What Happens When Preamp Tubes Need Replacing?

When preamp tubes need replacing, how do you know? What are the tell-tale signs sonically and otherwise?

Thanks in advance.

elf7311-10-2008 3:05am

newbee Details Discussions Posts This discussion Message User 4,795 posts 11-10-2008 at 03:49am Copy Comment URL Report Comment Edit Delete New noise, typically hiss crackle and pops, but also hum. The sneaky one is that gradually the tubes become rolled off and lose lusture. Pays to have an identical set about and every year or so plug them in and see if there is much, or any, difference. Good to do also because you will be cleaning the crud off the pins as the friction involved will scrape the pins.
karelfd Details Discussions Posts This discussion Message User 476 posts 11-10-2008 at 11:09am Copy Comment URL Report Comment Edit Delete Brilliant idea, thanks Newbee.
blindjim Details Discussions Posts This discussion Message User 3,092 posts 11-10-2008 at 12:57pm Copy Comment URL Report Comment Edit Delete I begin to sweat and fret and worry... about the expense of the new set.