Other Amps

RCA 12ax7 - Black plate vs Grey plate?


I'm looking around for some NOS tubes to drop into my tweed princeton clone, and I'm a total newbie to NOS. I know RCA black plate tubes have a good reputation and are scarce as a result, but I see grey plate more readily available. Are they not as good as the black plates? Would a grey plate 12ax7 be a good match for a tweed amp, or not so much? Or am I overthinking it?


Built, I'm a fan (based on my ears) for any RCA in that tweed circuit.

Not sure of the exact differences between the black and grey, but RCA's in the preamp spots of tweeds always sounded just "right" to me.


Oops! Did I say 12ax7, I meant 6V6. Too much tube hunting in the last 24 hours. I'm getting things mixed up. :) Though the black-vs-gray plate question is still valid.

Thanks for the input JD.


Blackplates are "it", but a close second is the Westinghouse-Marconi "Coke Bottle" 6v6's.

Once again, to my ears.

I'm sure that you'll like a greyplate too, but as usual YMMV when it comes to hearing tube specifics.

Any NOS/ANOS sound better than new production IMO


I was running a Marconi in a single ended amp and whoa I liked it! Really liked it!


I got to try RCA blackplates and grey in my '58 GA40 Gibson. At least in that amp, blackplates were the clear winner.

The greyplates are pretty close. They're both great tubes. Another old pair I'm liking is Brimar, 6v6GT I think, blacked out glass. MD


I usually consult the reviews on watfordvalves. I don't pretend I get them 100%, but they do give some idea of what the differences in sound are for different brands (NOS and new).

Here's their page.


Another gateway lost response.

The NOS JAN 6v6 Sylvanias in my Club Deluxe were great.


Everything you wanted to know about 6V6 but was afraid to ask! http://www.youtube.com/watch?v=00s-CpWZf-M

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