Jstickley I'm calling you out...............

[Blewbyou]

I have a question for you. I've got a Peavey Prowler tube amp, I purchased second hand because I love the tube overdrive sound. The problem is I don't really know much about tube amps. how do I know when a tube needs to be replaced? Is this something I can do myself I have heard tube amps can be dangerous to work on as they can hold voltage even after they are unplugged.
Blew

[Pekker_Head]

Quick tip, USE GLOVES when handling tubes. If the oils from your fingers get on them it could cause it to heat up mostly on that one side and cause a collapse.
I think the sound starts to fade, also they'll pickup radio signals (My solid state peavey did one time, scared me thought it was talking to me).
Though this seems to be good
http://www.athensmusician.net/archive/2004-04-23_tubes.php

[Jstickley]

Interesting question.

First and foremost. Tubes are NOT Capacitors, and will not retain power when unplugged. As was said before, you absolutly *CANNOT* touch the tube at anytime during its life. When you turn your amp on, and when it gets to temperature, if you have touched it.... Boom. Kinda a bad thing for your gear.

You will notice your amp sounding muddy, flat, just like crap. If this happens, your powertubes are likey to have headed south. If you get the muddyness, less gain, less sustain, fluctuating volume, that would indicate your preamp tubes.

When in doubt, change them out. Dying tubes can damage an amp.

When your removing them, use a VERY clean towel/microfiber cloth, pull the tubes straight out, dont twist, bend, in anyway. Once you get the tube out, take notice of the socket. Make sure its not burnt, if it is, you may have other issues. Take care of the tubes, you may need them in a emergency.

As for the new tubes, I would reccommend a matched pair. Since there is some other issues to deal with after replacing tubes, I would suggest getting a matched set of double what you need. Ie. if you have 3 power tubes, get a set of 6. This is not so much nessicary in the preamp tubes.

Once you replace the tubes, youll need to rebias the amp. This is the process of regulating the power to the new tubes, making the new tubes get the proper amount of power. Unfortunatly, this is somthing I wouldnt reccommend doing, for yourself, expecially if youve never done this before. It requires fishing around inside of the amp, while its on; and when its on and plugged in, tubes can be pretty deadly.

Unless that amp has had a hard life, or unless its relativly old, the tubes should be ok. I would still reccommend changing them at least every 2 years even with light use. Your amp will thank you for it ;)

Hope that helped

Jesse

[Blewbyou]

yes that helped a lot I knew not to touch the tubes but I didn't now about the need to rebias the amp I would have just swapped out the tubes and been done with it. I have had the amp proly 1.5-2 years and like I said it was second hand when I got it so I don't know how long the tubes have been ih it. I can't tell if the sound is muddy compared to fresh tubes as I've never had fresh tubes in it. For all I know the tubes could have been baffed when I got it although the amp sound pretty good to me. I'll order up some tubes and swap them out.
Thanks Blew