I've had 2 pair of Music Purifiers in my bi-wired pair of Eminent Technology LFT-VIIIB's for a couple of months now.
I liked what I heard when I first put them in, more spacious, sound sources were better defined and separate. BUT like the OP (Bobfitz1), I find the best way to evaluate a change is to revert back after I have gotten used to the new sonics.
What I heard when I disconnected the Music Purifiers was a more diffuse and less specific sound-field that had many of the sounds anchored on the speakers. The level separation and definition I had come to treasure had dropped. Music became less enjoyable and less engaging.
Reconnecting them immediately brought back the benefits.
When I say separation and definition, one thing that I listen for and that brings enjoyment to me is hearing the inner detailing of the interplay of notes, how they are played/sung, and emphasized/synced with the other instruments/singers, melodically, harmonically, and temporally. This increases my emotional connection with the music and the intention of the musicians. When these subtle details are audible, I often lose myself in the music listening to their artistry, as I did last night when I only intended to have the setup on 15-20 minutes while preparing to audition some upgrades... and stayed to listen for another couple hours.
I know everyone here has had seminal audio experiences, like my 1st time hearing a setup with then-high-end pretentions back in the late 1970s... a well-regarded Kenwood table with a Black Widow arm hosting a top Grado, Apt-Holman preamp feeding an Audio Research tube amp, and a pair of LS3/5As. I never knew a stereo could sound so good. What I heard started me down my audiophile path.
Another was at a mid-80s Chicago CES... Pink Triangle turntable with a Kiseki Blue, Rowland pre and amp (it was their room), and the fabled, beautiful, and rare Xstatic speakers. The sax on track 2 of Bernie Krause's Citadels of Mystery, "Heights of Machu Picchu" was the first time that reproduced music brought tears to my eyes. AND that launched me on a search to bring that to my system, which I only realized when I added tubes into the mix.
BUT the one that I was reminded of while I was listening to my setup with the Music Purifiers was during a tour of Audio Research back when I lived in Minneapolis. The local audio society arranged an annual tour of either ARC or Magnepan (with Wadia thrown in the mix those years when it was active nearby). While what I heard in the ARC listening room on my 1st tour was impressive, it did not compare to the 2nd tour a couple years later. I forget the turntable and cartridge but remember the Magnepan Unitrac arm and the Warren Gehl platter mat, IMHO one of the best ever. ARC electronics and cables of course, an SP-11 and a pair of M300's as I remember. Speakers were a pair of the then-fairly-new Infinity IRS Betas. They played "Mean Daddy Green" from Radka Toneff's Fairytales album. Beautiful. BUT what struck me after I listened to most of the piece was that I was hearing how she physically sang... the final phrase of the piece are the words "Mean Daddy Green" and I heard how she opened her mouth, held her lips, and moved her tongue. WOW!
I've worked to gain that level of insight into the music since then, in the mid-1990s. While I have had glimpses of it, the Music Purifiers made it gell. AND not only on well-recorded Audiophile recordings, but on many mass-market jazz, pop, and classical recordings too.
That setup (I have 2)... DIY'd digital front end with bits from Allo.com, Ian Canada, and Uptone Audio, with the endpoint and DAC powered off the grid via a massive amount of Ultracaps (~20,000F!) and batteries. S&B TX102 transformer volume control. PS Audio BHK-250 Amp and P15 AC Regenerator. MIT MI-330 Shotgun and MH-750 cables. Eminent Technology LFT-VIIIB speakers. And lots and lots of tweaks.
Finally, I've been both a customer and a follower of Ric at EVS since the early 2000s. Have purchased several of his amps and modified DVD players and used techniques from those and what he shares online (and privately) along with purchasing various bits from him, like that S&B TX102, in my own DIY efforts.
Thanks Ric!
Greg in Mississippi