Where on the broad axis of snooze, shudder or shazam would AA fall? The ~$25 MeanWell GE24I12-P1J switching power adapter from Taiwan certainly seemed declassé in today's $2K context. But since it was chosen by a company that works in EMI reduction not intensification, snooty perception will shudder before it must bend. A bit odd given obvious care to craft a sleek case were plastic foils covering its top and bottom. Unsure whether these were thoughtful transit protection or meant to stay on, "we use adhesive film to protect our screws from backing out. The filters have plates on both sides so we use a shiny top label. That's not required for any functional purpose although the bottom label with its regulatory imprint should stay on for customs purposes. I’d rather you not take the plates off because the screws are pretty delicate and can sheer off quite unreasonably. I could show you the insides but prefer that you'd not publish my pictures. They'd be no more interesting than the close-up I already sent." So I left the shiny foils on though the one on top looked cheap as though someone forgot to peel off protective film. The bottom label identified the RJ45 adjacent to the DC inlet as the input which is also where the three LED sit. As soon as I wired AA into my iMac feed, the power LED went red and the i/o speed indicators blinked dark blue to show 1GBit transfer rates. That's what my fibre-optic high-speed contract pays for. It was good to see it confirmed. I was ready to shadowbox in the subtle realms. With AA as shown at the tail end of the 2nd LAN distributor, my math-challenged mind figured that if the two LHY switches in series already attenuate my Ethernet noise to below all audible run-on effects, AA couldn't do a thing because there was nothing left to do. If I then bypassed the switches and just left in the AA whilst the sound didn't change, I'd count the DJM filter solo as effective as my LHY combo which requires extra CAT wiring plus two classic power cords. That'd equate to the same result for more money with less complexity but fewer features. The perhaps best-case scenario would still milk some cumulative effect whereby all electrical filters leak something so subsequent filters still manage to make a difference, albeit ever smaller. Against these mental scenarios, what did reality have to say?

Ethernet in, USB 4TB SSD in, USB Apple Drive in, USB Curious Cable out to Singxer SU-6 USB bridge. LessLoss AC cord on iMac, itself in Puritan Audio Labs power conditioner as were the two LAN distributors and AA.

As so often, reality had its own mind. Comparing AA to LHY² had the former decidedly more lit up and leading-edge energetic across the board. The network switches played it darker and chewier. Cavalier but common parlance would claim digital versus analogue. Both were effective in their own ways which full bypass of router ⇒ iMac proved. But whatever this lot did was certainly far from the same. Even Joe Sixpack from the pub would have registered the difference. It wasn't subtle.

Attempting a virtual chocolate/vanilla swirl worked, too. For that I added AA to the LHY twins. Without reverting to its solo showing as though the network switches stood their ground quite firmly, the AA addition injected a bit of perkiness and illumination atop the LHY tuning. In terms of delta, the doubled-up switches were more effective or at least 'other' when compared to the flatter, edgier, grainier more two-dimensional router-direct mode. AA also fleshed that out and deburred it but didn't apply any darkening or mellowing. That action was the provenance of the LAN distributors.

Because their contribution countered the direct connection, I called it more effective or at least 'other'. AA didn't change the brighter lights of going router-direct. It just removed grain like a degritter and eliminated the lean/flat taste. It got dimensionally more complex and for that fuller but didn't alter the perceived lighting. The LHY duo played with the lighting which as usual influenced my perception of musical pace. To me darker and heavier feel more relaxed whilst lighter and brighter translate into more drive, charge or immediacy.

Ditto the nearfield vs mid/farfield effect. Close to stage is more percussive and lean. Rear of hall is more legato and bloomy. Test gear has no such responses. Graphs show no direct correlation. Our ear/brain makes multi-layered associations between our different senses. Microphones only listen; and do so without brain interpolation.

Given the different results, it's fair to reiterate that DJM's Activ Audio filter attacks EMI via proprietary DSP whilst the LHY network switches reclock. Different jobs, different effects? I use question marks because this stuff is well above my paygrade. I approach it like a pragmatic hedonist. Whatever it does and however it does that, can I hear a difference? If so, do I fancy it? I needn't know more. Do you? If so, you've come to the wrong place. You need to talk to digital, network, audio and electromagnetic compliance engineers. I imagine they'd squabble quite a bit. Back on personal hedonism, if I could only have my LHY switches or the DJM, which would I choose? The switches. That's because they make my cloud-file playback virtually indistinguishable from local files which themselves were judged against then mollycoddled for parity with CDs spun off a dedicated top-loading transport. But since hedonism is all about self gratification, if cost was no object, I'd leave the DJM between the slaved switches and iMac's Ethernet input. That'd be my LAN ice cream swirl. To conclude, this filter grows quite warm to the touch. Whatever processing ticks away inside must be quite intense. It looks far nicer than photos of the original version but also nearly quadruples the ask. In fact, $1'950 seem stiff against the LHY Audio network switches. If DJM plan on costlier dealer representation, it all makes sense. If their main focus is to sell factory direct, savvy shoppers might not view this filter as very good value. That simply doesn't negate that it works; and probably better/stronger than I know because our very rural location doesn't strike me as a hotbed for EMI pollution. Audiophiles in big cities should deal with far more radiation. Common sense suggests that filtering industrial electrosmog and stacks of overlapping WiFi pollution by a whopping 100dB ought to increase the before/after delta over what I experienced. And already that was far from imaginary…