I think you’re really on the right track, other one that really seems up your alley is the viva egoista 845, I would personally actually prefer that over the wa33 stock, but the wa33 elite is a closer comparison for sure. I think it would really depend on what you want to focus on, both are cleaner leaning amps that are very technical with different focuses. The viva focuses a lot more on spatial recreation and stage than the wa33 elite does, it’s much more grand, spacious, and honestly just more impressive than the stage on the wa33 in most aspects, although the wa33 is more faithful to the recording/source and more accurate in placing things naturally, but it’s really hard to ignore the spatial focus of the 845. Dynamically the wa33 does a better job accuracy wise, but the 845 is just more dynamic to my ears but it’s perhaps a tad bit exaggerated there. Resolving power wise, the wa33 elite can pull a bit more resolution and lower level information and present it more faithfully imo, but the 845 isn’t a slouch either. I do personally like the better bite you get on the 845 where you get a bit more softness on the woo but really neither are what I’d consider soft. Tonal density is a weaker point of the 845 and a strength of the wa33, it’s going to be richer overall where the 845 will sound a bit more dry in comparison.
Oh what the hell I’ll just be lazy and do it this way (to be clear this is with the elite not reg)
Macrodetail/Surface Level Detail : Woo >= Viva (Viva is very clear in conveying things up front but the woo does that slightly better without calling as much attention to itself)
Microdetail/Low Level Detail : Woo > Viva (Woo can just pull more from the recording here)
Speed : Viva > Woo (Viva has crazy speed)
Separation : Viva >= Woo (Viva more separated although slightly more artificially than the woo)
Control & Grip : Viva > Woo (I do think the viva has heavier handed control over everything)
Impact & Slam : Viva > Woo (I do feel that the viva is less rounded and more punchy and more substantial sounding when things hit)
Midrange Texture : Woo > Viva (Woo can really pull a lot of texture quite well)
Bass Texture : Woo >= Viva (The viva is close but doesn’t quite pull as much or present it as well as the woo)
Treble Extension : Viva >= Woo (Viva feels like it goes a bit farther, although woo is more refined)
Bass Extension : Viva >= Woo (See above)
Microdynamics : Woo > Viva (The woo has a stronger focus on lower level volume changes)
Macrodynamics : Viva >= Woo (Woo almost there but can’t quite match the large swings the viva can pull off)
Background Blackness : Woo > Viva (Woo sounds more spatially absent)
Stage Width : Viva >> Woo (Viva just goes a whole lot farther and grander)
Stage Depth : Woo >= Viva (Woo can go a bit deeper but honestly the viva is still more impressive to me since it’s able to almost get there with a much more substantial stage size)
Stage Verticality : Viva >> Woo (Viva feels more holographic and involving here)
Stage Boundary : Woo >= Viva (Woo is more tightly defined and composed in stage)
Placement Accuracy : Woo > Viva (Woo feels more natural and realistic in placement)
Presentation Organicness : Woo >> Viva (See above)
Presentation Openness : Viva > Woo (Viva just feels more open and airy from a stage perspective)
Timbre : Woo >> Viva (Woo just does really well here, it’s presented more inorganically on the viva imo)
Tonality Organicness : Woo >> Viva (The woo leans more neutral but a very coherent and well weighted neutral, with tube swaps it can lean cleaner or a bit more warmth but still generally more balanced and convincing)
Tonal Density Quantity : Woo >> Viva (Woo just has more meat on the bone)
Tonal Density Quality : Woo > Viva (More accurate, viva not bad here though)
Smoothness : Woo >> Viva (Woo has better overall smoothness for sure)
Softness/Roundness : Woo >> Viva (The viva is a harder edged sound without getting harsh, woo def has a more roundness)
Liquidity : Woo > Viva (Woo feels more effortless overall)
Coherency : Woo >> Viva (Viva has some issues with slight midrange disjointedness and it’s more exaggerated aspects don’t help it here either, woo feels very complete)
Forwardness : Viva > Woo (Neither offensively forward but the viva is more in your face about things)
Energy & Incisiveness : Viva >> Woo (The viva offers a level of energy and directness that you just don’t get from the woo)
Forgivingness : Woo > Viva (Neither are all that forgiving but the woo is kinder to lesser sources and music)
Overall Treble : Woo >= Viva (While I think the viva is more extended and linear, I don’t think it’s as refined and nuanced as the woo treble)
Overall Midrange : Woo >> Viva (midrange is weird on the viva, it’s both rounded and sweet but overly technical, I really should change this but I think the midrange of the woo sounds more mature, that somewhat lack of coherency put me off from the viva when it came to midrange)
Overall Bass : Viva = Woo (While the woo is more organic here, I can’t help but love the amount of energy and control the viva has in the low end)
Overall Subbass : Viva > Woo (This one really is the viva doing quite well where the woo is just more polite and restrained here in comparison, but both still really good to be clear)
Basically, if you like stage, energy, explosiveness, and a more forward and in your face sound, go 845. If you like something a bit more composed, nuanced, refined, and balanced, go wa33
I will say the egoista is a bigger pain in the ass, it’s more expensive to tube roll (potentially, for the 845 at least), it’s less safe since you can somewhat easily blow your headphones if you aren’t careful when turning it on, runs hotter, and is more picky what goes into and out of it. But I don’t think that’s enough to put people off from wanting one, just something to note. Neither of the amps are what I’d consider low maintenance but the wa33 is more plug and play.
DAC wise running the bricasti, the m21 paired well with both, although I slightly preferred the viva pairing since it made the amp more composed and addressed some of the complaints about coherency and exaggratedness, added a bit more weight, and reduced intensity a bit without taking out what I liked about the amp. With the woo it’s good but more neutral and no nonsense, but no complaints with that pairing
I think generally I personally preferred the susvara with the wa33 elite and the 1266 with the 845, but that’s more if I wanted to double down on what the cans are good at, if I wanted to more try and compensate for what they didn’t have it would be the opposite, they were good on both but I really like the susvara on the wa33 for it’s nuance and refinement because they both do that well, and the 1266 on the 845 for it’s stage, energy, and directness because that’s what they both do well
I did own the 845 a lot longer than the wa33 elite if that says anything, but that’s likely because the 845 fit a better niche role in my collection of amps at the time where the wa33 was more an all rounder and I didn’t feel I needed that with what else I had on hand. Both top tier amps though
In terms of getting ahold of one, you are much more likely to find wa33 than you are 845 in the us, although 845 are actually a better value if you can find one since they drop more in value on the used market, but international shipping could quickly diminish that potential extra value
Tube wise, I do think there’s more tweak ability within the wa33 than there is the 845, the 845 is more something you pick and forget and the wa33 can be more subtly tweaked easily, responds better to different tube swaps, and there’s just more options for what you can swap in there for sure if you are that sort of person, but I’m not, I’ll just pick something I like and go with it