When to replace pre-amp tube?

Hi...answer is a little bit "it depends". What kind of tube? you can usually google the typical time of wear...3,000 hours for some,,,20,000hours for the longest. Or ask your manufacturer/dealer. Then do the math...how many hours have you played them? Then do the listening test...you tend to hear a slight fuzzing over of your mid to uppers, or the power just does not seem to be there...not as solid imaging. And of course, when you replace tube, it is instantly back. good luck

Thanks. I believe it's the RCA nuvistor 6cw4 tube.

When you get curious as to how another brand or type will sound in your gear.

If you think its been used for a long time and your not having any problems,thats the time to replace the tube..Much easier ( and less costly ) to just spend the money now and be worry free for a couple more years.......

When marketing the amplifier, as far as I recall, MF stated they were good for 100,000 hours and that they would "reserve" a replacement tube set for every unit produced.

That was then and I don't know what the now position is.

IIRC, the nuvistor tubes are very long lasting. Yep, here it is, S'phile review of Nuvistor amp says "Typical tube life expectancy is about 100,000 hours, and the failure rate, with almost 1500 Nu-Vista products now in the field, is "about 0.1%." So don't worry. " lets see, 100k hrs = 24/7 for 11.5 yrs.

About once a week.

Swampwalker

that's a simple enough math :) thanks

Done!!! Thuaile, i think you are in very good shape. good luck and enjoy!

Thanks for fixing it :)

Anyone with tube equipment should keep spare tubes on hand because you never know when you can have a tube failure. If you think your tubes are getting worn you can try a new tube and see if you hear an improvement. If you don't hear an improvement your tubes are ok.

NOS tubes last much longer than new tubes. This is something else to factor in when considering cost.

08-28-11: Rrog
Anyone with tube equipment should keep spare tubes on hand because you never know when you can have a tube failure. If you think your tubes are getting worn you can try a new tube and see if you hear an improvement. If you don't hear an improvement your tubes are ok.
Rrog (Answers | This Thread)

Rrog, I agree with you. Now tell me where I can find another new MP of 60's Siemens Cca for my preamp at a REASONABLE cost? :-)