everything sounded great until the upgrade

A different point of view. There is an old review out there comparing the A3.2 to the former MF A300, and reviewers indicated something that reminds me of how a 2252B will sound warmer closer to an MF A300. However there is praise the A3.2 brings to the equation. As others shared here, give it a few weeks, keep listening, give yourself a chance with the A3.2. If you plugged it in cold after sitting a while, let it play 10-14 days. Also comments the A3.2 reveals what you throw at it, hearing more of bad recordings too. Some of the older 2252Bs can be a veiled over sound. Or, the ones I've heard with original transistors still in them that is. 

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Article/quote: "A3.2 has that sense of harmonic ease, but the A300 is a touch more full than the A3.2. The newer A3.2 integrated has at least as much bass, but seems to control it a bit better. The end result of this is that the A3.2 sounds a bit leaner, but more in charge of the speakers. Throughout the midrange the A3.2 has a leaner tonal balance. Where the A300 is slightly warmer through the mids and can thus sound a touch laid-back, the A3.2 has a more up-front perspective. This isn’t to say that it’s bright or aggressive -- it’s not -- but rather that it’s a bit more incisive".

@decooney 

The reviewer you quote describes the A3.2 as I remember it.  I thought the A3.2 was on the leaner side of the spectrum, not warmer.

No matter how it sounds now, take decooney's good advice and give it a chance to warm up thoroughly before making any decisions, I'm thinking it will really grow on you.

@decooney 

that's pretty accurate. My initial thought was that it's unforgiving, highlights all the errors the 2252b hides/unable to reveal

I can't speak about the A300 but I have two friends with A3.2s, one with Maggie 1.6s and the other with Martin Logan Requests. I spent a lot of time listening and improving those systems. Both were in very good rooms and both sounded very good. I think the A3.2 can play well with some proper set-up. Give it time and good speaker placement. 

If you have changed the balance of your system, you can try to compensate by doing simple things, like experimenting with speaker or listening chair placement, minor acoustic treatment, like putting tapestries on the walls or using an area rug on the floor (things that may not cost much or unduly disrupt your life).  Doing more to compensate, like buying different cables is a gamble because it may not work.  I hope it is something like changing the toe-in of the speakers that will do the trick.

sometimes just getting familiar with the new sound will also change your mind, so be patient and go slow with the changes.

I can understand your not wanting to fully disclose the products involved, but perhaps you can say what were the components that you liked before the change.