1 very low noise pair) CV4003=M8136=12AU7=6189 Mullard UK box plates NOS 1978 rebranded "6189 RTC" 1981 in white boxes (RTC=Radiotechnique, France)

1 section) 10.2/11.2ma Gm=2300/2400

1 section) 10.4/11.2ma Gm=2200/2300

Tested on Amplitrex

Good Ma range 8-10ma

Good Gm range 1800-2200

great midrange and good bass

Low Noise and zero microphonics

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

- Schiit Vali 2