We also check our tubes for other issues like shorts on calibrated and vintage tube testers. We match our tubes +/- 5% with an overall tolerance of 10%. While we do screen for noise and microphonics, even the best tube testers are quite bad at finding these faults. The only real test is with your ears.
We guarantee that our tubes will be free of noise or microphonics but please be aware that there isn't a whole lot we can do to ensure your tube won't be. We guarantee our tubes for 90 days upon receipt.Noise and/or microphonic issues are covered. This item is in the category "Musical Instruments & Gear\Guitars & Basses\Parts & Accessories\Amplifier Parts". The seller is "onlyglass" and is located in this country: US. This item can be shipped worldwide.