(!!!!) (Recommended Single) 7199 RCA black plates NOS 1960's (19.5ma pentode / 8ma triode)

7199 RCA black plates NOS 1960's faded printing

19.5ma Gm=8800 (pentode section) strong

8ma Gm=2100 (triode section) good

Tested on Amplitrex: 

Good Pentode Section 10-12ma Gm=6000-6500

Good Triode section 7-9ma Gm=1900-2100

- Bogen BD-212
- Dynaco ST-70, SCA-35
- Ampeg B25, B25B
- Heathkit AA-111
- Stromberg Carlson
- Ampex Concerto 1961
- Scott LK 150