FS: Sylvania 7308 NOS
doctorcilantro
Posts: 2,028
SYNOPSIS - Sylvania 7308 NOS NIB Halo Matched pair $79.50 shipped
Matched pair in original boxes USA made Sylvania 7308, tested on top of the line Amplitrex AT1000. Note: ask any tube tech with a "real" tester and you will find they all encounter NOS 6922 type tubes with high emission. They ALL test this way, EVERY single NOS 6922 I have ever tested; they settle down upon burn-in, and this is a sure sign of a true NOS 6922.
TEST RESULTS (Amplitrex AT1000)
Tube 1
Emission: 225/212 %
Transconductance: 15660/16800uMho (125/134 %)
Tube 2
Emission: 192/174 %
Transconductance: 15890/14600 uMho (127/116 %)
View Amplitrex 7308 test parameters screenshot below.
HiFiTubes brings you affordable, laboratory grade vacuum tube testing. We've all read about how drastically different even identical model testers report. Are your tubes really NOS? We use the Amplitrex AT-1000, the most accurate tube tester in the world, to quickly run the most thorough battery of tests your tubes will ever experience. Modified testers may come close, but this solid state tester with a regulated power supply provides unprecedented high accuracy and repeatability, two founding principles of reliable empirical observation (read "science").
The AT1000 achieves +/-1% accuracy after 10-minute warmup, and it can test tubes at up to 500v (160mA) recreating real world operating points as used in actual circuits. The tubes we test and the tubes we sell are not labeled vaguely as "NOS" or "used". The test setup page displays the parameters and results are put on each box label page. Matched tubes are matched by plate current within 10% and then transconductance by 5%.
Matched pair in original boxes USA made Sylvania 7308, tested on top of the line Amplitrex AT1000. Note: ask any tube tech with a "real" tester and you will find they all encounter NOS 6922 type tubes with high emission. They ALL test this way, EVERY single NOS 6922 I have ever tested; they settle down upon burn-in, and this is a sure sign of a true NOS 6922.
TEST RESULTS (Amplitrex AT1000)
Tube 1
Emission: 225/212 %
Transconductance: 15660/16800uMho (125/134 %)
Tube 2
Emission: 192/174 %
Transconductance: 15890/14600 uMho (127/116 %)
View Amplitrex 7308 test parameters screenshot below.
HiFiTubes brings you affordable, laboratory grade vacuum tube testing. We've all read about how drastically different even identical model testers report. Are your tubes really NOS? We use the Amplitrex AT-1000, the most accurate tube tester in the world, to quickly run the most thorough battery of tests your tubes will ever experience. Modified testers may come close, but this solid state tester with a regulated power supply provides unprecedented high accuracy and repeatability, two founding principles of reliable empirical observation (read "science").
The AT1000 achieves +/-1% accuracy after 10-minute warmup, and it can test tubes at up to 500v (160mA) recreating real world operating points as used in actual circuits. The tubes we test and the tubes we sell are not labeled vaguely as "NOS" or "used". The test setup page displays the parameters and results are put on each box label page. Matched tubes are matched by plate current within 10% and then transconductance by 5%.
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Tortuga Audio LDR passive preamp
Decware EL34 amp
Allnic H-1201 phono
Zu Union Cubes
iFi iDSD DAC, .5m UBS, iFI Gemini cable, Oyaide Tunami XLR 1.3M, Oyaide Tunami Speaker wire 1.5M, Beyerdynamic DT1990 headphones, PS Audio P3 power center