12AT7 in PI in a Marshall amp? What effect on tone?

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redrol

redrol

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Just curious, I have heard various people like to put these in the PI in Marshall amps. No idea what it might do to the tone however? :confused:
 
it didnt change the tone in mine. 2204 ish stuff. Something about Idle Current that I read from Myles Rose. Im leaving it in there. It just seems more immediate and focused.
 
interesting, so no adjustments needed, just put in a 12at7 in the pi? I know this is even remotely the same circuit, but I had a Mesa V-twin that sounded kinda grainy with 12ax7's - popped 12at7's in and it got real smooth.
 
Darren you going to be at NAMM? I have something for you to hear. Stop by Minarik
 
jerrydyer":2w36yxyt said:
Darren you going to be at NAMM? I have something for you to hear. Stop by Minarik


yeah, I'll be there - and will do - what day?
 
I think IM taking friday off so Friday and saturday and sunday afternoon to pick up my stuff. I have a higher gain thing to show you, and one mod lets you knock off about 50% of your volume cranking the master so you get a saturated sound at bedroom or recording levels. Pretty cool. A little more agression and modern sounding.
 
jerrydyer":31yr1r6q said:
I think IM taking friday off so Friday and saturday and sunday afternoon to pick up my stuff. I have a higher gain thing to show you, and one mod lets you knock off about 50% of your volume cranking the master so you get a saturated sound at bedroom or recording levels. Pretty cool. A little more agression and modern sounding.

cool!
 
I run an AT7 in my amp. THe tone is more glassy and dynamic; less saturated. But if you're using a ton of gain, you might not notice a huge difference.
 
Actually works well in the 6550 equipped amps. THe 12AT7 has lower gain, but more current drive. A 12AX7 is a little weak on drive for 6550's IMHO.
 
Carol-AnnAmps":vm8dws8b said:
Actually works well in the 6550 equipped amps. THe 12AT7 has lower gain, but more current drive. A 12AX7 is a little weak on drive for 6550's IMHO.

Would that apply to EL34s too or does it not drive them the same as 6550s.
 
reviving an old thread, i'm interested in putting a 12AT7 in the PI of my TSL100... any reason against it?
 
There's no reason against it. It will knock the output down a bit. Try it and see if you like it.
 
steve_k":3nrkyjhh said:
There's no reason against it. It will knock the output down a bit. Try it and see if you like it.

well i have read it has less gain, but can supply far more current than a 12ax7.. is this an issue for the power section or no? Has anyone tried this in a JCM2000 amp? I was thinking of doing it because it might sound better?
 
I run a 12AT7 PI in my Mesa. Huge improvement with that amp IMO. Fryette doesn't recommend it in my SigX so I gotta go with what they say. I'd check with amp manufacturer to be safe.
 
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