Sylvania 12AU7 12AU7A NOS-Testing Copper Support Rods Triple 3 Mica Vacuum Tube For Your Bottlehead Univalve T15 T03

Sylvania 12AU7 12AU7A NOS-Testing Copper Support Rods Triple 3 Mica Vacuum Tube For Your Bottlehead Univalve T15 T03This Sylvania triple mica 12AU7A ECC82 dual triode was tested on our Paul Hart calibrated TV7 U for shorts, gas and transconductance. There were no shorts or gas. Transconductance measured 73 79 where new nominal is 50 50. This tube has two additional vertical support rods; an additional mica spacer for low microphonics; crenelated, round mica spacers and excellent flashing. I have played it in my Bottlehead Crack headphone amplifier and it sounds

black plates and Micanol bases

round top mica and rectangular bottom spacers

and if you need just one strong section

5 record cleaner and then played on our Rega Planar 3 with an Ortofon X5-MC cartridge on an RB-300 tone arm with a Cern Audio phono stage feeding our Musical Paradise MP-301 single-ended integrated amplifier which drives PSB Alpha Minis

This Tung-Sol 9BR7 tube tested to spec on our Paul Hart-calibrated TV7/U

These three Ken-Rad 1A7GT tubes tested to spec on our Paul Hart-calibrated TV-7/U

There was no gas and it tested 2170 micromhos with a plate current draw of 25

Pictures Three and Four are included to underscore this fact

FOUR-STAR REVIEWS OR HAVE LOST A CUSTOMER BECAUSE I REFUSED TO EITHER ISSUE A REFUND FOR A TUBE THAT WENT BAD AFTER IT HAD BEEN USED OR A BUYER KNEW NOTHING ABOUT TUBE REBRANDING AND CLAIMED THAT SOMETHING MADE BY TUNG-SOL AND BRANDED BY EMERSON WAS MADE BY EMERSON

I have played them in my Radio Craftsmen RC-2 monoblocks (with adapters

This matched pair of RCA-MANUFACTURED 5Z4 rectifier tubes were tested on our Paul Hart-calibrated TV7/U for shorts

Tube Two is a bit microphonic and it is therefore recommended that this matched pair not be used in areas with excessive vibration