This is the new Electro-Harmonix 300B from Sovtek. They've redesigned the filament of the old Sovtek 300B and put a classy white ceramic base on it. Usually ships within 24 hours.
Price is for a matched pair .
These Tesla 300B's are dual point matched for the best musical accuracy possible. Every pair is inspected at the factory and comes with test certificates for each tube. Out of stock. This is the 300B against which all other 300B's are compared. A recent review in Stereophile magazine placed this tube at the top of the 300B category, and this new production version is much easier to obtain than a vintage pair of bottles.