Can I test KT Series tubes on a Maxi-Matcher?

Yes, you can test any KT series tube on a Maxi-Matcher, directly with no additional adapter needed. This includes the KT-66, KT-77, KT-88, KT-90, KT-120, and KT-150. The Maxi-Matcher has four tube measurement sockets, each of which is pinned to the octal standard EIA “7S” / “7AC” pinout. This pinout is compatible with the large majority of beam power pentodes in use today.