Recommended Components 2023 Edition Signal Processors & Computer Software

Signal Processors:


Chord Hugo M Scaler: $5650
The Chord Hugo M Scaler is a digital processor but not a digital-to-analog processor, its purpose being the upsampling—referred to in the UK as upscaling—of incoming data. When connected to a Chord DAC via BNC connectors, the M Scaler can upsample up to 705.6kHz or 768kHz, but with non-Chord DACs the upper limits become 176.4kHz and 192kHz. (In all cases, incoming DSD data is converted to PCM, with a 6dB reduction in level.) JA used the M Scaler with Chord's DAVE D/A processor, and with his own PS Audio and Mark Levinson DACs. In all cases, but especially with the DAVE, upsampling via the M Scaler offered such improvements as "more image depth, an increased sense of drive, and even more clarity." That said, owing to the fact that the M Scaler is "relatively expensive," JA recommends auditioning it with your DAC of choice "before getting out the credit card." (Vol.43 No.3 WWW)


Accuphase DG-68 Digital Voicing Equalizer: $24,000
See "Digital Processors."

AudioPraise VanityPRO HDMI audio extractor: $1599
The VanityPRO extracts a digital audio signal from the HDMI stream and offers several options for processing and outputting the extracted audio for playback on a high-quality audio system. KR appreciated the opportunity to apply DSP, channel-level adjustments, active crossovers, and room correction while playing discs, without redundant D/A–A/D conversion. "It's a pleasure to run DiracLive—to balance channels and compensate for room acoustics—not just with files but also while playing discs," he wrote. KR's review sample was fitted with four AES3 (XLR) stereo outputs supporting up to eight channels of audio. The multichannel version is also available with four electrical S/PDIF outputs with either RCA or BNC connectors. The stereo version, which costs the same, comes with AES3, S/PDIF over RCA, and TosLink—one of each. (Vol.45 No.5 WWW)

GeerFab Audio D.BOB: $999
"This unique device is a solution to a problem that previously couldn't be solved," wrote KR. The GeerFab D.BOB digital breakout box takes a universal player's HDMI output and with SACDs, extracts two-channel DSD data from the HDMI audio stream, and outputs DoP (DSD-over-PCM) via RCA and TosLink S/PDIF connectors. GeerFab assures users that this implementation is both legal and compatible with HDMI 1.4b and HDCP 1.4. JA's measurements confirmed that the D.BOB's output was bit-perfect—ie, the bits it outputs via S/PDIF are the same as those sent to it via HDMI. (Vol.43 No.5 WWW)


Denafrips Gaia D/D reclocker: $1820
The Gaia takes in digital signals through its USB, S/PDIF (including optical TosLink and RCA electrical), or AES3 inputs, buffers them, and reclocks them with the same OCXO clock used in the Terminator Plus. Perhaps because of this similarity, HR found that the Gaia gave only a small improvement when used with the Terminator Plus: "The Gaia's positive effect on the density and clarity of sound ... was smaller and less music-enhancing than I expected." With the Gaia inserted (USB in, coax out) between his Roon Nucleus+ and the Terminator Plus, he wrote that "clean and resolved" became a tiny bit more "grainless and sanitary." But that was all. (Vol.45 No.5 WWW)

Nordost Qnet Network Switch: $3199.99
The QNet is a layer-2 Ethernet switch with, Nordost says, "five ports designed from the ground up with high-end audio performance and an extremely low noise operation in mind." JVS initially used the supplied 9V, switch-mode wall wart with the QNet, but then substituted the optional QSource power supply. JVS summed up his experience of the QSource-powered QNet, both of which he subsequently purchased, by writing "I'll simply say that it is now much easier to follow each line in even the most complex passages of Mahler or Strauss and to understand, musically, the reasons behind the complexity. Thunderous organ now resonates strongly, without inappropriate boom. Tonal color inside my music room is beyond acid-rush intensity." (Vol.45 No.10 WWW)

Computer Software:

Channel D Pure Music software: $129 ★
Pure Music (Mac only) can play sampling rates of up to twice the 192kHz limit of Amarra and Decibel. Like those programs, Pure Music (Mac only) offers memory play, automatic sampling-rate changes, and full compatibility with native FLAC files and in its latest version, DSD files. Going from iTunes to Pure Music, the sonic improvement was modest but worthwhile, with cleaner trebles and improved pitch certainty. Compared with the less expensive Decibel, however, Pure Music lacked some openness and clarity, decided AD. Using Pure Music in its Memory Play and "Hog Mode" settings for optimal sound quality resulted in a wider soundstage and greater sense of ease, said JA. A free, 15-day trial version can be downloaded from Included with Channel D's Pure Vinyl Version 3.0. (Vol.33 No.8, Vol.34 Nos.7 & 9 WWW)

Channel D Pure Vinyl LP ripping software: $379 ★
Used with a microphone preamp or non-RIAA phono preamp, Channel D's Pure Vinyl digitizes vinyl LPs at 24-bit/192kHz resolution and applies the RIAA or other EQ curves in the digital domain, where there's no interchannel phase shift, capacitor distortion, additional noise, or component variability. Record mode allows the user to apply over 50 EQ curves or create custom EQ settings; Editor mode allows the user to insert track breaks or remove surface noise. CDs made with Pure Vinyl sounded "much better" than those made with the Alesis Masterlink, said MF. Compared to the original LPs, the digitized versions lacked a touch of body but sounded "very analog-like." Compatible only with Apple Macintosh computers. Version 3.0 and later includes Channel D's Pure Music front-end program for iTunes. "Pure Vinyl will change the musical lives of collectors with large collections of pre-1954 discs," said MF. JA was impressed by Version 5's RIAA de-emphasis with LPs that had been ripped with the Channel D Seta L phono preamp's Flat outputs. (Ver.5 was not yet compatible with macOS 15/Catalina in the fall of 2020.) Channel D's Rob Robinson strongly advises recording at 192kHz—"Pure Vinyl was designed and optimized with that sample rate in mind (back in 2003!)" he told JA—but for monitoring the recording in real time, the playback D/A converter must be sample-synchronous with the A/D converter. (Robinson recommends the Lynx HiLo, an MF fave, for that reason.) "To say that I was impressed with the quality afforded needle drops by Pure Vinyl would be an understatement," concluded JA. "While the user interface is not as intuitive as I would like, the versatility on offer is extraordinary." (Vol.32 No.3; Ver.3.0, Vol.33 No.8; Ver.5, Vol.43 No.11 WWW)

Dirac Live 3 room-correction software: $349 stereo license, $499 multichannel license ★
Sound quality, of course, is dependent on the hardware in the system, wrote KR, about the original Dirac Live, an app that runs without external processors on Macs or PCs. But its acoustic transformation capabilities are well beyond what is built into most processors, he wrote. Live 3 allows the user to measure the system's in-room response, then generates the necessary correction filters. The Dirac Live Processor then applies the filter corrections to music as it plays. In PCs (Windows 10 and above) and Macs, it can be installed as a plug-in or as a regular application. JRiver, Audirvana Studio, Amarra, and most DAWs support it as a plug-in. Roon does not. KR continued his recommendation for the app, writing that with Dirac "I hear no loss of transparency; rather, I hear more transparency due to the removal of distracting artifacts." Live 3 also includes Dirac Live Bass Control, which KR tried in beta form. He found that "Full Bass Optimisation resulted in much better integration of the subs with each other and with the main speakers—to the point where the subs disappeared but the main speakers seemed to have prodigious low-frequency extension and control." (Vol.37 No.5, Vol.44 No.10 WWW; also see JA's discussion of Dirac Live LE in his review of the NAD M10 integrated amplifier in Vol.43 No.1 WWW)

JRiver Media Center: $59.98 (single platform); $79.98 (multi-platform)
KR wrote in the January 2018 Stereophile: "If your [JRiver Media Center] setup is working to your satisfaction, there's no need for you to download every new build." Really. No need at all. But, having said that, . . . the 64-bit Windows version of Music Center became available in September 2017, and KR reported that it's better, stronger, and faster than the 32-bit version: "Since installing the 64-bit version of JRiver Music Center 23, I have heard not a single burp." $79.98 for a "Master" License covering Linux, Windows, and MacOS. (Vol.41 No.1 WWW)

Roon Labs v 2.0: $14.99/month, $149.88/year, $829.99/lifetime
Roon is a cloud-based music-playback application that can be downloaded and run on the user's desktop or handheld computer or run on dedicated file players from manufacturers including Auralic, dCS, Linn, and others. Described by JI as "a tour de force of programming, design, and metadata mining," Roon offers a graphically sophisticated user interface that, he said, looks good and feels natural. When first installed, Roon scans and incorporates the user's existing music collection. Over time, it continues to "groom" that collection, taking into account new additions to the collection and to Roon Labs' ever-growing library of metadata. With v1.8, Roon offered a major revision. "Visually, it's new, and to me, better," wrote JCA. The recommendations engine, Valence, has been improved, with useful changes to the Focus feature, which now encompasses streamed music from Tidal and Qobuz—not just music in the user's library. "The music I own and the music I rent is now one big, searchable, browsable library," enthused JCA. JA is also a fan and sprung for the lifetime subscription. (Vol.44 No.5 WWW)

JRT's picture

The listing includes, "Topping Pre90: $599 plus $249 for the Ext90 input extender"

Topping's more recent A90 Discrete, aka A90D ($599) seems to include similar preamplifier functionality as the Pre90 at the same price, including the relay switched R-2R attenuator, and facility to add the Ext90 ($249) input extender. However the A90D also includes a headphone amplifier, which is not included in the Pre90, and the A90D uses discrete electronics in the audio amplifiers.

I am suggesting that the A90D might be a good subject for future review; and in the review bundle, it might be worthwhile to also request the aforementioned Ext90, the D90SE ($899) DA converter, and the SR2 ($219) modular three shelf aluminum component rack, which has suitable geometry, is designed for use with these components.

This isn't SPAM. I have no financial interest in this, have no affiliation with Topping or any of the vendors. I was merely considering updating my old home office setup, maybe.

Indydan's picture

Can Stereophile please remove all MQA enabled equipment from the recommended list?

mieswall's picture

Well Torquemada, why so shy?
Along with those A+ sinners of BelCanto's, CH Precision, dcs, EMM Labs (average cost of the heretics close to US$31,000), and also those more modest but equal sinners of GoldNote, IFI, Meitner, Sonnet, etc; why don't we also include Bob Stuart and Peter Craven in the bonfire and joyfully watch them burn? We should also declare Michael Gerzon a black angel (after all, most of MQA ideas were conceived by this AIA Gold Medalist devil).
And beware Fremer, Serinus, Austin (and every other one suggesting the earth isn't flat, btw): Don't you dare praising MQA again! We are watching you!

Kal Rubinson's picture

Why? I think people who want it and those who don't are equally well served by the information.

(Posted by someone in the latter group.)

miguelito's picture

Devices supporting MQA also support most other standards - I don't see a reason to remove them. Also, I have some MQA albums (some white-glove albums were done extremely well) so I want to be able to play those going forward.

JRT's picture

I noticed that the front page does not list the annual Recommended Components articles in the footer. I think that adding that listing or adding a single link in the footer to a page loaded with a collection of links to those annual articles might attract more page views.