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My experience with headphones I didn't like as much with the Phasemation was different that usual. Usually if particular cans don't work with a given amp it's quite simple. The sound is unacceptable and that's the end of it. With the Phasemation the character of the sound changed differently with each model. The AKG K701 no longer sounded warm or romantic, the HiFiMan HE-300 no longer had the same nicely extended treble and soft bass it usually has. On the other hand the AKG didn't sound plastic which happens with certain amplifiers. The Phasemation did its best with any can I threw at it. It never gave up, just delivered the best possible sound from any particular setup, leaving it up to the listener to proclaim judgment.


In the past headphones were always treated as complete product delivered as intended from beginning to end by the original maker. Plug to drivers if you will. Most headhpones had no provision for replacing their cables. And for the longest time nobody figured to experiment. But in recent years headphones have enjoyed a mass revival with the rise of computer and portable audio. Some cable companies jumped into this movement to offer replacement wire harnesses. One of those is Oyaide from Japan. Their cables are made of ultra-fine PCOCC-A conductors where twenty 0.08mm wires are bundled and three such bundles become a geometrically-stable lead. The plugs are of Japanese origin too and made of RoHS-compliant brass. After careful machining there's silver (inner) and rhodium (outer) plating of the contacts. The other end of the cable can be terminated in various plugs. I chose the mini XLR/TRS version which AKG use for their Studio Series models which for this review accommodated my K271 Studio.


When selecting headphones for the Phasemation EPA-007 test, I decided after a short listening session not to use the AKG as it lacked resolution and had a muffled treble. These cans are not easy to drive and usually work best with studio equipment. But I tried them again after I replaced their stock leash with Oyaide. Most of us agree that cables modify the sound of speakers or electronics but when it comes to headphones not many people try to replace the stock cable with some alternative. They don't seem to believe it would work. They really should try! The Oyaide was clearly better - more transparent, better resolution. There was more treble energy to better show what was going on in this area. Before it had sounded muffled and plastic. Now it became more palpable, instruments gained body and depth which previously hadn't been visible. It's no exaggeration to claim that this cable swap improved performance to now compare favorably with more expensive stock-wired AKG whilst retaining what I already liked about the Studio K721. Here a replacement leash isn't optional but mandatory (the price for this cable in Poland is 300zł/2.5m).

Summary. In general one might classify all headphone amps into two categories – warm and cold. In the first group I count models from Leben, Yamamoto, Heed, Benchmark and Pro-Ject, in the second models from Erzetich Audio, SPL and Ear Stream. In each case their designer made some a priori decision which resulted in an either warm or cold sound. The EPA-007 could seem to belong to the second group but it can be adjusted to sound more like amps from the first group. It offers an amazingly clear sound which also describes members of the first group but can deliver the depth of each image like 'cold' amps do. It has a very fast sound and both frequency extremes show great resolution. In turn the midrange isn't as rich, dense, palpable and resolved as my tubed Leben but no other headphone amplifier has ever equalled the Leben in these qualities. Resolution with the Phasemation can be further improved if we use balanced wire harnesses and plug each channel separately into the amp. I tried that with the HE-6 and had to admit that it was the first time ever that these had selectivity and resolution comparable to the top Stax electrostatics. In both cases I still lacked some bass extension and slam but that's how electrostatics and HE-6 in balanced connection sound over the Phasemation. It's an exceptional headphone amplifier capable of working with all headphones.

Review methodology. This headphone amp was reviewed in an A/B test with both A and B known. The reference amp was the Leben CS-300 XS [custom version] with a Marantz NA-11S1 file player I'd reviewed for Audio which is equipped with a very good headphone amplifier. I used three sources all with balanced outputs: the Ancient Audio Lektor AIR V-edition CD Player, the Marantz and a Kuzma Stabi XL2 turntable with RCM Audio Sensor Prelude IC phono stage. The amplifier was placed on an Acoustic Revive Hickory wood platform and used a Power Reference power cord of the same brand. Additionally I used Finite Elemente Ceraballs to replace the standard feet. To connect HiFiMan cans in balanced mode used an Oyaide HPC-X62 cable. At the time of this review an alternate cable from Acoustic Revive was unfortunately not available.

Design. Headphones amplifiers are usually quite small unless we talk regular speaker amplifiers equipped with a headphone circuit/output as an additional feature. Examples of such amps would include the Cary Audio CAD-300-SEI, the Leben CS-300 XS/CS-600, Linear Audio Research IA-30T and the SPL Phonitor 2730. Most dedicated headphone amplifiers are rather small in size since they don't need to put out tons of power. The Japanese Phasemation EPA-007 fits that profile. It measures 220 x 57 x 234mm and weights 2kg. The chassis is made of aluminium and the front panel gets some extra thickness. It sports three knobs, two toggle switches and two 6.3mm outputs. The largest knob is a volume control, the smaller ones set 'damp' from soft to hard and adjust impedance to below 200Ω, 200-500 and above 500Ω. One toggle switch changes gain. For cans with <100Ω impedance we should chose low, for the rest high. I learnt during my listening sessions that for ultra-low impedance cans like HE-6 the high setting was best. The other switch decides whether signal is delivered to both outputs (for balanced headphones) or only to one of them. That's because the EPA-007 is a fully balanced device. To use its full potential one should use cans with separate cables for the left and right channels terminated in 6.3mm plugs. There are two sets of inputs - XLR and RCA. I definitely preferred the former even with headphones terminated with a single plug. You should take into consideration that input impedance is not too high, just 10kΩ, so you need to chose your source carefully. On the back panel is a IEC power inlet with the mains switch. There is a small LED indicating whether the device is on. The amplifier sits on very small plastic feet that should be replaced as quickly as possible with something more substantial.
opinia @highfidelity.pl

Specifications according to the manufacturer:
Input impedance (RCA/XLR): 10kΩ/20kΩ
Headphone input impedance: 16-600Ω
Frequency response: 20Hz–100kHz (-0.5dB)
Noise: 50μV
Channel separation: -90dB
Power consumption: 1.5W
Dimensions (WxDxH): 220 x 57 x 234mm
Weight: 2kg

Phasemation website