$350 Shipped CONUS!
All test at 72 on my calibrated TV-7. New 6550's test at around 66 with this tester. Perfectly matched quad.
The far left tube is labeled RCA, the next one is labeled GE, and the two on the right are Tung-Sol labeled. Guide pin is broken on one. They are all identical construction.
These have been amp tested with 500V on the plates. Biased up just fine and sound great! I played them for a day with no issues. No surprises.
The date codes left to right: 6448 (RCA), SU 188-5 (GE), 3227236 (Tung-Sol), 3227236 (Tung-Sol).
Tired of running through new production output tubes? These are the answer. These 6550's are tough as nails. There is at least 10 years worth of listening here folks. No joke.
