I've got 8 very nice NOS 6H23 tubes for sale at a giveaway price of $20 + shipping per pair or all 8 for $70 shipped.
These are the real deal with the rocket logo and sound very nice in my Audion preamp... I wanted these to be a less expensive alternative to my quad of Amperex White Label 7308s, but the Amperexes really are the best of the best (as they should be for ~$500 a quad!).
This tube sounds wonderful. Great extension, nice mids-- a screaming deal.
