(!!!!) (Best Pair) CV4003=12AU7=6189 Mullard UK NOS 1978 rebranded "6189 RTC" 1981 (10.2/11.2ma and 10.4/11.2ma) 1-2% matched

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