Time To Replace Tubes?


I was wondering when do you guys decide to change your tubes?Are there any indications to listen for to know that you are at the end of your time with a set of tubes short of them blowing up on you?
I have a Wright 3.5 that has the 2a3,6sn7 and 5y3 rectifier tube in it.I was using a set of NOS Brimar's in the 6sn7 position.Recently i started thinking my mids were not there in my system and thought that my newly acquired modwright Sony 999ES may have been part of the problem.Well on a whim i swapped back in the stock EH6sn7's that came with the amp.I have very low hours on those tubes as i put the Brimars in not long after getting the Wright's.WEll my lordy the soundstage became huge and warm and just awesome just with swapping back in those EH's.
Maybe they just work better synergistically with the Modwright player i don't know.Maybe the Brimars are still fine but sounded lean with this player?
But back to my original thought on this is there something you can audibly listen for when you know your tubes are going?
Now i wonder if replacing the 2a3 or the 5y3 will bring even more sonic gains?It sounds incredibly better now just with that 6sn7 swap.I was looking into new speaker wire and possibly a tube preamp and here all i really needed to get those mid guts were to put back in those EH's.I'm loving that too cause they are a heck of alot cheaper then the NOS route.
What a pleasant surprise!! : )
seekburk
Hey Stew - How do you like the Mono 10's you got? Are they working out for you in your system?

Marco
Seekburk,

I own a Wright WLA12A preamp, which also uses 6SN7s. When my stock EHs got noisy, I wrote George for recommendations and got this response:

Dear Dave,

NOS are almost always a better choice for 6SN7's but the availability is getting harder to find these at a good price. My favorites are the mid 50's to late 60's production angled plate 6SN7GTA or GTB, RCA are also nice, the best are American made Raytheon, Westinghouse or Tungsol,good luck. The EH's are robust and fairly reliable as well, but a bit forward.

Best,

George

Taking his advice, I found some reasonably priced Sylvanias from the 60s, and they've been a major improvement, much smoother highs than the EHs. I tried some Sovteks and they were pretty bad in my amp, although many mfrs seem to use them as their OEM tube. I also tried some NOS GEs from the 70s that I got for free, and while they were slightly better than the EHs sonically, 2 out of the 4 were noisy. I haven't had the inclination to try any of the $100/pair 6SN7s, as I don't think my pretty basic preamp and system warrants them.

All in all, I'd rate the EHs pretty high considering their price and availability. You can improve on their sound with older tubes, but unless you're lucky enough to get them cheaply like I did, you'd probably have to spend a lot of money for the improvement.
Thanks once again for the replies folks!!
Yeah i think i will have to rely on my own ears jax2 rather then to buy a $500 tube tester that i really don't know anything about.That money can buy alot of affordable tubes.
Smeyers, thanks for your input on those 2a3's.I think i will have to check out those EH2a3 gold's myself now after reading your results.I also would be interested to see how you find the Sophias after they break in so keep us posted if you would.
Armstrod, thanks for your reply as well about those tubes.I will keep my eyes open for some of those tubes but right now, like you said, the EH is a good bang for the buck tube.It did actually make things a bit more forward and i think that was a welcome thing for me in my system.It filled out the mids nicely.One thing i have noticed since i put that tube in however is a slight ringing in my ears after a long listening session.I don't know if that is from that tube or from wanting to play my stereo louder now.I never play that loud but i am noticing a slight din in my ears at night in bed the last few days.Weird and i want to monitor that for sure.Wonder if that tube could be imparting any artifacts that could be causing that?I don't know but it is a phenomenon i don't want to have keep repeating.Strange though too as like i said i like the sound of this tube.Well at least i like how everything has gelled lateley which i think we all know is such a welcomed moment to savor in space and time! ; )
A couple of things:

I'd agree that the EH tubes are more forward sounding. I actually like this, since it makes certain instruments (vocals in particular) feel as though they are practically in your lap! Some people prefer a more laid back presentation though.

The Sophias are starting to get better. The bit of fuzziness and lack of soundstage depth is dissapating. I doubt however even after fully broken in that they will be as forward as the EH tubes. David at Sophia mentioned that the 'Princess' tubes do take a long time to break in.

You may want to invest $50 in a Sound Level Meter. This is an easy way to determine how 'loud' your music is playing to see if loudness might be causing the ringing in your ears. Radio Shack sells both digital and analog versions.

- Stew
Seekburk,

See my posting in this thread:

http://forum.audiogon.com/cgi-bin/fr.pl?aamps&1136483835&openfrom&18&4#18

I strongly recommend dampers on at least your 6SN7s, if not all your tubes. They make a world of difference on my preamp, including getting rid of the ringing you're hearing.