I've had my Waxwing for about a week now, and I must say that this little device is astonishing. Its capabilities are wide-ranging and useful, the form factor is nice, and the app control is amazingly granular yet easy to use. There are SO many ways to tweak things! I've been doing some A/B comparisons with my Cambridge Audio Alva Duo, with no extra processing engaged on the Waxwing - it's running on factory defaults.
These are both *excellent* sounding phono preamps, there's no doubt about it. The Alva has a slightly more expansive soundstage, but just ever so slightly. The Waxwings real strength is that it's SO adjustable, and I need to dedicate some time to sitting down and playing around with all of its functionality. One feature I'm already completely in love with is the Logging function, which keeps track of the time you're playing music (and adding wear to your cartridge/stylus) automatically. This thing is literally a Swiss army knife for vinyl playback. You really get a HELLUVA lot for $500 IMO.
My gear chain is: Rega P6 with ND5 -> Alva Duo/Waxwing -> Yamaha RX-A8A AVR -> Onix Rocket RS750 speakers + SVS PB12 NSD sub.
I was wondering if I even needed a phono preamp for my Denon 6800 7.4.4 system so I bought a Fosi X5 cheap, highly rated here. No real loss of no improvement. It was a big improvement, then like you I want with the Cambridge Audio Alva Duo (2 actually for upstairs and downstairs systems. Liked it a bit better, lower noise floor, when cranked no hiss like the X5 (which was audible but mostly on dead wax, no big deal). Then I went with a Waxwing, then a second Waxwing.
It's great, endgame, I use it to adjust sound to taste, some LP's are iffy even if new, mass produced in huge numbers, often a lack of Bass compared to the CD or just a high pitched mess, I have found "Air" and "Warmth" to improve poorly masters albums, often to damn near audiophile standards (to my ears).
One hint, AIR and WARMTH seem to be opposites in what they do. When I used to add Warmth a few notches I often had the peaking indicator appear often.
To prevent peaking, if you want WARMTH, take AIR down, not WARMTH up, and the opposite for AIR, want that extra detail, take WARMTH down, not AIR up. Of course do what sounds good to you but I found when I raised a few things a bit, like Warmth and bass a few notches, the line clips faster. I have also have avoided clipping by raising WARMTH 1 notch and lower AIR one notch. (Keeping a balance of not raising all things and overloading the line.
MAIN SYSTEM Project RPM5 Ortophon LVB250 Black
UPSTAIRS SYSTEM Project Carbon EVO with many upgrades and Ortophon LVB250 Black