Audiophilepure

A key feature of the preamp is its two chrome-plated, ball-bearing rotary controls, which feel solid, heavy, and precise during use. The step size of the volume change depends on the rotation speed. Slow rotation changes the level in 0.5 dB steps, while fast rotation changes the volume in 2 dB steps. Unusually for a high-end product, the preamp includes Bass, Treble, and Loudness controls that can also be fully bypassed. Even though there are valid arguments against using EQ, there are times when it can be beneficial. Thus, I always welcome the inclusion of this almost forgotten feature.

The preamp, presumably mandated by law, has an Auto-Standby feature that switches to standby after 15 minutes of inactivity, which can be quite annoying for a tube product with a warm-up period. Fortunately, the function can be defeated in the Personal Setup menu. The manual indicates that “the menu button on the right under the display” must be pressed before waking the unit from standby. To be fair, it says “on the right”, but confusingly, the middle button has a ‘Menu’ label, while the other buttons are unlabeled. As it turns out, the unlabeled button on the far right opens the Personal Setup menu, not the Menu button. With that addressed, I left the preamp powered on for most of the day before starting my listening tests.

Even within their given size constraints, it is quite an achievement to embody as much of the music’s energy as they can and to follow what is given, overlaying and forming an above-expected level of acoustical nodes and focal points, creating an enticing atmosphere.This is undoubtedly due to what Bloom stands for and how everything is combined, starting with the selection of drivers, fitting enclosure, and a potent, fluidly tuned crossover.

The Blooms are an exemplary execution of the bonding of three key elements, and as proven during the evaluation, they were designed to be an important partner to the matching electronics

https://www.enjoythemusic.com/superioraudio/equipment/0626/AGD_Productions_Allegro_Intergrated_Amplifier_Streamer_DAC_MM_MC_Phonostage_Review.htm

The second selection was “Space Oddity,” by David Bowie, from Space Oddity (2019 Mix). This turned out to be perhaps the most interesting selection of the entire review. The track played flawlessly. The amount of information that could be heard was so substantial that it seemed like hearing the selection for the first time, and truthfully, I know I have said that before. The part I have not said before is that there were underlying elements in the music that were not as notable before. For example, there were guitar notes that seemed almost out of place. Normally, they would’ve been either so muddy they would have blended in with the rest of the music, but although the rest of the music played, these were visible now. In the end, it turned out to be just this version, but it highlighted the detail and resolution, not to mention the sound quality the Allegro can produce in the right system.

The third selection used for the review was “Queen Mary” by Francine Thirteen. It is a great track to test just how well an amplifier can handle a genre or musical selection that demands large power fluctuations. The first thing that struck me about the AGD Allegro was just how controlled the soundstage was with this selection. The music was tight, the notes extremely fast, and the vocals were exceptionally lifelike. Regardless of the challenges the material placed on the amplifier, the Allegro was up to the task, even under significant changes and heavy demands.

https://www.hifinews.com/content/simaudio-moon-371-integrated-amplifier

Just as Melua’s vocals sounded floaty and smooth through the MOON 371, the cigarettes-’n’-whiskey growls of Johnny Van Zant across Lynyrd Skynyrd’s acoustic Endangered Species [Volcano 82876 55128 2] were roughly detailed, as appropriate. However, listening to ‘Devil In The Bottle’ it did feel as if the singer was spread a little too wide, not quite drawn sharply centre stage amid the instrumentation. This vaguely diffuse flavour was also noted with Ry Cooder’s ‘Theme From Southern Comfort’ [Ry Cooder Anthology: The UFO Has Landed; Warner/Rhino 8122-79891-9]. Yes, the snap and twang of his slide guitar was all there, but perhaps it was not so ruthlessly defined.

The Mathilde Storm ballad ‘Cries Like A Baby’ [Propeller Recordings download] has a sparkling vocal track that runs the risk of listener fatigue. The MOON 371 delivered it with no shortage of presence and detail, while avoiding the gritty treble that has one reaching for the volume control. The fulsome bass on this recording, both soft yet robust-feeling, was another standout element.

Female vocals and instruments like the piano especially sound detailed and expressive. There is a clean attack and natural decay to the notes.

Guitars and strings are full of that enjoyable top-end bite and nuance. Cymbals have clean, crisp edges, with plenty of natural shimmer to offer. You get a natural metallic tone that feels well separated. Gentle sparkle and clean, refined shimmer. No thinning of notes, no hot regions, no sharpness or piercing edges.

Towards the extreme top end, Diamond feels quite spacious and extended, giving instruments the breathing room they ask for.

Thankfully, the upper treble region is smooth here. That is the region I am usually extremely worried about. Even a slight extra focus there can feel off to me. But not here.

Overall, that balance of detail, air, and sparkle is achieved very well on the Diamond, without sacrificing any energy or extension. This is one of the best treble presentations a single dynamic driver can truly achieve.

https://www.enjoythemusic.com/superioraudio/equipment/0626/Nagra_PREAMP_II_S_Review.htm

One might assume that because this Nagra preamp was powered by tubes, it should have sounded tube-like. Not so. Even when I squinted my ears to hear these characteristics from the Preamp II-S, I could not detect even a hint of “tube sound.” Its presentation sounded neither like a tube nor a solid-state preamp. The Preamp II-S sounded like an outstanding preamp. Period.

I suppose there was one trait of the Preamp II-S that made it sound a bit more tube-like, but this was a positive: it was the II-S’s ability to maintain a dynamic distance between sounds. When two instruments or voices were located in the same place in the soundstage, not only could this preamp separate the two sounds, but it also made their volume differences much more audible. Its dynamic distance gave rise to an almost indescribable ability to hear “behind” each sound. I’ve also heard this trait in some very high-quality solid-state components, but it’s more common in tube-powered equipment.

Near the end of the review period, I swapped out the Nagra Preamp II-S for the other in-house linestages, those that I listed earlier in the review. These linestages were all very high-quality components, but when I returned to the Preamp II-S, it seemed to have all the qualities of these other components, but enhanced their traits significantly. These refinements were true regardless of which trait I was considering.