Aurorasound HFSA-01 Integrated Tube Amplifier

Shinobu Karaki-san's brand new hybrid is out - the HFSA-01 Integrated Amplifier, utilizing EL84 valves with an output of 14 Watts per channel.

HFSA-01 is a hybrid integrated amplifier utilizing the advantages of both vacuum tube and semiconductor. The tube EL84 delivers 14W + 14W power output. The model is equipped with bass and treble controls. The input stage has a built-in phono equalizer for MM-type cartridges, along with 3-channels of RCA unbalanced input terminals. This model accepts speakers with 4Ω to 8Ω impedance. In addition, it has a headphone output. HFSA-01 is designed with unconventional  configuration, however, it fulfills the basic requirements such as sound quality and overall performance for a wide range source from high-resolution digital to analogue records that any generation and age demands. The front panel is ornamented with Mahogany wood on both sides to enhance the retro appearance producing a rather relaxing atmosphere for more enjoyable audio life.

The HFSA-01 now comes with Aurorasound's "Easy Compensator". That's a front plate overlay for the Bass/Treble controllers to adjust the phono input to various EQ curves (RIAA, DECCA, Columbia, AES, NEB). This hidden feature is a very useful tool for vinyl aficionados.

Also new: for a surcharge of $199 the standard plastic knobs can be replaced with real mahogany wood knobs.

In stock - shipping now.

Features
The output vacuum tube EL84, a pentode equivalent to 6BQ5, is operated in push-pull configuration delivering extremely low distortion and excellent frequency characteristics with ultralinear connections. The driver for EL84 is a wellknown Texas Instruments OPA604A, a high precision audio Op-Amp. Aurorasound developed a perfect phase inverter circuit with OPA604A to drive the push-pull operation in the most ideal way. The tone-control section employs a CR-type for easy adjustments to achieve more rich bass and comfortable treble to meet listeners’ taste even with small-size speakers. The phono equalizer uses Linear Technology’s semiconductor to achieve an excellent S/N characteristic with NF-type circuit configuration. The power supply section is completely isolated between the vacuum tube and semiconductor to completely eliminating any interferences regardless of volume level and frequency range. The rectifier is of the super low noise Rohm’s silicon carbide diode. The output transformer and power supply transformer are custom designed by Aurorasound, and manufactured by a Japanese company. This model employs carefully selected high-quality capacitors and resisters, as well.

 - 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
 - Upgrade to SR MASTER fuse available (+$250)
 - Power consumption: 150W
 - Size / Weight: W360 x D320 x H145mm / 10.3kg (14 x 12.5 x 5.7inch / 22.7lbs)

Michael Lavorgna of Twittering Machines concluded (September 2023):
"... 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..." CLICK HERE to read the entire review

Janine Elliot of the HiFi Pig Magazine writes (September 2023): 
"...this was a highly engrossing product giving me tons of fun per watt. Everything was harmonious with excellent clarity and a fair amount of dynamism for such a small output. Mids were sublime and top end was pin sharp and fast. The unimposing exterior hid within it a product of excellent calibre, and well worth exploring if you perhaps don’t want to annoy the whole street..." CLICK HERE to read the entire review

David Abramson of The StereoTimes wrote (August 2023):
"...he has created an op-amp/tube combo circuit that really does combine the best of solid-state low-end punch and drive with the (not at all overdone) punchy/spacey liquidity of EL84 tubes in the mids and highs, resulting in a lively, spacious, punchy sound which occurs within expansive spaces that suggest much pricier ‘purist’ tube or solid-state amps..."

"...String textures here were readily apparent, and the HFSA-01 resolved detail better than most any amp I’ve had through here, clarifying and illuminating and generally bringing this beautiful collection of heretofore unfamiliar (to me) symphonic pieces to life in my listening/living room..." 

"...'Exactly Like You' from Best of the Ray Brown Trio showcased two of the special attributes of the Aurorasound; namely, it is especially dynamic (macro and micro) and especially well defined in the mid-bass. On 'Freddie Freeloader', Ray Brown plays a descending scale on the standup bass, and you can hear the string texture and woody resonances as separately defined notes descending down into the lowest reaches of the scale just as clearly as you can on the higher end..."

"...my hat is off, and my head is bowed to Shinobu Karaki-san. This one is special. If amplifiers were akin to people, the Aurorasound HFSA-01 might be Garland or Sinatra, born and bred to perform. In answer to your next question, yes, of course, I bought the review sample. I can’t let this one go..."
CLICK HERE to read the entire review 

Wojciech Pacula of HighFidelity.pl wrote (July 2023):
"... FOR A LONG TIME, THERE WAS NO small, tube amplifier on the market that would work as well with loudspeakers as with headphones. The Aurorasound HFSA-01 fills this gap perfectly, as if it's always been there. It plays with an open, clear sound of extraordinary energy. Its sound is not muddied or lifeless, as it happens with large devices. At the same time, it has enough authority at the bottom of the band to show the scale of events, the volume of instruments and the depth of the soundstage... A beautiful example of minimalism in the spirit of zen combined with modern solutions. From us, a saturated, full of red color award the RED FINGERPRINT..."
CLICK HERE to check it out.