3 amp choices help

[enrique]

A buddy of mine is asking for info on 3 used amps he's looking at and intends to purchase 1 by this weekend.I dont know enough to really advise him,which is why i'm asking here.The amps are a PS Audio hca-2, a Marsh a400s or a Conrad Johnson mf-2200.All three are at the same price are online and cant be auditioned,but could be returned if there was a problem.His speakers are 90db/4-6ohms.He's using a receiver now which he's not going to change.He just wants to add an amp for more headrooom and such.I dont think he needs an amp but regardless he's dead set to get one.He says it wont hurt and would just make things better.Between these 3 amps i mentioned what can i tell him.He likes warm sound and it's for hT as well as 2channel.thanks

[Sonnie]

I'd say he'd be happy with either three and probably would not notice much of a difference. Buy the one with the best warranty and least expensive.

[Otto]

I kind of agree with Sonnie. I believe those are all nice amps. The PS Audio looks awesome. Without being about to audition any, just go for one of 'em. I'm sure any will offer outstanding results.

[F1 fan]

My pick of that litter would be the Marsh because it is a solidly engineered classA/B/ design.The PS unit is a class D (digital)design,although its compact and cool running for it's power rating, it may not be in the top tier sound wise.The CJ appears to be a hybrid tube /mos fet design so it will need periodic tube replacement.