Disclaimer: The A20 amplifier was sent to me by Beyerdynamic (site advertiser) for review. I was supposed to keep it 3 weeks but I’ve easily had it for 6 months. So first of all a big thanks, and sorry, to Beyerdynamic for the delay!
Beyerdynamic launched their more expensive A1 amp first before putting the A20 on the market. They also released the A200, a portable mini amp (an AK10 mod) a few weeks ago. I don’t think the A1 amplifier was very popular with audiophiles and I was quite surprised to see Beyer using A20 amps themselves at all their booths at the meets they visited.
As I have said on Headfonia before, the longer I am in this hobby, the more I like/appreciate the Beyerdynamic headphones with my favorites being the DT770, Custom One Pro and the T90. The first two I tend to use straight out of my DAP or with a portable amp (ALO/Cypher Labs/JDSLabs) but the high impedance T90 to my ears has always sounded best on an OTL tube amp like the cheap but great Bottlehead Crack for example. So seeing Beyer use this A20 as a standard amp for their full line-up got me very curious. And how would the A20 behave when used with other high impedance headphones like the Sennheiser HD650? And what about Orthodynamics headphones?
The last few months have been extremely busy and I just couldn’t find time at home to listen to the A20. I finally decided to smuggle it in to work where it could get a lot of air time. I tend to use the Cypher Labs Theorem at work lately, so I just took a 3.5mm to RCA cable with me so the Theorem can serve as the DAC et voilà: review time!
The A20 Unit
The A20, which is based on the A1 design, is developed for dynamic headphones from 30 to 600 ohm. It is a small solid state desktop amplifier using SMD Technology. Only measuring 164 x 212 x 55 mm it is leaving a small but heavy (1.64kg) footprint. It’s not the lightest unit around but the A20 first of all is a desktop amp and secondly it has an all-metal housing from brushed aluminum.
On the front, right next to the LED power button, you can find two (1/4’) in parallel connected headphone outs so you can connect 2 headphones at the same time. There is one really (good and quiet) smooth and light turning ALPS potentiometer so both headphone outs will get the same output level (however when you connect two headphones simultaneously you will hear the volume drop). On the back you have the RCA inputs and a pair of outputs. The input is directly wired to the output. That means no signal loss and you don’t need to power on the unit when using the output (to a power amp or to a pair of active loudspeakers)
The A20 has an impressive 100Ω headphone output and delivers 100mW@600Ω, 170mW@250Ω and 150mW@30Ω. These last numbers don’t impress but we all know it’s not just about the numbers.
I really like how it looks; it’s well designed, looks modern, elegant and doesn’t upset my girlfriend when I leave it in the living room near the couch. You can’t see any screws on the external surface either. It’s slick! Can it get any better? Well yes, it has to sound good, or even better: great!
Beyerdynamic says: “With the A 20 you will rediscover your dynamic headphones… The discrete output stage provides plenty of power even for high-impedance headphones while the dynamic, open and precise sound sets the A20 apart. The A20 supplies an impressively natural and transparent sound with excellent resolution and spatiality”. How could you not expect this to be a great sounding amplifier after having read that just now? Can it live up to the marketing talk?
The answer is easy and short: Yes it can. “Really?” you say, well yes I am very impressed with this amplifier. I did not expect it to sound this good. The A20 has a neutral balanced sound that may be is a tad tilting to the warm side, but only ever so slightly. This isn’t a warm sounding amplifier; it is very clear and fast sounding. Dynamics are very good and it overall is nicely musical sounding, managing to portray the details in the music as well. Great left-right separation too.
Bass is great. It is tight and fast with a good amount of body. Maybe even a little too much body for some or with some headphones but I found it just perfect, it doesn’t overpower the mids but it is very present. The mids section is where the A20 really shines: clear, smooth and musical mids with good body and lovely detail, what’s not to like? The treble section to me isn’t too bright but I can imagine it being a bit hot when using a treble liking headphone like the DT880 in example.
So is everything incredibly good then? Let’s be realistic, some things could be better. Sound stage and 3-dimensionality in example could be wider, deeper and better. There could be even more detail and air in the sound and there are amps with blacker back grounds on the market and there of course are more resolving amplifiers. But isn’t there always something better? The A20 is dead quiet till you turn the volume pot up 85% but you would be deaf by then.
Am I saying the amp is not good then? Au contraire my friends, the A20 overall sounds really good and it has an incredibly high toe tapping factor. It just carries you away with your music. I love it. If you’re not convinced, keep reading and do check out the conclusion below the headphone part.
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