Tube ID Help 12ax7

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japetus

japetus

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Found these in a box at my friends parents house that are moving. Any idea what they are? There is faint red lettering...RCA? USA 7025 stamped
9D0698AE-2ABE-4960-A91E-CC725570FDAE.jpeg
 
Based on the U.S.A style/font of the printing they look spot on to what’s on my vintage GE 12ax7s
 
Tough to tell with just one pic, but I'm thinking they are likely RCA. GE etching is a bit different . Plates don't look GE.
 
psychodave said:
Tough to tell with just one pic, but I'm thinking they are likely RCA. GE etching is a bit different . Plates don't look GE.
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If they are RCA, then they will sound close to the GEs and have more headroom. At least that’s my experience with both brands. Not a gainy tube but super clear, well rounded.
 
Racerxrated said:
If they are RCA, then they will sound close to the GEs and have more headroom. At least that’s my experience with both brands. Not a gainy tube but super clear, well rounded.
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IME GE’s and RCA’s sound quite different other than both having that American voicing with that more hollow midrange vs the European ones

I found RCA’s: dark, smooth, fat, big bottom end, robust, more headroom like you said, very old school voicing

GE: brighter, more sparkle, more dainty/delicate voicing

These tubes IME shine in American amps like Fenders. GE’s imo are really a great fit in blackfaces. RCA’s imo good in tweeds and especially good in those small low wattage American amps like a champ. They kill in my friends ‘60’s 6 watt Gretsch 6151 combo

OP, they should sound very good in the bassman. Guessing you’ll probably prefer ECC83’s in the SLX, but may as well try these since you have them. Wasn’t crazy about them in my various Marshall’s fwiw
 
I don't think there are any wrong answers in the thread. It is really hard to determine some tubes since there was so much relabeling happening. I went through a bunch of my tubes and I found examples that were somewhat similar and different from the pictures posted above. The tube in the OP could be GE or RCA. The etching looks similar to GE... but the USA above the 7025 is what I'm hung up on. RCA usually put USA above, GE usually etches it lower down on the tube. I didnt even get into the getter differences. :hys:

My final answer is I don't know what the tube is. :LOL:
 
The Font looks like what GE uses..
7025 is low noise, so whatever they are, keep them!
 
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