Review: Rein Audio X-Phone headphone amplifier
May 1, 2013 at 10:57 AM Thread Starter Post #1 of 1


500+ Head-Fier
Mar 3, 2011



The new X-Phone shares many of the features of the X3-DAC in finishes and construction as I pointed at the start is the first incursion into the world Rein Audio amplifiers for headphones.
Feels just solid and well built, giving the feeling that it is a product made to last many years. The design is simple and elegant, full finish black color nicely complements the lines of the X3-DAC, making them a very eye catching combo in our table or desk.
It has a pair of RCA inputs, Rhodium plated equally in the rear and a single output Neutrik Jack 6.3 mm headphone brand, along with an ALPS potentiometer handled through a generous aluminum volume knob and very accurate .
As construction at the circuit level, Rein Audio has tried to incorporate the highest quality components to try to get the best sound.


• The X-Phone is a high-quality headphone amplifier which
has been developed and designed for headphones with a
nominal impedance between 30 and 600 ohms.
• The special circuit design provides an impressing natural
sound reproduction with an excellent resolution and spatiality.
• The powerful mains adapter avoids dynamic distortions.
• Although we have developed the X-Phone for use with our
Premium Line headphones, you can use also headphones of
other manufacturers.
• The X-Phone is ideal for very different impedances, because
the high output impedance at the headphone socket ensures
that the range of the volume potentiometer remains ideal even
for low-impedance transducers.
• Intelligent circuit design with microcontroller capable of 96 kHz
• Volume control with high-quality ALPS potentiometer
• Large dimensioned toroidal core transformator for high fidelity
of impulse and dynamics
• One stereo inputs for sound sources
• LED to indicate the active signal input and power on.
• Rhodium plated audio sockets for perfect signal transmission
Input impedance: 50 kΩ
Maximum amplification: 18 dB
Frequency response:1 Hz - 100 kHz (-1 dB)
T.H.D.: 0.001% at 170 mW / 250 Ω
Channel separation:> 89 dB
Output power:100 mW / 600 Ω | 170 mW / 250 Ω | 150 mW / 30 Ω
Unweighted signal-to-noise ratio:> 100 dB
Output impedances: 100 Ω headphone output
Power consumption: < 15 W via internal, controlled power pack
Audio connections: Rhodium Plated Headphone socket, Audio inputs
Mains power input: 110 - 230 V AC, 50/60 Hz (swtichable inside)
Dimensions: 185 x 255 x 60 mm
Weight: approx. 2.3 kg



In an attempt to make an evaluation as fair and accurate as possible I’ve tried to use a wide range of headphones with the X-Phone, like the Sennheiser HD800, Sennheiser HD650/600, Hifiman HE-400, AKG K550 or Sennheiser Momentum. Always matching it with the X3-DAC with an excellent synergy which I appreciate a lot. Interconnecting cables used have been a pair of  WireWorld Solstice RCA.
If you look at the specs you probably have called attention about the 100 Ohm output impedance.
A priori  the performance with low impedance headphones will be rather than ideal, and in part the theory is true.
After doing some listening sessions with headphones like the AKG k550 or Sennheiser Momentum and trying to get a good resultant sound without success, I concluded that the X-Phone is not a suitable amp with low impedance dynamic headphones.
The sound with the Momentum becomes fast and completely free of background noises, but the middle region becomes retracted and loses much of the body as well as a fall in the sub-bass response.

After this little disappointment, I tried it with higher impedance headphones and with more requirements for an optimal performance. This is the case of the trio Sennheiser HD600, HD650 and HD800.
The sound is much better in this case. With this type of headphones I can really appreciate the X-Phone qualities, characterized by a high detail, as the X3-DAC, particularly in the highs whith a great extension in every song.
I would not define it as warm headphone amp , is more on the neutral side. Rein Audio certainly has considered two factors designing this amp, clean and definition.
The brand itself incorpored a microcontroller capable of handling frequencies of 96 kHz, for me this is reflected in the scale ability offered by this amp with a quality DAC, such as the X3-DAC, along with lossless files in high resolution.
Powering my Sennheiser HD600 I find myself unable to move more than 11 o’clock with the volume potentiometer, so power is not a problem. The resulting sound is very lively, with a good body in the bass and mids section, with a very natural and prominence voices mitigating that little "veil" on the HD600/HD650, and I must say that generally prefer the sound of the first.

X-Phone and Sennheiser hd800


Special mention requires the great synergy between the X-Phone and the Sennheiser HD800, which I enjoyed a few days, and certainly this are the most enjoyable headphones that I tried with this amp.
The Rein Audio X-Phone seems to be designed to accentuate some of the Sennheiser HD800 characteristics in terms of scene and like these headphones I would define it as very large and airy.
Voices sound very clear, clean and with a great articulation. The decay is greatly favored with this amplifier, providing also an organic touch to the middle section.
The soundstage pairing with the HD800 is such big that I found myself turning my head thinking that the sound came from my own room and not from the recording I was listening…
Talking about the bass, the X-Phone is able to give you an extra touch of body  and a better punch with the HD800. Something that certainly helps to humanize the sound of these headphones, which at times can sound a bit clinical due the high level of resolution and detail.
Making a brief comparative moving the Sennheiser HD800, the X-Phone against Burson Audio HA-160 that also I have, I honestly prefer the combination wiith the Rein Audio!
In terms of detail I would say the X-Phone is above the Burson amp, the last one is maybe more musical and has better transition from the middle to the highs, but on the other side it also has a more aggressive sound, and I think that for the Sennheiser HD800 it could not be as nice as the X-Phone is.
X-Phone has a serious sweet sound using this headphones with a greater extension, which provides an extra touch of warmth to the Sennheiser, resulting a more "analog" sound than the Burson.
Considering that this is the first headphone amplifier by Audio Rein, is definitely a product to keep in mind for high impedance headphones.  For the lucky Sennheiser HD800 owners I must say them  just take a chance on this amp, since, despite having an affordable price (399 $ special offer right now) I found it really really nice with this headphones and also with the HD600/HD650.
It can be purchased through the Rein Audio website with an excellent 399$ special price! 
Thanks to Jason, from Rein Audio for his fantastic service and attention all the time.

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