Baldwin branded Sylvania 12AX7 tubes

[Randy Magee]

Weren't these tubes selected for low noise/microphonics? Would they be a good candidate for an Express or Liverpool build?

[brentm]

Not sure if they'd be good for the Liverpool or not. But there are three different manufacturers when it comes to Baldwin 12ax7 tubes in circulation (that I know of).

The brown silkscreen labels, I believe are RCA knock-offs. They have an octagon 12ax7 which looks strikingly similar to the RCA, but it's larger in size. I believe I traced these back to Japan in my research. Long plates, sound amazing in my opionion.

The green labels are the sylvania tubes.

Yellow ones with black plates I believe are Raytheon.

I haven't found much use for the green or yellow Baldwins. I know the Raytheon black plates are fairly sought after tubes.... but I do love the Japan tubes.

[passfan]

Sylvania will have a 312 manufac. code printed on the tube. Usually a 17 mm grey plate structure with green print on the glass. You see them on ebay all the time.

[thejaf]

I have a few of the green 12AX7s in my stash. I don't quite care for their sound in my guitar amps (too stiff), but they have very strong output (peg my tester compared to new production tubes). May be a good choice for PI though, I may try that.