SS Amp Upgrade Thoughts (from Simaudio) with Magicos

Sorry, I wasn’t paying enough attention,

you listen lower than I realized 50-75db, and I see your existing amp is more power than I guessed simply because you asked the question. existing 125 wpc/8 ohms; 250 wpc 4 ohms, speakers 88 db, btw the existing amp’s specs say it is only 14" deep. 

@onhwy61 is probably correct that you need some bass boost at those low listening levels, with ANY AMP, as it is our/your/everyone’s ears that do not hear linearly at low volumes.

https://en.wikipedia.org/wiki/Equal-loudness_contour

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This Chase RLC-1 Remote Line Controller adds remote control, and can solve low volume listening with it’s built-in automatic and progressive bass boost as you lower it’s volume below it’s default level. no bass adjustment as you raise your volume. You need the remote, no controls exist on the unit.

https://www.ebay.com/itm/116746487231?mkrid=711-53200-19255-0&campid=5338381866&toolid=10001&customid=15eba7a8-de88-11f0-8ced-353039373734

I have used them in all my systems for many years, primarily remote power on/volume/balance/mute, either directly or thru a tape loop which is how I know that nobody can tell if it is in or out of the system, it simply does it’s job undetected.

I  think you have a nice set up already, but shopping sure is fun!  I also recommend the Coda amps, but would not consider the Benchmarks and upgrade at all.  Moving up the Moon line would surely be an upgrade if it would fit.  (come on honey, its only a few inches' :).  Audionet Max amps would be a big upgrade, maybe finding a spot down low or on the floor next to the rack.  Used they are a huge value.  Good Luck!

"Perhaps a bit more slam, transient speed. While the base is tight and precise, could possibly be a bit fuller.  (No room to have a sub.)"

I have the A3's powered by Hegel H20, only have heard them with a Conrad Johnson MF2250 and a McCormick amp forget the model and picked the Hegel.

Given your slam + transient speed goals I'll throw out the a Swiss Digital fuse box with the graphene sluggo on your current amp. Cost around $500 they have a money back guarantee. You could put that earmarked money somewhere else in the chain. Just mudding the waters with alternate paths.

Could you cut out the back of the cabinet to accommodate a larger sized amp?  Thst would open the door for endless possibilities. 

Looking at the OP VS I would say his issues are room and setup related. Throwing money at the problem will not fix it, get your setup right. 

Also if you are throwing money at it, then get another 330a and run them in Mono.