A really nice looking pair of the scarce Amperex USA 6922 (6DJ8 / ECC88).
This is a well matched pair, despite bearing different Ink Stamps -- one is labeled Amperex, the other Siemens. They're both made by Amperex, in the USA, circa late 1970s.
This is a nice looking used set, see photos below for test reports.
Tests made on Lab standard, calibrated Amplitrex AT 1000 computer tester.
No microphonics, no noice, super clean and testing strong. Good letters.
By the mid 1960s, there became notable demand for military and industrial graded versions in the USA, for the 6Dj8. In response Amperex began production at great expense here in the USA. Amperex made these at a facility in Hicksville, NY, back in the day.
At countless audiophile testimony, the Amperex "USA" 6922 tube as is one of the best variants. Best tried once you arrive to the realm of premium gold pin versions. They share the top notch constuction with Amperex's PQ 6922 -- though these were carefully manufactured at the Amperex USA production facility, back in the late 1960s. The version of this tube, is always marked, in tiny etched letter "USA" sometimes with date codes as well.
These are best for audiophiles that have chased the White Rabbit long enough, trying at least the white inked Amperex "Bugle Boys" of the early to mid 1960s; at least that's what I recommend. Once you've ditched your reissue tubes -- and are happy with a set of 6Dj8 Amperex Bugler's -- then by all means, dedicate some coin to the pinnacle of the sector -- that being the highly collectible 6922...
Amperex pretty much perfected the 6DJ8 with the Bugle Boy..used in every critical lab electronic instrument beginning about 60 years ago. If you didn't start of with a set of these early Bugle Boy's -- you're missing out.
The gold pin 6922 brings an even higher quality standard to the table, that being longer life, and to some ears a bit more detail..
These are out of 40 years' storage, as spares and will be a score if you're looking to upgrade your preamp that uses the most excellent dual triode 6Dj8 / 6922! They should be a necessity, really -- and will make for a major upgrade if you are running modern tubes.
The 6Dj8 is a wonderful little dual triode tube for audio uses. Many thanks to our friend Roger Madjestky for popularizing this nearly forgotten tube back by the 1970s. Roger's preamp beginning with the RM-1 was one of the best, still to this day.
