Tube Amps / Music Electronics
For current discussions, please visit Music Electronics Forum. New: view Recent Searches.
New: visit Schematic Hell!
The sunn still shines online!

Listen to great tunes streaming live right now!

ampage archive

Vintage threads from the first ten years

Search for:  Mode:  

How do I know if my tubes need to be replaced?

8/6/2004 7:08 PM
How do I know if my tubes need to be replaced?
Short of a failure, how am I supposed to know if I need to replace my power tubes? Are they like guitar strings where their tonal quality degrades, but the otherwise, operate fine.  
8/6/2004 11:27 PM
Wild Bill

Dan, you can put them in a tube tester or better yet substitute new ones but other than that things aren't really obvious.  
Usually the power tubes lose emmision and deliver less and less power. Preamp tubes usually go till they die but sometimes they will act so flaky you know something's wrong.  
So the short answer is that if the amp seems not to be as loud as it should it's time to consider the output tubes. If the tone is there and as loud as you expect then don't worry about it.  
---Wild Bill
Book Of The Day The Ultimate Tone, Volume III by Kevin O'Connor
Have you ever wondered if there is a better way to build a Bassman, Champ, Plexi, an 800, AC-30, Bulldog or Portaflex? Or you wanted to build an SVT with off-the-shelf parts? How about a master-volume amp that doesn’t change tone with the master setting? Everything you need to know is right here, including: proper grounding techniques, wiring methods, and mechanical considerations. Eighteen chapters cover the “iconic” amps everyone knows and loves, with schematics and layouts for each, along with the technical history of the product. Eyelet-board and chassis-mounted tube socket construction is used throughout, for easy servicing and modding. TUT3 is very accessible even if you cannot fully read a schematic and is a "must have" if you are going to build an amp for your self.

Note: The Ampage Archive is an Amazon Associate site. A small commission is paid to the site owner on any qualified purchase made after clicking an associate link such as the one above.
8/6/2004 11:28 PM

That is exactly right. Like strings, they will continue to function after their tone has faded away.  
If the amp has lost its sparkle, sounds a little dull, maybe not quite as strong, you ought to look for new tubes.
   Page 1 of 1