Join Date: Dec 2000
Location: Longmont, Colorado
Re: When switching the tube..
You just stuck the 6L6s in and went for it? Does the TSL 60 have a switch for 6L6s? They are probably over-biased (I think, don't remember the specs off the top of my head) and one of the tube types has an extra ground pin that the other one doesn't, again, I don't remember off the top of my head, but if it's not wired correctly, it may be a short lived happiness.
Again, if it has the switch for 6L6s, it should be fine, otherwise check with a tech.
*edit* I just looked up the manual at marshallamps.com, it doesn't say anything about the TSL60 being 6L6 compatible, so, you're on your own. The 2 tubes aren't direct replacements for each other.