how do you know when tubes need changed

[60 second crush]

i have a marshall dsl 2000 100 watt head how do you know when you need new tubes or when the amp needs re biaes?

[Enzo]

Oh you could check the bias once in a while. But mostly we set it when they are new, and pretty much let it be.

If the tubes are showing signs of failing - pops and crackles, flashing, or other things - then get rid of them NOW before they damage something.

Otherwise, you know when to change them the same way you know when to change strings - when the tone has gone away. They will still function long after their tone has gone lifeless.

I'm in Lansing, where are you?

[60 second crush]

Oh you could check the bias once in a while. But mostly we set it when they are new, and pretty much let it be.

If the tubes are showing signs of failing - pops and crackles, flashing, or other things - then get rid of them NOW before they damage something.

Otherwise, you know when to change them the same way you know when to change strings - when the tone has gone away. They will still function long after their tone has gone lifeless.

I'm in Lansing, where are you?

thanks alot i live in monroe

[bob p]

If the tubes are showing signs of failing - pops and crackles, flashing, or other things - then get rid of them NOW before they damage something.

Replace them NOW!? Now that is good advice.

I remember the first time I saw a flashing tube. I had dumpster dived an old Silvertone Twin Twelve head, and it had two RCA Blackplate 6L6 in it. I was in hog heaven. I even thought it was cool to see the tubes flash blue every time that I strummed a chord. The Blackplates didn't last long. Sigh. The good news is that the tube didn't take anything with it when it started arcing.

[60 second crush]

Replace them NOW!? Now that is good advice.

I remember the first time I saw a flashing tube. I had dumpster dived an old Silvertone Twin Twelve head, and it had two RCA Blackplate 6L6 in it. I was in hog heaven. I even thought it was cool to see the tubes flash blue every time that I strummed a chord. The Blackplates didn't last long. Sigh. The good news is that the tube didn't take anything with it when it started arcing.

do i need to replace all the tubes i take i do???
thanks for the replies

[bob p]

do i need to replace all the tubes i take i do???

i would have guessed you're from the UP.

[Enzo]

The four large power tubes wear out just doing their jobs. That is normal, just like it is normal for your car tires to wear out after so long. SO if it is time to replace tubes, replace the set of four power tubes. The small tubes - 12AX7 type - don't really wear out. They can last for many years. Some do fail, of course, but it is not really necessary to replace the small ones when the large ones go. Unless of course one is bad, in which case replace the bad one and leave the rest.