In his review of the Simaudio Moon 791 streaming preamplifier, published on this site on December 1, 2023, Doug Schneider describes the 791 as a feature-rich successor to the company’s 740P preamplifier, released more than ten years ago. “The 740P was strictly a line-stage preamplifier [that] provided input switching for balanced and single-ended analog sources, gain for all incoming signals, and volume control,” Doug writes in his review. The 791 still provides these functions, but it also incorporates a phono stage that’s compatible with moving-magnet (MM) and moving-coil (MC) cartridges, a digital-to-analog converter (DAC) that supports nearly all of today’s music file formats, and Roon Ready streaming, wired or wireless (Wi-Fi or Bluetooth), via Simaudio’s MiND 2 platform. These additional capabilities partly account for the 791’s much higher price: $16,000, compared to $9500 for the 740P (both USD).

The 791 is similar to the 740P in appearance and size, Doug observes, but it has been updated cosmetically and functionally. The changes include “sloped tops on the cheeks and middle section of the front panel” and new metal footers that “embed a polyurethane-based suspension system and terminate with small plastic bumpers.” The new 4.3″ front-panel color display not only looks much better than the 740P’s red-dot LED display but also provides much more information and functionality. Included with the 791 is the newly developed BRM-1 remote control, which Doug describes as being “light years ahead of the pushbutton-festooned wand-type remote that came with the 740P.”

Technically, the 791’s default gain setting is 9dB, 3dB higher than the 740P’s, and its finest volume-control granularity (for both the front-panel and remote controls) is coarser than the 740P’s: 0.5dB steps, not 0.1dB. Simaudio determined that the 740P’s 0.1dB steps were too subtle for most listeners, Doug explains. The 791 also has many more rear-panel connections than the 740P did, he writes, having “a whole slew of digital inputs that the 740P didn’t have.”

Surprisingly, the additional features and input options seemed to have no adverse effect on the 791’s sonic performance. Doug has always been impressed by the 740P’s inherent quietness—it contributed no sound (noise) of its own—so one of the first things he did with the 791 was to “turn the volume wide open and put an ear to a tweeter”—and listen. He found that whether paired with the Moon 761 power amp or the NAD M23 power amp, the 791 generated practically no noise. When he repeated the test with the 791 set to the phono input, configured for a moving-magnet cartridge (40dB of gain), he did notice some noise, with both amps, but “that’s what you’d expect with such massive gain—40dB is a hundredfold boost to the audio signal!” he points out, stressing that “for a phono stage, it was very, very quiet.” The 791’s absence of noise, as well as its extraordinarily low levels of distortion, was later confirmed by test-bench measurements performed by Diego Estan, SoundStage!’s electronics-measurements specialist.

Doug began his critical listening with vinyl, using his “modest rig”: a Pro-Ject X1 turntable equipped with a Pro-Ject Pick it S2 moving-magnet cartridge. Using LPs he knows well, he quickly determined that the 791 sounded “exceedingly neutral,” but he felt that the 791’s quiet phono stage and nearly silent line-stage section could “potentially reveal much more sonic detail than the Pro-Ject X1 could provide.” (The 791’s phono section later proved excellent in the measurements too, in precise adherence to the RIAA equalization curve and in low noise and distortion.) The thought that the 791’s phono section was outclassing Doug’s turntable gave him the impetus to begin investigating higher-quality turntables in search for one that is a better match for his system.

“Digital playback was another story,” Doug writes, having discerned “no sonic limitations” whether streaming or playing locally stored music files. “The sound was neutral throughout the audible range,” he reports, describing it as “spectacularly clean [with] the clarity for every sonic detail to flow unimpeded to the speakers.” Playing “Pacing the Cage,” from Bruce Cockburn’s The Charity of Night, Doug remarks on how pure the sound was and writes, “I hesitate to use the word smooth to describe what I was hearing because to some audiophiles that implies a high-frequency rolloff or a glossing over of details—there was none of that. Smooth, though, aptly describes the dazzling sense of clarity and cleanliness the 791 imparted to this music.” To test the 791’s ability to convey low-level details, Doug then played an original CD of Blue Rodeo’s 1989 Diamond Mine album. “With practically no obscuring noise from the electronics,” he recounts, “I could hear everything clearly even at low volume levels.”

The 791 produced an exceptionally clean, low distortion audio signal, but it also “asserted no sound, coloration, or character of its own,” Doug writes. “It simply got out of the way and passed the music signal through.” Of course, a reference-class preamplifier is supposed to quietly get out of the way, he notes; it’s just that the 791 manages to do it “with a considerable number of bells and whistles attached.” (In a supplemental article published concurrently with the 791 review, Doug highlights the 791’s “unmatched combination of features and performance.”)

Simaudio’s Moon 791 has received much attention and much praise on SoundStage! Network sites during 2023, as did the Moon 740P ten years earlier. In the December 1 review, the 791 earned a Reviewers’ Choice award, as the 740P did in 2013. The next accolade came on December 15, when the 791 was recognized as one of the Products of the Year for 2023, as was the 740P before it. Now, the Recommended Reference Component award is yet another formal recognition the 791 shares with its predecessor. And while garnering the same accolades, the 791 far surpasses its predecessor with its DAC, streaming module, phono stage, and broad connectivity. That it does so without compromising performance is a stunning achievement fully deserving of every honor that the SoundStage! Network can bestow.

Manufacturer contact information:

Simaudio Ltd.
1345 Rue Newton
Boucherville, QC J4B 5H2
Canada
Phone: (450) 449-2212

Email: info@simaudio.com
Website: www.simaudio.com