Valves need changing?

[Pman]

I have a 5150 2x12 combo that i bought in 2006 on eBay.

The valves had recently been changed and the original owner bought it in 1994 apparently.

It sounded great then, but after moving away for a few years it remained fairly unused.

Recently starting since last year I have tried a few recordings with it and the results have been fairly lackluster compared to what I used to get with it.

I was wondering perhaps the valves are wearing thin and may need replacing

Here are two recent recordings with it:


from the http://www.ultimatemetal.com/forum/practice-room/569814-definitive-rose-sharyn-di-backing.html
Zero post processing on these guitars.

and re-recording the guitars on a friends thrash song, just for fun
https://dl.dropboxusercontent.com/u/8740721/kotkgtr3.mp3

Clearly I have no general knowledge regarding tube amps and valves but to me, it seems like i'm not picking up much beyond 6kHz.

I'd appreciate any opinions and advice, cheers!

 

[bryan_kilco]

I'm no expert here, but usually you can hear your amp making weird pops and scratchy type sounds when tubes are failing (power tubes, at least).

You may want to take it to a tech. Possible leaky caps if it's almost 20 years old, maybe?