I own a 2/90/2, and absolutely love it… I run a Helix into it, and the 2/90/2 into a ISP Vector SL and then into a Mesa OS Recto 4x12… amazing sound, but the weight of that thing is unbelievable (wah wah… I know). I only use one channel of the 2, and am wondering if moving to the PS-100 would be the same as what I am doing with the 2/90/2 (except less weight, and having the attenuation feature for my other amps at home). I’m also curious tone-wise is moving to the LXII would be a noticeable difference or not. I do love the 2/90/2, but the weight and the eventual costs of replacing quads of KT88s (as opposed to a pair of KT88s or a quad of 6L6s) is not necessarily what I need in my rig. We don’t have any dealers here (Durham, NC), so I can’t try before I buy. Of course, I may just buy to try.
Also, considering replacing the Mesa 4x12. I’m guessing the Fat Bottom 4x12 would be closest for what I do (high gain metal & hardcore), but curious if you all think differently for me to consider the Deliverance 4x12
You pretty much answered your questions, but let me take a shot at it.
You’re only using one channel, so that’s a point in favor of the PS-00.
As you said, the PS-100 offers other benefits, whereas the LXII is another slightly smaller lighter and lower powered version of what you have now.
The LXII occupies 1 rack space compared to two for the PS-100, but the PS-100 is 15 Lbs vs 20 for the LXII.
The 2902 is 100W per channel and generally has more headroom than the LXII. Because you are only using one channel, that channel has more headroom than running both channels simultaneously. That makes the PS-100 more comparable to one channel of the 2902 sonically and dynamically, whereas the LXII running bridge Mono will also produce 100W, but with less dynamic range than the 2902 or PS-100.
My conclusion is that based on cost, weight and side benefits, the PS-100 wins.
Regarding the cab, it depends on which Mesa you are talking about. If it’s a recto cab, the D412 is closer in sonic behavior than the Fatbottom. But the Fatbottom is tighter and has better low end definition. So, if you’re looking to stay with a more forgiving cab behavior, go with the D. If you want more bottom end definition and don’t mind that it will be more directional out front, go with the FB.