i use a lowly B&K but in your case, The ability to properly test the 6H30 is key. I would invest in a backup set from ARC including the key 6550 in the power supply of your DAC, it is way more life limited than the 6H30. Then find a reliable vendor / ARC dealer w tester and have them grade your old tubes.
Anyone Here Ever Purchased A Tube Tester?
Once or twice a day a tube sputters for a brief second in my Audio Research Reference DAC. The Reference DAC is connected directly to my amplifier and it also serves as my preamp. Visually, all of the tubes look fine. Visually, I can’t tell which tube may be bad.
The tubes are: (4) 6H30, plus (1) 6550C and (1) 6H30 in power supply
Have any of you ever purchased a tube tester to test your tubes? If so, what tube tester are you using?