This week, we tested the Audio Technica AT-HA5050H headphone amplifier with DAC. An exceptional amplifier, fitted with a digital to analog converter compatible with 32 bits / 384 kHz and DSD audio stream up to 5.6 MHz.
Audio Technica AT-HA5050H- introduction
The Audio Technica AT-HA5050H was developed to power demanding earphones, headband headphones and hi-fi headphones. The H in AT-HA5050H stands for ?hybrid’, as the amplifier uses two ECC88 tubes for its preamplification section, while the amplification is handled by transistors. This technique is used to combine the ?warmth? of tube sound with the power of transistors (for low sensitivity headphones such as orthodynamics for example). Audio Technica selected the electronic components of this amplifier amongst the best manufactured by Nichicon, Wima, Lundahl, Toshiba or JJ Electronics for the power tubes. All the components used in the circuit to convey the signal are sorted and paired. Four types of inputs are available- two stereo analog inputs (RCA and XLR) and three digital inputs (coaxial RCA and optical Toslink S/PDIF, as well as type B USB).
Audio Technica does not mention the type of DAC used, but based on the technical characteristics and the sound signature, it is possible that the chip used is a Burr Brown model (probably a DSD1793, to be confirmed).
Audio Technica AT-HA5050H- functions
Capable of powering two sets of headphones simultaneously, this amplifier features four 6.35 mm jack outputs for a total of eight outputs. Each has different output impedance characteristics- 0.1 Ohms, 33 Ohms, 82 Ohms and 120 Ohms. Each output offers a different level of gain and sound signature. For example, the 0.1 Ohms output delivers an important sound volume and a high level of precision, while the 120 Ohms output offers a softer sound with an omnipresent bass range. At the back of the device is a level attenuator (0 or -12 dB), a very convenient feature with a BitPerfect digital source (when the USB source doesn’t offer the possibility of adjusting the level for example) and when a high sensitivity set of headphones is used with the 0.1 Ohm output. It is possible to benefit from a wider volume adjustment range when the attenuation is activated. The USB port features two working modes- adaptive or asynchronous. We carried out our listening sessions in asynchronous mode as this type of connection offers a better quality.
Aside from the input selector and volume potentiometer, the front panel features an audio stream resolution indicator ranging from 32 to 384 kHz in addition to DSD64 and DSD128 (2.8 and 5.6 MHz). Lastly, the front panel is fitted with two backlit VU meters which indicate the dynamic range of the currently played audio track. A 4 position attenuator allows the user to adjust the scale (so that the needle isn’t constantly in the red when the volume needs to be turned up for low sensitivity headphones).
Audio Technica AT-HA5050H- test configuration
We connected the Audio Technica AT-HA5050H headphone amplifier to the USB port of a Raspberry Pi2 working with Volumio OS. Although very affordable, this computer features low noise USB ports (as they are powered by a low amount of electric current) and the audio playback engine used (MPD) allows BitPerfect playback toward the external DAC. We used an Audioquest Carbon USB cable for this test. We used several sets of headphones, our faithful Sennheiser PX100, a Shure SRH-1540 and an Audioquest Nighthawk. The files we listened to were in FLAC and DSD format.
This headphone amplifier offers an absolutely exceptional sound. We have rarely heard such refinement and even the McIntosh MHA100 headphone amplifier is a step below. The Audio Technica AT-HA5050H is incredibly generous from the very beginning (without any break-in period) while staying incredibly neutral. When listening to it, you realise that only a small part of the sound is actually heard with lesser quality headphone amplifiers. The listener?s attention is not focused on one or two instruments or the artist?s voice, but on the contrary it is captivated by a plethora of micro-details masterfully extracted by the amplifier.
?L’amour est un oiseau rebelle? (FLAC 16/44) is delivered with palpable emotion, the space between Maria Callas and the choir is extended to the extreme. The voice of the diva fills the space in a unique way, without any dynamic compression. ?Fortes? are extremely realistic and the emotion is tangible. We stay speechless and we start wondering how we can possibly listen to lower quality electronics on a daily basis. In a different register, we completely rediscovered Serge Gainsbourg?s 69 année érotique (FLAC 16/44). The sound take and mix are outstanding. The violins on the right are full and the echo can be heard all the way to the far left of the sound stage, Gainsbourg sings in the centre with an extraordinary smoothness. The whole track is incredibly rich and simply magnificent. Everything we listened to was absolutely delightful.
Audio Technica AT-HA5050H- conclusion
One can only praise an amplifier as musical as the Audio Technica AT-HA5050H after listening to it. Absolutely every type of music and recording is delivered with an extraordinary amount of details and, most importantly, with a coherence beyond reproach. The sound is both extremely rich and simple. This is music with a capital M, regardless of the type of headphones used.