How much do power tubes affect tone?

[lespaul6]

I was noticing a sloppy rumble after a palm mute in the key of A and C...weird, I thought the power tubes might be getting old so I decided to move them around to see if it would change the sound similar to a preamp tube roll. Maybe its all in my head but I noticed a slightly tighter feel and the low end cleaned up a bit. Are the tubes wearing out or do the pairs match more closely now balancing out the overall tone???

 

[Loudness250]

Going from brand to brand of power tubes , each brand has there own thing to an extent, but just moving your current tubes around, I don't know. I think maybe you got lucky and it solved your problem.

 

[guitarman967]

Depends how you moved them but in general the answer would be its probably a placebo effect because you know you changed something.
The sets do wear a bit differently in class A/B but id be damned if you could hear the difference by moving the sets from A → B and vice versa.

 

[Racerxrated]

With Marshalls I notice a difference between some brands. Winged Cs, Siemens and old Mullards just give a Marshall something a little "more" than a JJ or others. Not sure how to describe it..more definition, bite? The JJ EL34B does give a bit more low end but doesn't have that thing going on with the tubes I previously mentioned. YMMV..

 

[glip22]

They have a very big effect from tube type to type. They affect how the preamp signal is processed. The frequencies are affected by the power tubes. How dimensional the sound is also.

 

[lespaul6]

"They affect how the preamp signal is processed"

I suspected this might be the reason for the perceived change in tone.. I mixed the pairs not just swapped positions using the same pairs. It altered things... I think

thanks for the replies!

 

[splatter]

"They affect how the preamp signal is processed"

I suspected this might be the reason for the perceived change in tone.. I mixed the pairs not just swapped positions using the same pairs. It altered things... I think

thanks for the replies!

Different tubes operate at slightly different voltages . If you put a different brand of tube in and didn't bias the amp then its possiible that you changed what % the amp is biased at and that is why it sounds different .

 

[rupe]

It really depends on the preamp design and how far up you run the master volume (or volume on a non-master). Most high gain preamps color the tone to such a degree as to mitigate alot of the tonal coloration of different power tubes, especially at low volumes. The harder the power tubes are working, the more of their character they impart on your tone, especially with more simple amp designs like classic Fender, Marshall, Vox, etc.

 

[Racerxrated]

"They affect how the preamp signal is processed"

I suspected this might be the reason for the perceived change in tone.. I mixed the pairs not just swapped positions using the same pairs. It altered things... I think

thanks for the replies!

Different tubes operate at slightly different voltages . If you put a different brand of tube in and didn't bias the amp then its possiible that you changed what % the amp is biased at and that is why it sounds different .

This is true of course. But, to me there is a slight difference between EL34 brands. Not a large difference, but enough to choose certain brands over another. And I always check the bias when I put different tubes in. You'll only notice the difference when you push the amp louder ...IMO.

 

[guitarman967]

Maybe I misunderstood the question. Changing brands of power tubes will add a definite audible difference to the tone. Like a few here mentioned, the overall effect depends on a lot of factors. For high gain amps, I rarely bias past 60% of max dissapation of any power tube. I find that ample headroom for a high gain preamp is where the most balanced, clear tone is acheived and as a result the powertubes tone and color may not be to its full potential whereas in a older Marshall style circuit I prefer closer to 70%. You can hear the affect more in this scenario as the front end isnt as dominant in the overall tone. More of a 50/50 mix