Sylvania 12AU7 12AU7A NOS-Testing Copper Support Rods Triple 3 Mica For Your Bottlehead Univalve Chad Mitchell Trio It sounds very good with

It sounds very good with an occasional pop and tick audible in the pianissimo passages

Otherwise it is sold as-is with no returns

There were no shorts or gas

but not in guitar amps and other environments with loud noise and/or excessive vibration

This lot of three Ken-Rad 6D6 tubes was tested on our Paul Hart-calibrated TV7/U for shorts

Sylvania 12AU7 12AU7A NOS-Testing Copper Support Rods Triple 3 Mica For Your Bottlehead Univalve Chad Mitchell Trio It sounds very good withThis 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