PS Audio Sprout100 Integrated Amplifier

Small Package, Big Fun

Equipment report
Integrated amplifiers
PS Audio Sprout100
PS Audio Sprout100 Integrated Amplifier

Very early on in my TAS tenure, in Issue 259, I had the pleasure of reviewing the original Sprout integrated amp, and it delighted me so much I bought the review sample. So when I found out there was an updated and upgraded Sprout100, naturally I was intrigued. After reading and editing so many reviews from TAS writers, then later having the opportunity to peruse their reviews of the next-generation versions of the same products, I now get my turn to take that route. It feels like a milestone, and happily it’s been rewarding to discover that the new li’l Sprout100 delivers an outsized array of big improvements both inside and out. Not only does this 100Wpc successor pack double the prior model’s power, it also exceeds it in sonic prowess and flexible functionality—whether you dig digital, analog, or both—while adding a few other new small yet significant details. Both Sprouts were conceived by Scott McGowan, PS Audio founder Paul McGowan’s son, who also serves as sales director for the Boulder, Colorado, company. Clearly the McGowans and their team paid attention to customer feedback for the next-gen Sprout100’s product development.

In form the Sprout100’s clean, retro-inspired aesthetic remains the same—as do its weight and diminutive dimensions. I’ll admit, as I have before in these pages, that I’m a sucker for sexy design—in addition to great sound, of course—so this compact amp appealed to my eyes and hands before my ears. Adorned with a real-walnut top and trimmed in solid aluminum, it strikes an elegant balance between cool and cute, between natural wood and streamlined machine. The front panel features two machined-aluminum rotary knobs—one for stepped volume control, power on/off, and bass boost on/off, the other for input selection (vinyl, analog, digital, Bluetooth). There is also a ¼" headphone jack (an adaptor for 3.5mm is included) on front. The volume knob turns smoothly but lacks a line to show its degree of rotation. Being unsure of its level, I hesitated at times to crank it up, as it kept turning and turning. This odd, if minor point aside, the Sprout100’s operation couldn’t be more convenient or user-friendly, amounting to a quick push of a button or turn of a knob. No impenetrable deep-dive menus or complicated touchscreens here. The Sprout100 now comes with a remote control for basic functions; the original was strictly hands-on in operation.

On the old model, the power switch was a toggle on the back panel, i.e., out of sight, so I would have to put my hand on top to check the unit’s temperature to determine whether it was on or off. (Also neither model has a dedicated AC mains switch.) A small (literally) but useful improvement in the new Sprout100 is a teeny-tiny LED status indicator displaying whether the power and/or bass boost is on or off, etc.

As befits PS Audio’s high-end audio ethos, this sleek and stylish little package also contains about as full-featured an integrated amp as you could wish for. There’s a newly redesigned phonostage (moving-magnet only, fixed gain and loading), a swanky new DAC (an ESS Sabre 9016 that decodes 128DSD and 384/24 PCM), and Bluetooth 2.0. Other new features in the Sprout100 include an optical input, a variable mono subwoofer output, and “bleeding-edge” ICEpower amplifier technology. Indeed, as I’ll soon describe, the Sprout100 delivers a much bigger, bolder sound than its name and size would suggest. It’s quite portable as well, and international travelers/markets may appreciate the universal AC voltage input, which handles anything from 100–240VAC 50/60Hz. The Sprout100 also ships with a 6-foot power cable, four gold banana speaker connectors, a headphone jack adapter, and an owner’s reference manual with clearly detailed and helpful instructions geared toward newbies and more seasoned audiophiles alike.

Conveniently, my review of this small-footprint integrated coincided with my recent move into a new space, so I was able to enjoy music more immediately through a fine yet simple system that was quicker and easier to set up than my current reference gear. The Sprout100 served as a capable core in front of single-driver Air Tight Bonsai loudspeakers connected via AudioQuest Venom cables with my iPhone 8 Plus via Bluetooth as a “quick-and-dirty” source, playing back mostly Tidal tracks, or my MacBook Air using Roon. In my previous abode, I’d set up the original Sprout in the same configuration, and during my critical listening I swapped the old unit in for more direct comparison with the updated model. Right from the get-go, dramatic differences between the old and the new jumped out at me: heartier low-end (particularly with bass boost on), wider dispersion with more openness and sense of depth, lower noise floor, and higher resolution.

Firing it up on some funky tunes, I was immediately struck by the Sprout100’s bigger, better bass. Exhibit A: The heavy, deeply funky grooves and bass lines of Nina Simone’s “Funkier Than a Mosquito’s Tweeter” from the remastered Miss Simone: The Hits were reproduced with satisfying substance. Leopoldo Fleming’s congas conveyed convincingly quick, crisp snap on attacks; other percussion layers from tambourine to kickdrum were also cleanly rendered with body and texture. Obviously with one-way speakers, one can’t expect outsized images and cavernous soundstaging but the Bonsai’s powerful single-driver coherence and openness carried the day.

Speaking of bass, the Sprout’s bass boost option comes as the default setting, and, depending on the source material, it often became my default. Although the term “bass boost” might suggest more “bottom-up” sonics, its effect was more subtle, not obvious or overblown; it seemed to provide a slightly more substantial foundation, like the stiffer underpinnings of a garment, keeping the low end, uh, tighter. Generally it enhanced the kinds of music you’d expect it to: dance, electronica, rock, etc.—music that tends to be heavier on bass. It did fewer or less apparent favors with detailed acoustic music, and more intimate and closely miked recordings, such as jazz combos, but neither did it detract from them.