Hi guys. What tonal changes normally occur from deteriorating power tubes? I bought my first tube amp last month, along with fresh set of power tubes. I've been playing it for 1-2 hours/day at very low volume, I notice the sound become more shrill/harsh lately, I wonder if it's due to power tubes or something else.
Power tube deterioration
- Thread starter Dr.J4ckal
- Start date
Re: Power tube deterioration
To be honest with you...it is pointless to come up with some scheme to judge tubes.
Power Tubes (assuming they are functioning properly) tend to "wear out" slowly...loose punch, definition, and low end. But who cares.? You should always have spares. So you swap in a new set and see if there is a big change.
No need to sit there and try to listen for more mids, more responsiveness, etc etc. If the improvement is obvious, then the "old" tubes were due for replacement. If not, put the old tubes back in and keep playing them.
Same with noise and microphonics. No need to ask...Just change the tubes and see what you hear and feel.
Keep in mind that tubes Can and Do go bad at any time...always have spares.
best
To be honest with you...it is pointless to come up with some scheme to judge tubes.
Power Tubes (assuming they are functioning properly) tend to "wear out" slowly...loose punch, definition, and low end. But who cares.? You should always have spares. So you swap in a new set and see if there is a big change.
No need to sit there and try to listen for more mids, more responsiveness, etc etc. If the improvement is obvious, then the "old" tubes were due for replacement. If not, put the old tubes back in and keep playing them.
Same with noise and microphonics. No need to ask...Just change the tubes and see what you hear and feel.
Keep in mind that tubes Can and Do go bad at any time...always have spares.
best
koshikas
New member
Re: Power tube deterioration
what is the amp in question, what are the power tubes featured now, is the circuitry stock, did u have the new set of tubes thrown in for a used amp. was it biased? u ll need to give us more information for this to go any distance man.
if is not fixed bias swapping out power tubes all by urself for a new set is not that easy.
what is the amp in question, what are the power tubes featured now, is the circuitry stock, did u have the new set of tubes thrown in for a used amp. was it biased? u ll need to give us more information for this to go any distance man.
if is not fixed bias swapping out power tubes all by urself for a new set is not that easy.
El Supremo
New member
Re: Power tube deterioration
Bias could also be drifting lower. Check it with a multimeter and adjust if necessary.
If you play at low volume 2 hrs day, a good set of tubes will last a year at least without loosing significant clarity, punch, etc.
Bias could also be drifting lower. Check it with a multimeter and adjust if necessary.
If you play at low volume 2 hrs day, a good set of tubes will last a year at least without loosing significant clarity, punch, etc.
Lake Placid Blues
New member
Re: Power tube deterioration
Yeah harsher sound is likely bias drift. It's really the tubes drifting away from how they were biased as they burn in. This may or may not be something you can check your self, depending on the amp. We need more info.
Yeah harsher sound is likely bias drift. It's really the tubes drifting away from how they were biased as they burn in. This may or may not be something you can check your self, depending on the amp. We need more info.
Edgecrusher
New member
Re: Power tube deterioration
Or hearing fatigue... a couple hours a day at low volume is very little tube wear really.
Or hearing fatigue... a couple hours a day at low volume is very little tube wear really.
Re: Power tube deterioration
Hi guys, thanks for the replies. The amp is a mesa mark iii simul class combo, so it's a fixed bias. It's old (from 1989), I plan to have a cap job and other maintenance done in june or july.
I found that it sounds better in 15 watt mode (outer pair only) so I suspect maybe one of the inner tubes is going bad. I use 4 mesa 6l6. I'll try tube rolling tonight and see if it's really from the tubes.
Hi guys, thanks for the replies. The amp is a mesa mark iii simul class combo, so it's a fixed bias. It's old (from 1989), I plan to have a cap job and other maintenance done in june or july.
I found that it sounds better in 15 watt mode (outer pair only) so I suspect maybe one of the inner tubes is going bad. I use 4 mesa 6l6. I'll try tube rolling tonight and see if it's really from the tubes.
El Supremo
New member
Re: Power tube deterioration
I've had a variable bias installed in my Mesa. Saves cash on tubes as your not limited to Mesa's offering. Highly recommended.
I've had a variable bias installed in my Mesa. Saves cash on tubes as your not limited to Mesa's offering. Highly recommended.