Beyerdynamic A20 Amplifier Review

Beyerdynamic A20 Amplifier Review

Elegant in it’s simplicity, the Beyerdynamic A20 is a heavy desktop amp perfect for your headphone use.  Priced at $599, it’s neither too expensive nor too cheap, as amplifiers go.  But what features does it offer, and how does it sound?

Beyerdynamic A20 Amplifier Review

Beyerdynamic A20 Amplifier Review


The A20 features a body of brushed steel, with a plastic top plate that works equally well holding a pair of headphones or a tall, cold one.

On the front of the unit, there is a power button, two 1/4” headphone jacks, and a volume adjustment knob.

The back of the amp is home to RCA input and output jacks, as well as the power supply.


Dimensions 164 x 212 x 55 mm
Frequency range 10 Hz – 100 kHz (-1 dB)
T.H.D. 0.01 % at 170 mW / 250 Ω
Maximum output power 170 mW / 250 Ω
Unweighted signal-to-noise ratio > 100 dB (unweighted)
Channel separation > 80 dB at 1 kHz / 250 Ω
Headphone outputs 2 stereo jack outputs 6.35 mm (1/4″) in parallel mode
Analog inputs 1 pair RCA
Analog outputs 1 pair RCA
Net weight without packaging 1640 g

As you can see from the specifications, the A20 offers an impressive frequency range, and works optimally with headphones up to 250 ohms.  However, in working with this amp, I’ve realized that it can easily handle anything up to 600 ohms, or you can pair two 250-ohm headphones at once, without pushing the A20 beyond its limits.


Thanks to its solid state design, the A20 offers a crisp and detailed sound sure to benefit just about any listener.  There’s no noise floor, or if there is one it is so low as to be imperceptible to me, despite my best efforts to detect it.

While the articulated sound with be of benefit to most listeners, it could be a little too detailed and articulate for some older, less-clean recordings.  In other words, while it offers a revealing experience, this amplifier could be a little too revealing.


It stands to reason that the Beyerdynamic A20 amplifier would pair well with a Beyerdynamic headphone especially the top-of-the-line T1 2nd Generation, or the penultimate DT1770 Pro.  But I’ve also found this amp to be well-paired with Sennheisers, especially the HD600 and HD650, which benefit from the enhanced detail to result in a razor-sharp sound that cuts through your ears to deliver every detail, clean and crisp.

As sources go, the A20 would be equally at home plugged into your iPod or computer.  The inclusion of an RCA output on the back of the unit allows the use of speakers, so this headphone amp could potentially be that one-and-done desktop solution.

Overall Impressions

If I had $599 to spend on a desktop amp, and I wanted clarity and detail, the Beyerdynamic A20 would be at the top of my list.  As I mentioned above, this isn’t the most forgiving with less-than-good listening material.  Old recordings, in particular, may suffer from the wealth of detail offered by this amplifier.  For everything else, though, the sound is exemplary, and we highly recommend you give this amp your due consideration.

If you’d like to take the Beyerdynamic A20 Amplifier home, snag it at the lowest price on Audio 46 when you use discount code “majorhifi” during checkout. This amp also retails at a competitive price on Amazon.



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Carroll is a headphone junkie residing in Brooklyn. He's a huge fan of Grado, UK hip hop, and the English Language in general. When not testing audio equipment or writing, you'll find him taking photographs or fiddling with circuit boards. You can contact him at