#1
Just looking at the chassis of my Peavey JSX and I'm just wondering what's the preamp tube beside the power tubes for? It has a slightly higher casing and on the manual it says that it has 3 12AX7 preamp tubes.

Am I missing something?

PS: Stole the image off eurotubes, therefore, no comments about the carpet...
Last edited by conor-figgy at Apr 17, 2011,
#3
Rectifier? PI? Tube driven effects loop?
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#6
Quote by Robbgnarly
it's the phase inverter

Grand, now is there any reason why that tube alone is a Sovtek and the rest are JJ's?
#7
You can use any manufacturer's tubes anywhere as long as they can go in your amp.

Of course, you can't just swap out 6L6 with EL34 or any of the power tubes (unless your amp lets you, like mine), but preamp tubes can be whatever.
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#8
Quote by stratman_13
You can use any manufacturer's tubes anywhere as long as they can go in your amp.

Of course, you can't just swap out 6L6 with EL34 or any of the power tubes (unless your amp lets you, like mine), but preamp tubes can be whatever.

Ah ok! But the power tubes are 6L6/EL34 convertible by the flick of a switch with biasing but my 6L6's are being run in the EL34 mode as they tend to run cooler in the 6L6 mode and warmer in EL34.

Ok thanks guys! I think I'll switch out that Sovtek anyway.
#9
Quote by conor-figgy
Grand, now is there any reason why that tube alone is a Sovtek and the rest are JJ's?


That might be the Sovtek 12ax7lps which is great for the phase inverter. This tube has nothing to do with tone, the jjs are.
Parker PDF30
Vox VT40+
#10
Quote by OldRocker
That might be the Sovtek 12ax7lps which is great for the phase inverter. This tube has nothing to do with tone, the jjs are.

Just checked, how right you are! It is a 12AX7LPS. Maybe I won't switch it out!
#11
Quote by conor-figgy
Ah ok! But the power tubes are 6L6/EL34 convertible by the flick of a switch with biasing but my 6L6's are being run in the EL34 mode as they tend to run cooler in the 6L6 mode and warmer in EL34.

Ok thanks guys! I think I'll switch out that Sovtek anyway.

After reading this I was about to say "Oh, you have a JSX?" and then I read your sig.
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How do you say "I'm okay" to an answering machine?

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#12
Quote by stratman_13
After reading this I was about to say "Oh, you have a JSX?" and then I read your sig.

Yeah, just bought it, €620! The previous owner got a tech to change out all his tubes and it looks like I've gotten quite lucky.................I think.