(1) Tested RCA 6AU8 Tube Medium Mu Triode Sharp Cut Off Pentode Tube

(1) Tested Zenith 10GN8 Tube High Mu Triode Sharp Cutoff Pentode Tube

(1) Tested Tung-Sol 6AW8A Tube Tung Sol 6AW8 A High Mu Triode Cut Off Pentode

(1) Tested RCA 6JE8 Tube with Box Code AV High Mu Triode Sharp Cutoff Pentode

(1) Tested Sears 8JV8 Tube Japan Date Code 6K High Mu Triode Cutoff Pentode

(1) Tested Sylvania 6GH8A Tube with Box Date Code ae Triode Sharp Cutoff Pentode

(1) Tested RCA 6EB8 Tube Date Code AP High Mu Triode Pentode Tube

(1) Tested Very Strong RCA 6AG9 Tube RCA Medium Mu Triode Sharp Cutoff Pentode