#1
So yesterday I changed my preamp tubes from 4 12AX7s to 2 12AX7s in the v1 and v3 and 2 12AT7s in the v2 and v4 positions to reduce some gain. That definitely worked, but since the drop of gain, I've noticed that my sound is pretty thin. I don't know if I'm overthinking it, but I was wondering if I need to change my power tubes.

My amp is a Peavey Triple X and it was made in 2005, I don't think the tubes have been changed since all the tubes are the same as the specs, then again someone could have changed them. My tubes have a dark orange glow to them when they heat up. I was wondering if there are any other signs of a bad or old power tube.

EDIT***
My powertubes have a bluish glow around the edges, along with the orange glow. I swapped the 12AT7 in the v2 position with the 12AX7 and it returned some low end. Im gonna record both to see if my mind is just playing tricks on me.
Last edited by Sir Stoney at Jul 18, 2014,
#2
I think the preamp tubes are fine. The recorded tone isnt much different. The new tube is louder, thats about it. I do believe my bluish power tubes are bad though.

I put the AT7s in the v1 and v3 positions and I'm leaving it. It took off some gain and some high end. At least to me, otherwise this is a tube conspiracy. I apparently didn't put a tube in all the way because as soon as I took it off standby hell was raining above. Hopefully that's not why that bit of high end was cut. I Like it though.
Last edited by Sir Stoney at Jul 18, 2014,
#3
I'd imagine the change is from the preamp swap, not power tubes. Try swapping the 12AT7s around to see if they work better in other positions.
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#4
Blue power tubes is normal, however it never hurts to have some spares, I'd buy a set just to be safe.
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#5
Quote by dementiacaptain
Blue power tubes is normal, however it never hurts to have some spares, I'd buy a set just to be safe.


x2. If you replace your power tubes now you have spares/good tubes to test. If you wait until they blow you won't have good ones.

Simple.

And some preamp tubes can leave an amp very thin sounding, location of said tubes makes a huge impact as well, typically V1 has the highest impact on an amp.
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#7
Put a good 12AU7 in v1, leave the rest as AX's. You'll accomplish the same thing and end up with better overall results, at least IMO.
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#8
for a slight drop in gain i prefer the 5751 tube.
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#9
Quote by Arby911
Put a good 12AU7 in v1, leave the rest as AX's. You'll accomplish the same thing and end up with better overall results, at least IMO.


wow, that is a pretty low gain tube. i have lost quite a bit of volume using an AU7. i am interested in hearing the results.
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#10
Quote by gumbilicious
wow, that is a pretty low gain tube. i have lost quite a bit of volume using an AU7. i am interested in hearing the results.



I've done it with several amps that are really gainy to give me better clean headroom. I've noted no ill effects because usually these amps have way more gain than is "usable" anyway.
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#11
Quote by Arby911
I've done it with several amps that are really gainy to give me better clean headroom. I've noted no ill effects because usually these amps have way more gain than is "usable" anyway.


how much volume loss have you noticed? that was my big problem with using 12au7's, but i have never used one in V1 before either.
punk isn't dead, it's always smelled that way.

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#12
Quote by gumbilicious
how much volume loss have you noticed? that was my big problem with using 12au7's, but i have never used one in V1 before either.


Honestly I never noted a significant drop, probably because I went in knowing I would have to change settings so I never really took it into account. It may have been there, I just didn't pay any attention.

I know that's not helpful, sorry!
“Ignorance more frequently begets confidence than does knowledge.”
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#13
Quote by Arby911
Honestly I never noted a significant drop, probably because I went in knowing I would have to change settings so I never really took it into account. It may have been there, I just didn't pay any attention.

I know that's not helpful, sorry!


it is helpful actually, cuz where i plugged them in at there was a quite noticeable difference.

if i was really on point, i'd just plug one of my 12au7's into a V1 and observed the difference for myself
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