1 low noise pair) 12AU7=ECC82 Mullard UK NOS ribbed plates same build

1 tube) 10.8/10.2ma Gm=2200/2100 (1963) Mullard faded printing - on left

1 tube) 11.8/10.7ma Gm=2200/2100 (1966) Mullard branded GE

Tested on Amplitrex

Good Ma range 8-10ma

Good Gm range 1800-2200

great midrange and good bass 

Low Noise and not microphonic 

Recommended for

- Concert Fidelity CF-080LS Hybrid Line Stage Preamplifier
- Ampeg SVP-PRO Bass Preamp
- Velleman K4000 kit
- Audio Note CD2
- ROTH AUDIO MC4 MUSIC COCOON 2009
- Eastern Electric Minimax
- Hovland