than NOS in some cases, as you've found out. That's not to say there may not be an NOS 6sn7 that bests the EH you like...just that the Brimar's you have don't sound as good to you (they may sound good to someone else though...stranger things have happened). The other way to tell if and when tubes need replacing is to have them tested by someone with a tube tester, or buy one yourself and test them. Obvious signs fo failing tubes are noises like pops and clicks and or rushing sounds. Familiarize yourself with typical tube-life you may expect from the various types you use. I did like the late production Sovtek 2a3 tubes in the Wright 3.5's. I think that's the one tube Sovtek actually does a good job with (haven't liked any of their other tubes I've heard). I hear the NOS RCA's do a good job for 2A3's but you will have to pay some large coin for a good pair. Some company is also making some 300B's that run at 2.5 volts to be a drop-in replacement for a 2A3. You should probably check with George if you want to try that. No experience there. I think swapping any of the tubes has the potential to alter the sound. Probably the least potential would be in the 5y3 rectifier, not to say that it wouldn't have any potential. My experience with those amps tell me that the other two tubes have more impact. YMMV as always.

Marco

Thanks Marco-
Ya know the Brimars 6sn7's(in the Wright 3.5's) sounded better when using my other players(Quad 99cdp,Jolida 100 level 1 mod,and Music Hall CD25 level 2 mod)but since receiving the Modwright 999ES they sounded to thin for my tastes but maybe they were just ready to be moved out.Whatever the case i am loving life again with the EH 6sn7's again in the Wright's.I run passive using EVS nude attenuators and it was really getting to the point where i was concidering a tube preamp to get the lushness back again.Well it is back and i am really happy with the sound right now.So i guess there is a lesson to be learned here that might help some other people.When you think that you may need an equipment upgrade or cable upgrade just remember to check those tubes first or swap them out.Oh and get the best source you can possibly afford i have learned as well as this Modwright has taken the performance to the next level for me and i will probably be posting my other players for sale down the line when i get around to it.Those players were/are really nice players too but this one just presents things better to my ears but of course it was more then double what i paid for any of the others.Not an add for Modwright just my experience citizens. ; )
I think i remember reading that there are gold EH 6sn7's now but i may be wrong.Does anyone have any knowledge or experience with them and how they sound compared to the standard EH 6sn7's if in fact the golds do exist?
thanks!

TJ Full Music 2A3's are much nicer than the EHGolds which aren't bad at all.

There are a few amps that are manufactured with a digital clock built in so you can keep track of "on time" and have some approximate idea of when the tubes might need attention (some ARC amps for one). It is also interesting just to have some idea of the amount of time you spend listening.

You can add such a timer in several ways, the simplest of which is to plug one into a switched outlet on the preamp (if you have one). More challenging is to design a timer interface that runs off the 12v trigger. Or you can just start and stop a timer manually (of course it is easy to forget).

My timer shows about 10 hours per week on the average right now. At that rate a set of 6550 amp output tubes should last at least 2 years. However, it all depends on the amp, the tubes, the amount of use, the level of play and some luck etc.

since tube amps are symmetrical, whenever there's something going on soundwise which is tube-related, you can do things like swap out tubes like you did or, if the funny business is in one channel, switch the left and right channel tubes one by one to isolate the problem. this is especially true for input tubes like your 6sn7s or preamp tubes. bad tubes often make nasty sounds when you tap on them. I don't think it's a good idea to get into the mind-set of 'there's something wrong with my tubes that I can't actually hear'.
assuming you're biasing your tubes, that will tell you how your power tubes are doing: if they're having trouble holding a bias, you may have a bad one. and eventually they just fail, often in very unsubtle ways with loud noises.