#1
Alright,

I'm buying some new valves and my amp needs 2 regular 12AX7s in V1 and V2 and apparently needs a balanced 12AX7 for the phase inverter in V3...

I messaged a shop on ebay to see if the valves i was looking at had a balanced one.

This is the reply i got:

Hi, The pre amp tubes we sell with all our kits are balanced within the industry recognised tolerances and are easily balanced close enough to be used in V3 position. So you can actually use any of the 3 12AX7's in this kit for your phase splitter. However we can mark the most closely balanced tube for you with a label on the tube box and a blue spot on the glass base between the pins if that helps.


Just wanted to clarify that he is right.

Is he?
Last edited by guitarcrazy1991 at Feb 2, 2008,
#5
I use www.banzaieffects.com, as they tend to be much cheaper than most UK places, check their prices.

But... You can get away with not having a matched PI, if he says his are matched to a degree anyway it's fine.
The Laney Thread are big and clever. No exceptions.
#7
What ebay shop is it?
Gear:
Epiphone SG Standard - Natural Wood Finish + SD Alnico Pro 2 Bridge Pickup
Epiphone Les Paul Standard - Limited Edition Green
Ibanez S470
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Harley Benton 2x12 Vintage 30's
Vox AC4TV
Vox VT15
#9
Quote by guitarcrazy1991
Hmm, do you have any idea of the advantages of a balanced 12AX7 for the PI?
Same advantage as having a matched set of power tubes. It gives a slightly more even load to each side of the push-pull power circuit, makes it better balanced. No idea what it does to tone exactly.
The Laney Thread are big and clever. No exceptions.
#10
Quote by guitarcrazy1991
Hmm, do you have any idea of the advantages of a balanced 12AX7 for the PI?
Yeah, it insures that you get the maximum headroom before you go into clipping in your power amp, and that both sides start to clip at the same level. That last part minimizes even order harmonics.

But back-in-the-day, some guys would intentionally offset the drive to the output tubes to add some even order harmonics.
Meadows
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#11
Hmm, as long as it won't 'splode my amp then it's cool. The guy said they're balanced to a degree anyway...