Matched Pair Sylvania 7C5 Vacuum Tubes Gray Glass 6P14 I am playing them now

I am playing them now in my Radio Craftsman RC-2 mono blocks with Pink Floyd's "Obscured By Clouds" and they sound terrific

new in box US-made 6KU8 tubes tested to spec on our Paul Hart-calibrated TV7/U

steel support rods and outstanding flashing

This variety has black

Matched Pair Sylvania 7C5 Vacuum Tubes Gray Glass 6P14 I am playing them nowThis matched pair of Sylvania gray glass 7C5 tubes was tested on our Maxi Matcher 2 with 400 volts on the plates and a bias of 36 volt for shorts, gas and transconductance. There were no shorts or gas. Transconductance measured 2340 micromhos with a plate current draw of 24. 5 milliamps for Tube One and 2070 25. 2 for Tube Two. (New US made 7C5s typically test with plate current from the mid teens to mid 30s with transconductance from 2300 micromhos