Selling on behalf of @chelseadave who was kind enough to send them to me to try.
They are a well-matched pair of what is the most desirable 12AU7 RCA ever made.
When I say well-matched: both tubes measure within 2% on my tester, and each side of each valve measures within 2% of its counterpart.
The construction is highly unusual with an oblong getter on the side of the tube instead of the top, which is said to contribute to low microphonics. Long, grey, ribbed plates are of course de-rigeur.
I’ve tried this pair in my pre: they work flawlessly and sound really good - giving a very lively, extremely 3D sound. I’d keep them but I can’t afford them all.
In NOS they make anywhere from £100 to £200 per matched pair. These are not NOS: they don’t have original boxes, all of their print has been rubbed off, and judging by how they measure, they’re about 40% or so into their life. No-one else has made or faked these, so you can be sure they’re genuine.
So, how about £60 inc. postage? I think this is a bargain, especially if you use them in a circuit that’s not running them hard - these old tubes tend to be long lived.
well I better sell it than.