Not contesting that. Just keep in mind that the OP already had a Triaxis and wanted something different. (Well, ok, a Triaxis rig does not sound exactly the same as a Mark amp but it is close enough.)The JCM800 and the Mesa Mark III were kind of the main amps used in a lot of 80s hair/metal bands... If they didn't use those amps, they usually used rack mount preamps (like the ADA) and mesa power amps. So the Marshall and Mesa suggestions are pretty spot on.
JVM? Sorry, no cigar. Not even close actually. The JVM is a nice and versatile amp on its own right but don't except to find the classic JCM800 crunch in there.Can the JVM or a DSL do the 800 thing?
2204 can blow your eardrums just as easily. Understand what you are getting with an 800before you dive in:Honestly if the triaxis doesnt cut it, maybe buy a JMP-1 to compliment it? I have both and they are different beasts. You could try and engl but thats a very modern nu metal sound (roughly speaking). tele_jas has a point about the ADA pre's but those are starting to breakdown with age and repair can be super expensive.
But the jcm800 suggestions are probably the best bet. Get the vertical jack model, not the horizontal model. 2204 if u like to enjoy the tone without blowing your eardrums. 2203 if your name is angas young or slash and you have a football field of people to please.
To me the 80s hair metal was always demonstrated with the absolute walls of 1960A and B cabinets on stage. Marshall was the sound and the 800 series had gain and then some. They can also be rebiased to take KT88s and other tubes, so theyre seriously versatile.
JMP/JCM 2204/3 and a boost. When your done with the 80's high gain sound, turn off the boost and the amp will do just about anything.
It IS THAT SOUND,.....everything else will be an interpretation, approximation, imitation. IMO