I recently reviewed the Beyerdynamic T1 Tesla headphones, which were more than a little impressive. Beyerdynamic was kind enough to send along their new A1 amplifier with the T1s, and it was one of the amplifiers I used for my testing of the T1s. In this capsule review, I consider the A1 itself.
To some degree the cat is out of the bag here. That’s because you can’t have the excellent performance that I found with the T1s when driven by the A1 if the A1 itself is mediocre. Sure, the T1 and the A1 might have offsetting errors, but that is something that mostly works in the realm of frequency response. If the A1 has high distortion or can’t drive high impedance headphones (the T1s are the highest impedance phones we’ve had in the lab), I would have heard it. But in any event the A1 sounded quite fine with the T1.
Since then, I’ve done more complete testing of the A1 with other headphones. Three things stand out from that work.
First, the A1 seems to have as much or more output capability than any amp we’ve had around (including the Woo WA22, PS Audio GCHA, Head Direct HA-1, Grace m902, and Peachtree Audio iDecco). This impression can be a function of gain or volume control taper, so I want to be clear that this is subjective. That said, the A1 has a sense of dynamic ease that is consistent with the observation that it drives all sorts of headphones easily.
Next, the A1 sounds a bit warmer than some other amps. I noticed this especially in comparison with the Grace m902 when listening to the Sennheiser HD800s. But, and this is a critical caveat, you need to read myarticle on the impact of headphone amp output impedance to really understand this. That’s because the A1 is a high output impedance amp (about 100 ohms), and such amps should sound different than low output impedance amps (like the Grace) on some headphones. On other headphones this difference will be minimal. So, I have to caution that this sonic attribute may or may not show up for you.
Finally, the A1’s treble region sounds a bit drier than that of some other amps. By this I mean that the amp exhibits a very small amount of grain on treble sounds, at least when used with some headphones. Through the Sennheiser HD800s, for example, I felt the Grace m902 headphone amp showed a little more treble “micro-smoothness” than the A1 did. That said, however, I found this difference less noticeable when listening through the T1, so some of this may be attributable to frequency response differences caused by the different amps highlighting certain specific attributes of various headphones.
I’ve kept this brief because I am concerned that too much of what we say about the sounds of various headphone amps can give the impression we are describing intrinsic qualities of the amps, when in fact we’re actually (and sometimes unknowingly) discussing amp-headphone interactions.
With that consideration in mind, know that the Beyerdynamic A1 is a very punchy-sounding high output impedance amp. If high output impedance works for your headphones, and you yearn for a lively but not edgy sound, I think you’d really enjoy the A1.
Beyerdynamics A1 Solid-State Headphone Amplifier
Accessories: Power cord, high-quality RCA cable, cleaning clot
Inputs: Two analog (RCA)
Outputs: One analog (RCA), one ¼” headphone jack
Output Impedance: ~100 Ohms
Other: Features ALPS volume control, analog (RCA) output remain live whenever amp is plugged in, headphone jack becomes live only when amp is switched on.
Maximum Amplification: 18 dB
Frequency Response: 1Hz -100kHz
Dimensions (H x W x D): 1.97” x 9.84” x 8.86”
Weight: 5.07 lbs.
Warranty: 1 year, limited.
56 Central Ave.
Farmingdale, NY 11735