Sylvania 5933 807W FU7 Vacuum Tube 13GB5 Plate Cap

Sylvania 5933 807W FU7 Vacuum Tube 13GB5 Plate CapThis Sylvania 5933 807W FU7 output tube was tested on our Maxi Matcher 2 for shorts, gas and transconductance with 400 volts on the plates and a bias of 48 volts. There were no shorts or gas. Plate current draw was 17. 2 milliamps while transconductance measured 2050 micromhos. (New 5933s typically test from the mid teens to mid 30s with transconductance from 2200 micromhos). I am playing it now in my Musical Paradise 301 MK 3 (with an adapter, not

This trio of US-made 6X4 tubes was tested on our Paul Hart-calibrated TV7/U for shorts

It measured 73 where minimum (65%) is 50 and 100% is 77

new in box RCA Black Plate 6BK7B tube tested to spec on our Paul Hart-calibrated TV7/U

4-17 188-5 and 2-48 188-5 date/provenance codes

new in box GE 33GY7A tubes tested to spec on our Paul Hart-calibrated TV7/U

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

gray plates and bottom

the centering pin is missing on Tube One and Tube Two's base is cracked

On the Maxi-Matcher

" replicating this album's nuances and dynamic range with precision

53/52 and 54/54 where minimum (65%) is 40/40

" "My Darling's Ring