Pros: Clean, transparent, detailed sound with enough power to drive anything from 32 ohm to 600 ohm with ease.
Cons: Would like more sparkle in the treble and other colors.
I got my Meier Concerto for nearly eighteen months ago. It has played faithfully and well with all the headphones I've used with it and I'm still happy with its sound in every way. It has since I got it been my reference amp when I have listened to potentially new amplifiers to my headphones.
It's always nice to listen to new gear and the Concerto is always fresh for a challenge from other gear once in a while. So I thought it would not hurt to try a new piece of gear to see if it can stretch the Concerto. The Concerto is developed by Jan Meier. Jan is an enthusiastic head-fi’er and founder of the one-man company, "Meier Audio" and developer of several great amplifiers through the years. The Concerto will hereafter try to bite spoons against an amplifier developed by Beyerdynamic. Beyerdynamic is one of the biggest players in the headphone homeland Germany, with a larger R&D department and the sales of cables and accessories is probably more than Meier's total revenue by several lengths. Not that I know anything about the figures for turnover ... - You get the picture... I am only guessing.
I have had an A1 amplifier in the house for a short period of time for approx. 3-4 years ago. My most recent encounter with Beyerdynamic A1 was at our local Danish Head-fi meet in the spring at HiFi Freaks in Esbjerg and I was surprised to rediscover its sound with the new Beyerdynamic headphones – especially the T1. I got an opportunity to buy a new Beyerdynamic A1 and I jumped in and figured I would see if it could compete with my Concerto as a good all round headphone amplifier. Concerto is at this point the best I have listened to so far in the price range and is my preferred reference. Now I know that I have not listened to everything but I have heard quiet a few amplifiers over the years.
I frequently switch headphones depending on mood and different music genre listening. Sometimes they are closed and sometimes open headphones. Most days I listen to jazz and classical sometimes blues, rock and electronic and on other occasions hip hop, dubstep, metal, funk, reggae .... Well... the only genre I almost never listen to is the POP genre. Therefore I do require very different headphones to meet the demand and satisfy me. Since I got a new set of Beyerdynamic T1, they were the headphones I use most. They cover probably 60% of my listening in my living room. The Sennheiser HD650 and Grado SR325i share the remaining 40%. But this is only at the present moment. If I know myself well enough this will change next month. So the amplifier I use at home has to be able to drive all sorts of headphones from 32 ohms to 600 ohms equally well.
Now most people would think that a set of 32 ohm Grado headphones can be powered by anything and that it requires much more power to drive a set of 600 Ohms T1's. But bear in mind that a 32-ohm headphone put a different load on the amplifier than a 600-ohm and requires more current to give the same effect and it can be as great a challenge to the amplifier if it is not designed optimally. Beyerdynamic states that the A1 is "maximum power" to the headphones 32 to 600 ohms.
The Beyerdynamic A1 headphone amplifier was launched in 2007 and has received good reviews most places and lately it received the price "Goldenes Ohr 2011" in Germany in the category of headphone amplifiers. So something may indicate that Beyerdynamic has a good product here that deserves more attention. It's not often a product is flavor of the month 4 years after it was launched but that is in a way what has happened to the A1. Normally it is only new products that receive that status. Nevertheless there has been more writing on the A1 in 2011 than I have noted since 2007. I asked Gunter Weidemann, Manager Technical Support at Beyerdynamic about what caused this and he is not in doubt. It is certainly a part of the reason that Beyerdynamic last year launched the Beyerdynamic T1. "Together with T1, its 600-ohm impedance and Tesla technology, A1 was rediscovered by the users."
Another reason causing the A1 sales figures to rise is that it has now also been launched in a 110...120 volt version. Previously it was only available in the countries using 220...240 volt. It opens up some new markets - including the United States. This probably explains why I have never read much about it here at Head-fi.org. Beyerdynamic has chosen not only to build a normal switch mode power supply into the A1, which can handle all voltages but the whole circuit is optimized for the specific voltage together with a special toroidal transformer for 110V and 220V respectively.
The Beyerdynamic A1 is hand assembled in Germany. It is something they always emphasize at Beyerdynamic and there is not the slightest doubt that the A1 is just as solid built as you can imagine. Even the volume-knob torque is perfectly nice when you turn it. This is a little detail that I cannot help but notice. Maybe I'm maladjusted because of my job. (where there are no analog potentiometers used in products for many years and when I ever use gear with analog potentiometers, it is always important that it feels like quality - maybe it's just me?) So no doubt that the build quality is top notch!
In the old days there was an orange version of A1. I doubt that there are sold many pieces of the orange version. Maybe it has even become a collector’s item today? It was not my favorite headphone amplifier based on looks – need I say more? Anyway, I could not help but wonder if they could build it in other colors in the future. Maybe they could introduce a future Manufaktur-version with other colors than grey? According to Gunter Weidemann, there are no plans in that direction when I asked him.
Mr. Gunter Weidemann also sent me a picture of a transparent A1. There you can see the toroidal transformer and 4 FET's on a massive aluminum plate. All prints are 100% non-SMD components and with wired connections and carefully selected components (which manufacturer does not carefully select its components if you ask them?). All this should, according to Weidemann lead to an excellent channel separation; L / R> 89dB.
There really is a HIGH gain in the A1. An amplifier designed to drive both 32 and 600 Ohm headphones often has a high / low gain selection. The A1 does not have any gain selection but still it's no problem. I can easily find a volume that is low enough to listen comfortably at SR325i and even with the T1 I can get dangerously loud volumes at 1 pm. With the HD650 I'm at my pain threshold by pm. 12 and at normal listening level at 8-9. So I can hardly imagine that there are people who have something to do with the volume button passed 1 pm. After that it continues a further long way and passes eardrum-flapping levels and I find it hard to believe anyone can use such high volumes. If you turn off the music and turn up to max then there is also some hiss and buzz, fueled up. So there really must be a lot of gain on the A1 when you get there.
I also note that when there is no music on, I can at around 12 begin to hear some background noise with the HD650. However, it is the maximum volume with HD650 on A1 and I would never be up there in normal use, so practically this noise does not exist when operating at normal listening levels. It only shows that this amplifier has HIGH gain with the pros and cons this gives. I have not tried any very sensitive IEM on the A1. It would be interesting if volume could reach far enough down low not to be giving too much hiss. I think it can because the volume decreases very slowly at the bottom towards zero.
That you can turn up the volume so high might indicate that the A1 has plenty of horsepower under the hood. It is also quite clear when listening to music through the A1 there is plenty of everything. Lots of bass, deep firm and calm. Lots of presence in the mids and treble are soft and do not in any way sound shrill. The sound is incredibly clean and transparent. Hmmm ... (We have heard that before) Well this IS how it sounds – these words are not just the usual platitudes that are always mentioned when someone has to describe the sound of an amplifier.
If the A1 in any way had added anything else into the music than there is, I would have been focusing on this. The thing is that if there is something to focus on it would be the strength of the A1 and that is precisely this ability to let the music flow in crude volumes into any headphone being connected to eh A1. Every kind of headphone, high or low impedance, is harnessed to its full potential. The A1 simply takes authority over the T1 as well as a set of Grado’s in a way so that they reach their full potential in dynamics and speed, punch and impact. Even at low volumes the A1 sounds just as transparent as with medium volume and not constricted as some amplifiers can do when they are not allowed to play louder.
When listening to vocal music, vocals sound real, natural and intimate. On "In a sentimental mood" of Cæcilie Norby’s live CD London / Paris, the room is nice and transparent and the voice is clear and nicely rendered. The underlying bass gets a very nice weight to it. The A1 has a natural soundstage and no artificial space but a realistic depth, width and height depending on the recording sessions.
All in all there is nothing in the sound that draws my attention. It simply gets out of the way and lets the music flow. I have searched and searched for a weakness in this amplifier through many hours of listening and I have changed headphone many times and listened in various genres. If I were to wish for anything it would be that the highs would be a little livelier and there was a little more sparkle in the high frequencies. I would never have asked me if it was not because I was used to Concerto, which is slightly brighter in its sound. I have also switched back and forth between A1 and Concerto to find the nuances that make the difference between the two. Comparing the two has been very easy since A1 has a loop out (RCA in directly to the RCA out) which is also active even when A1 is off. So there is really a direct loop through. So I've been able to connect both the Concerto and the A1 to my DAC at the same time and therefore easily and quickly just switch amplifier by simply plugging the headphone into the other amplifier.
Beyerdynamic A1 in compared to the Concerto
It says more about the A1's sound when I compare it to my own reference. I also hope that it makes better sense for the reader to grasp what kind of species the A1 is and how it sounds if I made some comparisons to the Concerto. The differences between the sounds of the two amplifiers are so small that I really need to listen carefully - and it is in my ears very distinguished credentials for the A1. Therefore, what I write below is small exaggerations to describe those differences better. These really are two neutral headphone amplifiers and neither of them colors the sound much in any direction. This probably makes the range of headphones that will pair well with both of them larger.
There is little more throughput in the music with the Concerto - just a bit more, not much. The Concerto has a little more treble and a little more micro detail. The Concertos treble is a little bit to the lively side and it is probably the biggest difference in relation to the A1. A1 stays always on the clean side where the Concerto is a little "naughty" in the treble.
With A1, there is more weight in the sound and more body behind the music where the Concerto is a bit brighter and lighter. The somewhat fuller sound from the A1 is something that suits headphones like T1 very well. Vocals get some meat on them and you can almost feel the sound have a well-defined physical weight. T1+A1 is an absolutely amazing pair on some recordings.
Can the Beyerdynamic A1 harness all kind of headphones from 32 ohms to 600 ohms - YES. It can with ease. I feel it has full control over both a set of T1 and a pair of Grado’s. The Grados sounds just as controlled as when they play on the best solid-state amplifiers I've heard them – except a Beta22 I once heard them play from. Also I would almost think that the A1 can drive a set of 1000 Ohms headphones without problems taking in consideration the gain factor it has and which I never really feel like I utilize – even with the T1. Whether it can run a set of 18 Ohms super sensitive IEM without hissing noise and I cannot say anything about because I do not have such to test it with. However Beyerdynamic says it drives 32-600 Ohm and so it does. My guess is that you can reach a very low volume with the ALPS-pot in order to get a comfortable listening volume level even with sensitive IEM’s.
Is A1 a better amp than Concerto - NO ... but it is not worse either. These are two - to my ears - very good headphone amplifiers and I could easily live with the A1 instead of the Concerto. They both do what I want to have a headphone amplifier do. They have to be able to function as an all-round amplifier that will drive all my headphones equally well to all the genres I listen to. A1 definitely deserves to be rediscovered and get another chance. Especially if it is combined with a set of T1! It delivers fantastic sound and will offer countless hours of music enjoyment to listeners with varying headphones and music-genres.