when to replace tubes in preamp?

[JP hardboiled]

Anybody have experience or have a preamp w/ a tube. I have a dbx 376. I bought it used and I'm not sure if the tubes need to be change. How often does this need to be done and how can you tell if it needs to be changed? It sounds ok to me, but not as full as it could be. You can check out the vocals on my myspace site. They were all done w/ the dbx 376. Thanks for any advice.

 

[Formant024]

well, if they dont light up/warm up they'll probably de dead, same for loss of sound in one the channels as it interrupts the cirquitry of the signal path.

and with all respect.. rtfm!

 

[Chrono]

i heard every 6 months depending on usage.. I heard it's important to change it before it fuses to the unit and is unremovable. I was researching teh Presounous Pretube when I came across this information. Gl Hb

 

[Jenre]

Depends from unit to unit. Some only need to be changed every 10 years or so. I guess if they dont light up they need changing? I'm no expert though.

Different tubes will give different qualities so even if yours dont need changing some new ones might still improve the sound. Check them out before you buy them, though.