Solid State Preamp Reviews

Hygge might not be the first word that comes to mind when contemplating the Primare PRE35 Prisma preamplifier, but in Limhamn, Sweden, that is how Primare likes to describe their products. It means "cozy," and it's a very important concept in the Nordic countries, almost a way of life. Another term that appears in Primare's product descriptions is lagom, which loosely translates as "not too little, not too much—just right."

For me, none of this is lost in translation. I'm all for folksy adjectives for high-tech equipment. After spending hygge time with the new PRE35 Prisma preamplifier, I've come to equate hygge with "not digital-sounding" and lagom with the elegance of its physical and electronic design: not too little, not too much.

By modern hi-fi standards, Primare has been in business for a while. Founded in Sweden in 1985 by Bo Christensen and Bent Nielsen, Primare takes a team approach to research and development: Specialists work on different technical aspects of their designs, then Nielsen, Primare's chief engineer, pulls everything together. Primare was an early adopter of class-D amplification; my colleagues Kal Rubinson and Herb Reichert have both explored this aspect in recent reviews of Primare amplifiers (footnote 1). Primare is also known for being ahead of the game in exploring digital audio storage and streaming technology, capabilities fully implemented in the PRE35 Prisma.

In recent years, with an ever-increasing variety and quality of integrated components on the market, and the rising cost of interconnects, even die-hard "separatists" are giving them a look. Primare's lineup includes 21 components, most with some degree of integration. The advent of ancillary modules has rendered the notion—and price—of stand-alone components somewhat fluid: The PRE35 Prisma preamplifier lists for $3900. Adding the sophisticated DM35 DAC module increases the price to $4400. Include the SM35 Prisma network module, the price becomes $5000, and you have the Primare PRE35 Prisma.

Jacks and knobs and circuit boards
Without turning this review into a user manual, here's a brief summary of the available inputs and outputs: five analog inputs (two pair balanced), nine digital inputs (four TosLink, two S/PDIF on RCA, one USB-A, one USB-B, one LAN/Ethernet), Wi-Fi and Bluetooth antennae, two balanced and two unbalanced outputs (including one line pass-through on RCA), one digital output (S/PDIF on RCA), and a LAN output. Also onboard are the usual trigger connections and an RS-232 for integration. Oddly, given the surfeit of connection options, there is no AES3 digital input, which I like to have for my CD transport, and no headphone jack. On the analog side, balanced signals run fully balanced—and fully analog—from input to output.

The PRE35 Prisma is a classic one-shelf unit, standing 4.2"tall on three high-quality, twist-to-level feet. The PRE35 Prisma runs cool and can be stacked with other components. The front panel is spare, with two large multifunction knobs and four diminutive buttons; front-panel functions are duplicated on the included remote. A relatively small display provides basic status information. If my intuition has been right all these years and the feel of the knobs on an audio component is a clue to its quality, then the PRE35 is of the highest quality: Its hefty metal chassis is complemented by sturdy, solid knobs. Primare may be manufactured in China, but it is designed in Sweden.

To get a fuller picture of the PRE35 Prisma than I could from the manual and website, I turned to Terry Medalen, Primare's marketing manager. He told me that the linear power supply of the PRE35 Prisma uses a custom-wound R-core transformer and is in a switch mode for standby only; it switches to the linear supply. Primare puts much focus on their power supplies: "Thoroughly implemented power supply designs" is the first item listed in the "Design Brief" for the PRE35 Prisma.

This is a preamplifier, so the volume control matters. The one here, Medalen explained, is a "2 × 4 channel balanced mode IC selected for optimal channel balance and low listening level performance—the IC is completely out of the signal path." It works in increments of 1dB between 21 and 54 (on the front-panel read-out) and in 0.5dB steps from 55 through 99. Finer control at louder levels makes perfect sense.

The volume control, internal DACs, and network electronics can create noise issues; the PRE35 Prisma addresses this with short circuit paths, careful circuit implementation, and the use of four-layer circuit boards (one layer serving as ground), and surface-mount components, which act as antennas less than larger, conventional components do.

The PRE35 DAC is based on a flagship AKM DAC chip, the AK4497EQ. This chip is said to be "capable of achieving 128dB (stereo) S/N and –116dB THD+N, while supporting up to 768kHz PCM and 22.4MHz DSD. This ability to handle higher resolution file formats will allow for the potential of future software upgrades," according to the design brief. The AK4497EQ also includes "a newly developed switched capacitor filter 'OSR Doubler' that greatly reduces sound degradation from noise shaping, achieving a flat noise floor up to 200kHz."

Forming connections
Both consumers and designers of high-quality audio equipment face a new set of challenges due to the fact that, for better and worse, hardware and software have become bedmates demanding reciprocal consideration. Audio companies must now employ or collaborate with software designers, and we must learn to work with the products of these collaborations, including app integration and an ever-developing feature set. During my review of the PRE35 Prisma, a number of these hardware/software marriages were still in progress and had not yet been consummated. Terry Medalen updated me about some of Primare's engagements, current and future. Software is updatable online via the network connection. •

• The PRE35 Prisma is designed to be controlled by the multiroom Primare Prisma app, which is available for iOS and Android. Currently, the app facilitates component setup, integrates internet radio, allows access to music files stored on your local network, and provides links allowing you to access local streaming services via Chromecast, AirPlay, Bluetooth, and Spotify Connect connections—but see below.

• In the coming months, Qobuz and Tidal will be integrated into the Prisma app, allowing gapless playback with both services. Once that happens, Qobuz will provide gapless playback up to 24/192 and Tidal will support gapless playback and MQA decoding to the first full unfold at 48, 88.2 or 96kHz.

• At the time of testing, Roon relied on AirPlay or Chromecast to connect to the PRE35, limiting resolution to 16/44.1 (AirPlay) or 24/96 (Chromecast). But a firmware update scheduled for March—around the time you're reading this—will implement RaaT, Roon's industrial-strength streaming protocol, which aims to support "all relevant audio formats, now and in the future," both wired and wirelessly. At that point, the PRE35 will be certified "Roon Ready."

• Once Tidal is fully integrated with the Prisma app (and also with Roon), Tidal Connect and the forthcoming Qobuz Connect will be superfluous, so they won't be supported.

• Primare's approach to Bluetooth is unusual. Recognizing the limitations of all current Bluetooth implementations, they utilize an older version (Bluetooth 4.1 and its basic SBC codec) in a configuration optimized for casual listening. Want better sound? Choose a better connection.

• In an interesting bit of future-proofing, the PRE35 supports WiSA for connection to wireless speakers. WiSA facilitates connections at up to 24/96 with near-zero latency and speaker synchronization up to a microsecond. According to research, that's well below the threshold for human discrimination.

Initially, I relied on my laptop's connection to Wi-Fi and used a USB cable to connect to the PRE35 Prisma. Later, I connected the router directly to the Primare with an Ethernet cable. I also tried the Wi-Fi connection, and it worked fine, but I used the Ethernet connection for all my serious listening.

For setup, I sat close, with my reading glasses on, because the display on the PRE35 Prisma, as I mentioned, is quite small. Settings are configurable in five categories—general, input, audio, streaming, and network—and include customizing standby behavior, volume at startup, maximum volume, and input gain. Even Mute is adjustable: from 0 up to any setting you choose.

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Footnote 1: See Herb Reichert's April 2020 review of Primare's A35.2 power amplifier here and Kalman Rubinson's November 2022 review of the A35.8 power amplifier here.