There are times when I forget I’m reviewing, something that happened more than the norm during my time with the lovely Aurorasound HFSA-01.
Part of the problem is, the only real job any of us have as listeners is to listen. Ideally enjoyment ensues. And when things work out this simply, as was the case with the Aurorasound integrated amp, I find it difficult to leave listener enjoying music mode to get back into reviewer mode. Perhaps ‘difficult’ is a poor choice of words because nothing about living with the HFSA-01 was remotely hard.
The Aurorasound HFSA-01 (High Fidelity Stereo Amplifier no. 01) Vacuum Tube Integrated Amplifier is a hybrid design, but not in the way most people think when it comes to tubes and integrated amplifiers because the HFSA-01 pairs a solid state preamp with a tube amp, using a phase inverter in between. Kinda the reverse of the norm. A Texas Instruments OPA 604 A op-amp is used in the driver stage to bring the quad of Sovtek EL84s to life, two per side, while a Rohm silicon carbide diode is employed for rectification. The EL84s are run in ultra-linear push-pull mode, putting out a specified 14 Watts per channel. [footnote 1]
In addition to the 3 line level RCA inputs, the HFSA-01 also includes a Moving Magnet Phono input. 4 and 8 Ohm speaker outputs allow you to match the HFSA-01 to your speaker’s preferred load. An IEC inlet awaits your power cord of choice if you decide to skip the included cord.
As you can see, the HFSA-01 packs a pair of beefy iron core output transformers and a power supply transformer inside, which are custom designed by Aurorasound and manufactured by an unnamed Japanese company. There are a number of quality parts in use including an Alps volume pot, Dale resistors, WIMA and Nichicon caps, and DALE resistors.
Up front reside defeatable tone controls using the toggle switch below, volume control, input selector, and another toggle switch for Stereo or Mono mode. But wait, there’s more:
Those Tone controls do double duty as EQ Curves for the Phono input to properly play back pre-RIAA records! To my mind, this is a wonderful, and I mean wonderful, and uncommon feature to be found in a $3800 integrated amp. Nice! and it makes that Mono toggle switch make even more sense.
The headphone output is powered by the preamp’s op-amp, not the EL84s as you can see in Aurorasound’s block diagram of the circuit.
To my eyes, the HFSA-01 checks all of my visual and build quality boxes with its retro appeal. If you’ve read my review of the HiFi Bargain overachieving VIDA Prima Phono Stage (review), you already know that Aurorasound also packs in loads of performance. Lovely, music-making performance.
I paired the HFSA-01 with the recently review Living Voice A25R but it spent the lion’s share of Barn time driving the Barn resident DeVore Fidelity O/96 (review). The Auralic ARIES G1.1 streamer (review) fed the totaldac d1-unity (review), while the Michell Gyro SE turntable, Michell T8 tonearm, and Ortofon 2M Black MM cartridge handled my records (see full system and Barn details).
Subaerial by Lucy Railton and Kit Downes was recorded in the Skáholt Cathedral in Iceland, where Downes made use of its organ accompanied by Railton on cello for 41 minutes of improvised magic. The place and space of this recording act as accompanists as well, and the mighty Aurorasound amp did an amazing job recreating the instruments, space, and interplay, bringing this music out into the Barn with gripping clarity and full voice. This recording also showed off the HFSA-01’s bass response prowess, its force, control, and rich timbre leaving little, if anything, to be desired. It is that good.
Anna & Elizabeth’s The Invisible Comes to Us from 2018 is a recent find, and I’m very happy I found it (with Roon Radio’s help). Folk inspired with unexpected structures, Anna Roberts-Gevalt and Elizabeth LaPrelle weave intricate songs from synthesizers, bird song, found sounds, drones, loops, guitars, vocals, and hard-edged noise. Very much like Subaerial, The Invisible is in love with sounds, presented here with unexpected variety, like finding a knight on horseback trotting down Flatbush Ave. Spoken word, electronics, layered cut ’n paste style, William Burroughs meets Sibylle Baier, and all of this wonderful sound and music came spilling out into the Barn as ripe and ready for digestion as I need to get lost in its intricate workings. Crisp when called for while sounding perfectly paced and in time with the sound collage of delights, the Aurorasound/DeVore duo gave this richly varied voiced record the full spectrum treatment, sounding as rich and ripe as Anna & Elizabeth’s vivid imaginations demand.
From a comparative point of view, the HFSA-01 is not as full-bodied and powerful sounding as the Barn resident Leben CS600 integrated amp, albeit at more than double the price of the Aurorasound and without a phono input. But I will say I was surprised by the HFSA-01’s bass prowess that never left me pining for my beloved Leben. Don’t get me wrong, the CS600 offers even greater riches in sound and control, but taken on its own, the Aurorasound could easily be my main squeeze when paired with the O/96. It is that good, offering clarity, control, and a wonderfully rich sound. If you want over-ripe romance, keep looking because the HFSA-01 is in no way soft or overly lush, nor does it have that grainy sound that can come with lower priced amps, tube or solid state.
It don’t mean a thing if ain’t got that grind. Dogsbody from Model/Actriz is a dizzying badass ride through the darker noisier parts of town and the Aurorasound/DeVore duo proved perfectly dynamic and capable of delivering every last ounce of manic energy from Brooklyn-based vocalist Cole Haden, guitarist Jack Wetmore, drummer Ruben Radlauer, and bassist Aaron Shapiro. Once again, Shapiro’s bass was fully voiced, dimensional, and powerful while the rest of the band’s grunt, drive, and grunge came through the O/96 and into the Barn with real danger. Loud and louder, as loud as I care to listen, Cole Haden leaning in close mic, “I’m pressed against the glass, as close as I can take” with the metallic sheen glinting off Wetmore’s guitar with live-like bite, the HFSA-01/DeVore pairing had a firm grip on all the menace Model/Actriz could muster.
While the Leben offers more meat, more apparent body and weight giving this music greater physical impact, the Aurorasound’s slightly leaner sound never felt thin or overwrought. The thing about comparisons and comparative listening is they are temporary, transient tests, making difference the focus when, in fact, music is always the more meaningful focus. And I’ll remind readers that the Barn is a big place with lots of space to fill (18’ x 35’ x 12’ on the A-Side) so for listeners with rooms, not Barns, to fill and equally friendly speakers to drive, the HFSA-01 should pack as much punch as you need.
How about that MM phono input? This is one aspect of the HFSA-01’s performance that didn’t come as a complete surprise because I still remember some of the VIDA Prima’s standout qualities, many of which are shared by the HFSA-01.
Lucrecia Dalt’s ¡Ay! from last year remains a favorite record for its garden of earthly delights delight in sounds, atmospheres, and bodacious beats. OK, I was surprised by how well the HFSA-01 reproduced this enchanting record in Barn, filling me and the space around me with richly colored resolute goodness. Big fat fully voiced bass, all of the insect-like quirks and chirps coming from everywhere but the speakers, and Dalt’s slow vocal dance over the top felt as wet, ripe, and rich as a rain forest.
I ran through a bunch of albums over the course of the 2+ months of time the HFSA-01 lived in Barn and it impressed by offering the same finely resolved, rich, fit, and full sound as illustrated by ¡Ay!. This phono input is no afterthought, it is, all things considered, a live with and love kinda deal. Of course you can spend more on an outboard phono stage, but why would you when buying the HFSA-01? To my mind, the price/performance of the HFSA-01’s package is a thing of beauty that you shouldn’t mess with.
I am getting to know the newly Barn resident and lovely Focal Clear Mg headphones and what better way to bounce around in their sound than with Aleighcia Scott’s breezy Windrush Baby.
Welsh-Jamaican singer Scott knows her way around a groove, and this is pure Reggae pumping from seasoned Jamaican musicians with producer RoryStoneLove at the helm. With this kind of sound, this kind of performance, I could easily ease into some real private listening time, as the Focal/Aurorasound offered a crisp, rich, and fully realized bass from Windrush Baby like honey for the ears. Nice. So nice.
I also couldn’t resist taking those tone controls for a spin with this music, dialing up the bass to dance hall levels. To my mind, tone controls are a nice to have feature, especially when you can take them out of the circuit with the flip of a toggle switch.
I choose my hifi gear based on everything—looks, build quality, company, performance, features, and price. When it comes to an integrated amplifier, especially in the HFSA-01’s price range, I like having a MM phono stage built in and even a headphone amp for good measure and I put the HFSA-01’s EQ Curves in the crazy-amazingly nice to have category. Add in its retro good looks, rich fit and feel, price, and performance that left me wholly satisfied, opening as big a door onto musical enjoyment as I need, I cannot sing the Aurorasound HFSA-01’s praises loudly enough to anyone looking for an integrated amp that will feed your love of music with endless delight.
1. Aurorasound has made a change to the HFSA-01 cabinet, offering easier access to the EL84s through a removable panel.
Aurorasound HFSA-01 Vacuum Tube Integrated Amplifier
Price: $3,680
Company Website: Aurorasound
US Distributor Website: highend-electronics
Specifications
Input: RCA unbalanced – CD, LINE-1, LINE-2, Phono-MM (Gain 40dB, load resistance 47kΩ, RIAA +/-1dB)
TONE Control: BASS +/-12dB, TREBLE +/-12dB
Output: 14W + 14W into 8Ω speaker
Frequency response: 10Hz ~ 40kHz, -3dB, Flat
THD+N: 0.08％, 1kHz, 2W, A-weighted
SNR: 93dB, LINE IN-OUT
Functions: TONE control pass DIRECT SW, Stereo/Mono, Headphones output
AC voltage: USA model 120V, Europe/Asia model 220V, 240V
Power consumption: 150W
Size / Weight: W360 x D320 x H145mm / 10.3kg (14 x 12.5 x 5.7inch / 22.7lbs)