I have an ARCHON 100 WATT (2015), an ARCHON 25 WATT COMBO (purple of course 2016). And! I'm waiting for an ARCHON 15, I mean an MT15 to be shipped. I'm not much a tube guy but the 6L6 sounds great for what I'm doing. Drop F tuned metal 8 string. My question is. Can tubes from these three amps be interchangeable? In pairs of course. I would greatly appreciate any advice, do's & don'ts, past experiences, benefits. Thanks in advance!