I actually listened to all three filters in two different systems. The main system uses an optically isolated network consisting of SOtM switches and Nordost V2 network cables to hook up the Wadax Reference Serve/PSU to the Reference DAC, via its dedicated Akasa Optical interface. The second system also employed a dedicated, optically isolated network, this time built with a Roon Nucleus (with linear power supply), an EE 8 Switch and Nordost Heimdall 2 network cables, linked to the Ethernet-HD input of the CH Precision C1.2. Source for streamed files was Qobuz. However, in practice the results were remarkably consistent across both set ups, despite the cost and qualitative differences, perhaps suggesting the fundamental level at which these filters operate.
Good – The English Electric EE1 Network Filter
Offered by the Chord Company’s sister English Electric brand, this is about as simple as a Network filter gets, a directional, matchbox-volume block with an RJ45 socket on each end. It was supplied with a Chord Co. C-Stream network cable to hook it up to the system, although I used Nordost V2 or Heimdall 2 network cables to maintain continuity from the main switch onwards. Following conventional logic (and only having a single unit to hand) I placed it adjacent to the Ref Server or C1.2 ethernet inputs, connected with a 1.0m length of the appropriate cable. Compared to the unfiltered feed, the benefits were obvious, with an immediate reduction in grain, a blacker background, an increase in stage depth and an emerging sense of musical and rhythmic order: In comparison, the unfiltered feed sounded flat, grey, grainy and cardboard-y, with a fractured and disjointed sense of rhythm and flattened dynamics. Inserting the EE1 certainly cleaned up the presentation and delivered worthwhile improvements in the musical bedrocks of rhythmic and temporal security – areas in which streamed music seriously suffers.
The filter’s sonic benefits were clear enough but it was the greater sense of musical connection, the fact that the different musical strands were starting to hang together and make more sense that was what made the EE1 a compelling addition to the system. One that once inserted, I was loath to remove. The Anastasia Kobekina album Venice (a 24/96 file from Qobuz) contains the short, percussive/pizzicato piece ‘Limestone & Felt’, by the brilliant Caroline Shaw. Streamed au naturelle, the jagged phrases and halting rhythms fall randomly from the speakers, a jumble of disconnected noises that lacks shape, intent or line. The dynamics are flattened to the point that there is no distinction in attack or weight between notes, no sense of accent or purpose to the phrasing – what phrasing is apparent! The EE1 not only adds body and colour to the solo cello, it introduces a sense of musical flow and progress, driven by the ability to differentiate note weight and attack, to separate more readily the plucked strings and the struck body of the instrument. Elsewhere, group compositions gained a greater sense of ensemble organisation and instruments took on a greater sense of presence, especially harpsichord, which had been little short of irritating with the un-filtered stream. Without the EE1, the performance was ‘loud’ and clumsy, lacking any sense of the musicians’ touch or selection of note weight. Subtle dynamic variations and timing cues, harmonics and note length were all eradicated, fitting the music into an almost mechanical grid, effectively ‘pixelating’ the textures, perspective and instrumental detail.