NOS Valve Identification

[JacksonRR]

So I picked up 8 NOS valves today for five bucks a pop. The cherry on top is the guy lived in a town called Gainesville.  :D

Here's what I bought:

2 Mullard 12AU7s
3 GE 12AT7s
3 RCA 12AX7As

Ok so here's the thing. 2 of the RCAs are stamped GT BRITAIN while the other is stamped U.S.A.. The G.B. stamped ones have the same seam on the top where the glass comes together as the Mullards and the boxes are identical in length and shape to the Mullards. The U.S. stamped one is in a shorter box, identical in length and shape to the GE boxes, also same smooth seam. The Mullards and the GB stamped RCAs have a heavier weight to them, while the US ones are a bit lighter. edit: Can the GB labeled RCAs be Mullards?

I'm pretty drunk right now and waiting on my stupid phone to actually send pics, but I do have some, somewhere in space/time. I thought they'd be in my e-mail by the end of this, but they are not. I will post them later when my retarded carrier decides that that info deserves proper routing.

Thanks guys for any input you can give based on my words.

[Transcend]

I have no idea but if you have an android phone just get the dropbox app its far quicker!

[Elliot]

Could be - I know that Mullard made some GE labelled 12AX7s for the US market.  I also know that RCA was tied in to the Genalex/Marconi-Osram plants in GB so it is possible they are Genalex/Marconi-Osram.

[JacksonRR]

Thanks on both! I'll have to try that app, I have a Samsung Galaxy S. I did try them out this morning in my 5150. Ended up putting my GE 12AX7s to rest. One of the GB RCA 12ax7s was really crisp and had a tight and subdued low end, really loved V1. The US one loved V2, where my cold clipping happens. From HTHs description of them, that made sense that it liked being there. The other GB RCA worked wonderfully in V5, which feeds my tone stack. One of the GE 12AT7s was killer, much better than any of my 12AX7s for the effects loop, the others still good, but not impressive. One of the Mullard 12AU7s is in my phase inverter now and I hope it never dies. One was OK, but the other imparted a really nice sound. Very crisp and airy, no extra distortion and kept things very meaty. Right now, I'm 100% happy with that purchase. Very much worth the price and the time I spent trying every combination of the valves I had and the ones I just bought.

pics!

The whole package


GT BRITAIN stamped RCA


USA stamped RCA


Mullard 12AU7

[HTH AMPS]

Mullard ECC83/12AX7s all have the production codes etched into the side of the glass near the base - if you have them on your RCAs, they're likely Mullards.

The RCA 12AX7s I've had all sounded like Mullards with that crunchy midrange, so maybe they had all been Mullards - or maybe they just sound similar by chance.

Either way, great valves - nice score!  PDT_003

[MrBump]

I have no idea but if you have an android phone just get the dropbox app its far quicker!

Doh!  I never thought of doing that!!!

Nice one!!!

[Transcend]

I have no idea but if you have an android phone just get the dropbox app its far quicker!

Doh!  I never thought of doing that!!!

Nice one!!!

It's an absolute essential for me.

If i don't do that i either have to email them which can take forever depending which way the wind is blowing or find the usb cable for my phone which i never have any idea where it is

[JacksonRR]

Cheers HTH! Turns out the one that I thought was amazing in V1 was indeed a Mullard. Had to go searching on Google to identify the markings, but that's what it is! The other GB one, who knows. Read rumors of those coming from a few places, but it sounds pretty good, whatever it is. Might be from Yugoslavia. I have a very nice sound coming out of these G12T-75s atm. Very thick, warm, balanced, less fizztacular, still defined and super-clear pinches.

[HTH AMPS]

excellent tone wins the day, yay!