NOS. Labeled and boxed as Philips. Blackburn "B" production codes.
NOS in original box. Only one in stock.
NOS in original Siemens Rohre orange and blue boxes. Steel pins.
Lightly used, test as new. Mid '60s. Small getter ring.
1970s Vintage, god pins. Made in Czechoslovakia
A significant upgrade to new production ECC88/6DJ8/6922s. Sold in white boxes.
Hey Mike - those Tesla ECC88s work great in the Avalon VT-737 mic pre. I did a before/after comparison using a MIDI file and the sound quality is significantly improved. The stock Sovtek 6922s were slightly noisier (or at least one of them was) but more importantly the Teslas offered more clarity across the board.
Thanks again, great service --