Products you added to your system in 2021 that made most impact to your music enjoyment

Big upgrade year for me on multiple counts: 

Went from Rogue RP-1 to and RP-7. The level of quiet this piece is and the musicality when it's making sound are incredible. Have changed to some NOS tubes that have made it even better too, currently running amperex bugle boys in the front with Mazdas in the rear.

Analog front end got a major upgrade from clearaudio performance DC with tracer tonearm and Hana 1200 (no slouch) to brinkmann bardo with 10.5 arm and ortofon cadenza black. Whoa. The detail retrieval, channel separation, and frequency response are nuts. 

Also on the analog side went from musical surroundings nova iii to a Rogers High Fidelity PA-2. Incredible Soundstage and clarity. The airy-ness is hard to beat. I feel like I cam hear the room things were recorded in. 

Additional tweaks that get some props are herbies audio lab tube dampers, tenderfeet, and supersonic stabilizers really quieted down the Rogers even more.

This was the year of complete change from a system we thought was wonderful and had been in place for decades. We retired and sold the vintage Technics SL-120 with its Mayware-Polk Audio arm and Micro Accustics 2002 cartridge. No more LPs. We sold the HK Citation 11 that had been in our closet for 10 years. We replaced the 45 year-old Quad 405 amp and Parasound Zpre2 with an Audio Note Cobra integrated to run our Quad ESL-57s. We purchased a custom made-to-measure digital cable from the Jolida JD100 CD player so we can use the Cobra's MUCH better DAC. (We will replace the Jolida for a CD transport next year.) Then purchased custom made-to-measure Audio Note Lexus LS speaker cables with banana plugs. Finally, because of our unpredictable electric grid, we purchased a Dectet AC Power Conditioner and their hospital-grade electric outlet. The result? With every addition over this year, not just small increments, but dramatic improvements were experienced. We now have a system that is a total joy to listen to and will probably last us a few more decades. Who knew? The only thing we didn't replace was our 47 year-old Quad ESL-57s. For us and the music we listen to, there are no better speakers. This has been a VERY good year.

Purchased 2 SVS subs.  Great addition!  Added sound absorbing panels to a wall.  Another great addition!  All learned from reading various threads on this site!  I'm always learning and experimenting, even at 66 years old!

I totally agree with the original poster acoustic Zen cables don't get the respect they deserve any more on here, and I don't know why you didn't try the acoustic Zen speaker cables cuz they're just as good as the audience but a lot cheaper single-crystal is single Crystal just some companies charge more for it but OCC single crystal wire is the best wire for audio and it's been proven for 40 years now

Added a REL T7x to my system---much more depth and punch. Highly recommended.