#1
Okay, so I know that power tubes have to be replaced with the same model (i.e. EL34's need to be replaced with EL34's and so on).

Is the same true with preamp tubes? I thought I read somewhere that it wasn't.

The amp in question is a '74 Fender Bassman 50. It has three 7025's and a 12AT7 for a phase inverter.

I know that 7025 is the industry name for 12AX7's so I can replace them with 12AX7's, but does the 12AT7 have to be replaced with a 12AT7?

The reason I'm asking is I can pull the 12AX7's from my Ashdown Fallen Angel and replace the 7025's in the Bassman and if I could also replace the 12AT7 with a 12AX7 it will save me time and money.
#2
yes a 12at7 has less gain which is often used to "tame" a high gain amp a little bit.

Its an endless world of different tones when it comes to the different types of preamp tubes.

edit: oh and yes you are correct. The 7025, ecc83, 12ax7 are all the same tube just different industry name. cheers
I would rather be a good liver than have one
Last edited by twistudriffer at Sep 12, 2009,
#4
oh and man, I hope your not putting stock ashdown tubes in that bassman. That ashdown most likely came with cheapy tubes. Its like putting walmart tires on a lambo. just my 2 cents. could be wrong tho. cheers
I would rather be a good liver than have one
#5
Quote by twistudriffer
oh and man, I hope your not putting stock ashdown tubes in that bassman. That ashdown most likely came with cheapy tubes. Its like putting walmart tires on a lambo. just my 2 cents. could be wrong tho. cheers


Oh no, they aren't stock. I've had the Ashdown for a few years now and changed the tubes within the past year, so they are fairly new.
#6
k sounds good. How do you like your ashdown? I've always wondered about them but have never been able to even demo one
I would rather be a good liver than have one
#7
its my understanding you can mix and match power tubes as much as you want.

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#8
Quote by twistudriffer
k sounds good. How do you like your ashdown? I've always wondered about them but have never been able to even demo one


Its an amazing amp. Its surprisingly versatile. Its a bit on the dark side and it can be kinda muddy depending on what guitar you're using but overall its a great amp.
#9
Hey Will, you can mix n' match preamp tubes to a certain extend. There are some exceptions ( like cryo treated tubes and what not) but any 12ax7 or 12at7 will do. And like twistudriffer said some tubes are the same type with different names based on the region.

12at7 has a little less gain and more definition than a 12ax7. Tried that myself once but didn't like it. May work for you though. 12at7 and 12ax7 are interchangeable in any case (which was your question).
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#10
Quote by Silver-spear94
its my understanding you can mix and match power tubes as much as you want.

your understanding is wrong.
some amps can run different types of power tubes but most amps are biased for 6L6 or EL34.
#11
power tubes have to be matched! all of them or it will sound like ****
tone slut

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#12
Quote by Mark G
Hey Will, you can mix n' match preamp tubes to a certain extend. There are some exceptions ( like cryo treated tubes and what not) but any 12ax7 or 12at7 will do. And like twistudriffer said some tubes are the same type with different names based on the region.

12at7 has a little less gain and more definition than a 12ax7. Tried that myself once but didn't like it. May work for you though. 12at7 and 12ax7 are interchangeable in any case (which was your question).


Alright. Thanks Mark!

I'd just like to try out some different tubes in the Bassman before the show tonight, just to experiment with different tones.


And by the way, 3 of the 4 people in the band have voted me in - I just need to sway the rhythm guitarists' opinion.


And I went to their show last night - the other guy auditioning totally sucked. He only knew like 1/4 of their set list (and he's had a week longer than me to learn it - i learned the whole thing in like 5 days ) so all night him and the rhythm guitarist were switching in and out of the bassist position. Then the songs he did play he either completely ****ed them up or he just rolled the volume completely off on his bass and pretended to play !
#13
Quote by i_am_metalhead
Alright. Thanks Mark!

I'd just like to try out some different tubes in the Bassman before the show tonight, just to experiment with different tones.


And by the way, 3 of the 4 people in the band have voted me in - I just need to sway the rhythm guitarists' opinion.


And I went to their show last night - the other guy auditioning totally sucked. He only knew like 1/4 of their set list (and he's had a week longer than me to learn it - i learned the whole thing in like 5 days ) so all night him and the rhythm guitarist were switching in and out of the bassist position. Then the songs he did play he either completely ****ed them up or he just rolled the volume completely off on his bass and pretended to play !




You know why that rhythm guy is being all anal?

Experiment mostly with the phase inverter and the V1 position. These will make the biggest difference.
WTLTL 2011