Sylvania JAN CHS 6SN7W Vintage Tube Pair Black Plates Chrome Dome (Test 85%)
Take a look at the photos and test results below. You'll see we've also created a guide to help you interpret the test results. We're here to help, so let us know if you have any questions. Thanks for looking!
| Plate 1 | Plate 2 | |||||||
|---|---|---|---|---|---|---|---|---|
| Plate Current (Ip) | Mutual Cond (Gm) | Heater-Cathode Leakage | Gas | Plate Current (Ip) | Mutual Cond (Gm) | Heater Cathode Leakage | Gas | |
| Tube 1 | 8.4 mA (93%) | 2300 (88%) | 0.0 | 0.2 | 7.0 mA (78%) | 2300 (88%) | 0.0 | 0.2 |
| Tube 2 | 7.6 mA (84%) | 2300 (88%) | 0.0 | 0.4 | 6.9 mA (77%) | 2100 (81%) | 0.0 | 0.0 |
Here's some information that will help you interpret the test results!
How do you calculate the percentage shown in the title? This is the average of all test results. This percentage provides a quick comparison to NOS specification.
What is Plate Current (IP)? This is the actual plate current, measured in milliamps (mA). Most people agree that this is the more important measurement when matching power tubes (6V6, EL34, 6L6, 6550, etc). For easy interpretation, we also give you a percentage of the measurement compared to NOS specification.
What is Mutual Cond (Gm)? This is the actual mutual conductance, also known as transconductance. Most people agree that this measurement is more important when matching preamp tubes (12AX7, 6DJ8, 6SN7, etc). For easy interpretation, we also give you a percentage of the measurement compared to NOS specification.
What is Heater-Cathode Leakage? This number should almost always be 0.0. This is particularly critical in preamp tubes (12AX7, 6DJ8, 6SN7, etc), as even the smallest measurement can lead to noise and/or poor performance. This is a test you won't get from vintage testers, at least not with any precision.
What is Gas? This scale ranges from 0.0 to 999.9. It is critical for preamp tubes to have a low test result (less than 0.4 is perfectly fine). Larger power tubes (6V6, EL34, 6L6, 6550, etc) normally show levels as high as 15.0, which is normal given the high temperatures and surface area within the tube. This is a test you won't get from vintage testers, at least not with any precision.
Here's why you should buy your tubes from us!
- We use the most advanced and accurate tester available, the Amplitrex AT1000. This piece of equipment runs tests that vintage testers cannot, ensuring you get a full picture of the tube you're buying. This includes a "noise test" that tests for microphonics!
- We screen each tube for potential issues (faded getter flashing, loose particles in envelope, over-heated plates, etc)
- We offer 30-day returns on all tubes!
- We combine shipping for free, meaning your entire domestic order ships for just $4.90 via USPS First Class. We combine purchases for International buyers as well.
- We've been selling tubes and electronics on eBay for over ten years, and average 99.9-100% positive feedback! To learn more about us, visit our website by clicking here.
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- Read the entire description.
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