This tester does not test octal tubes, only 9 pin tubes.
Tube Tester Option
https://www.ebay.com/itm/233953776139?chn=ps&mkevt=1&mkcid=28
With all the money I "gamble" on audio, maybe I should just buy this and try it.
With all the money I "gamble" on audio, maybe I should just buy this and try it.