Matched Quad (4). Long Ribbed Plate. Made very early in 1956 with small logo. Diamond on Bottom. Tested in my preamplifier to make sure working as intended with no issues at all. I will almost always reply at least within 24 hours.
Quad 4 Conn by RCA 12AU7A ECC82 Tubes, Closely Matched, Clr Top, Lg Pl, #2
From a larger lot of RCA / Conn tubes mostly from the 50s/60s. Tube are matched by Gm. Power tubes like the 6L6 are tested only with the 686 which includes plate current (Ip), shorts and gas tests.
HIT-RAY HITACHI 12AU7A Tube Halo Getter Japan Matched @90/90 on B&K 606
Hit-Ray (Hitachi) 12AU7A halo getter tube. See photos for test results.
1952 Tung-sol 12AU7 Tiny O Getter NOS Long Gray Plate Amplifier Tube
NOS tubes fall within the Gm characteristic range of an average tube, as published in the RCA RECEIVING TUBE MANUAL, which states “Individual tubes, like any manufactured product, may have characteristics that range above or below the values given.
x3 Triad Pair NEW National 12AU7A ECC82 Audio Amplifier Electron Vacuum Tubes i6
x3 Triad Pair NEW National 12AU7A ECC82 Audio Amplifier Electron Vacuum Tubes i6 NEW OLD STOCK OPENED BOX TO CONFIRM CONTENTS YOU ARE RECEIVING x3 TUBES AS PICTURED
2 NOS NIB Gm Tested National RFT East Germany ECC82 12AU7A Audio Amplifier Tubes
Here’s a pair of NOS East German RFT 12AU7A /ECC82 tubes. On my B&K Gm tester where it reads from 0-120% of new tube value, these test 91-100 and 93-99. Sold by National Electronics in the US.
Matched Pair RFT ECC82/12AU7 O-Getter Strong
Matched Pair. Tightly matched pair! ____ ______. Tested in my preamplifier to make sure working as intended with no issues at all.
National 12AU7 / ECC82 RFT East Germany Tube – Strong Tested, Low Microphonic/
National-labeled 12AU7 / ECC82, made in East Germany by RFT. This tube tests strong and well balanced on both sections. Test results: Gain: 16.4 / 16.1 mA/V: 1.45 / 1.44 Noise: -84.8 dB / -85.7 dB Microphonics are very low — only a barely audible tap when touched, with no ringing, lingering, or feedback.
MATCHED PAIR NOS NIB CV491 12AU7 RFT GERMAN MANUFACTURED HIGHLY RATED
ONE OF THE FEW 12AU7 THAT IS MUSICAL, DYNAMIC, CLEAR, CLEAN AND FOCUSED! IN VARIOUS NOS BOXES. PROFESSIONAL MATCHING TO WITHIN 6%. Best of the lot -RFTs – linear, clean. Good transparency and detail.