Our tests on the Beyerdynamic 200 p DAC coincided with recent tests we?d carried out on the Beyerdynamic T5p headphones, and the Qobuz Hi-Fi Guide can?t recommend these enough when used together with the amplifier.
The device at hand is a portable DAC / headphone amplifier compatible with computers, Apple iDevices equipped with the lightning cable, as well as certain smartphones on Android (check the end of the article for a full list of compatible products).
It can read digital audio files up to 24 bit 96 kHz, and its integrated battery allows on-the-go use: this is great news since it won?t be draining the smartphone?s battery as it amplifies its sound. A 200 p is very similar to the DAC amplifier for AK10 headphones from Korean manufacturer Astell and Kern, whose independent High Definition audio readers, including the AK240, were a true success amongst passionate audiophiles wanting to transport and listen to their music everywhere in the best sound quality. In addition, it?s worth noting that the A 200 p comes with an equally compact leather case.
So what?s the product in a nutshell?
The 200 p model is essentially a compact box with 55 x 55 x 13 mm dimensions, with a large silver disc in the middle: this is used to control the volume, with a tiny red LED light flashing to show increase and a blue one to show decrease.
On one of the sides, there?s a little switch that allows you to switch the device on and off, with an additional locking function that prevents altering of the volume.
On the opposite side you?ll find a standard 3,5mm headphone jack, and on another side, three small buttons that allow music playback, pausing and skipping forward and backward. You can connect to one of the three devices: computers, certain Android smartphones or iDevices. All require the micro USB port on the opposite side of the headphone jack, with three separate cables provided to link the A 200 p to any of these devices.
What?s in the box?
If you take a look underneath the lid, you?ll discover the Lithium ion battery that produces 3,7V and has a capacity of 1100 mAh. On these sides you?ll find a 3,5mm mini headphone jack, the mini USB connector, as well as other components.
You?ll find the rotation system of the metallic disc on the reverse side. It rotates and slides down a plastic surface by dragging an Alps SRPG40 optic encoder, which can be seen in the image below.
This encoder generates two asynchronous pulse trains (in order to detect the direction of rotation based on the first pulse train), and those which are decoded and which in turn raise or lower the volume.
The maximum volume setting depends on the device that you connect to the A 200 p: 135 with an iPhone 5, 230 with an Apple computer, and up to 230 with a Windows PC (the volume is synchronised with that of the PC, whereas it is determined by the A 200 p when used with an Android smartphone).
It?s a powerful system with configurable blocks and low consumption Cypress CY8C32 chip (see below) certified full speed USB2 with a (CPU) 8051 microcontroller that controls the interface and the management of digital audio signals from the USB connection (we?re quite certain that it?s going to be responsible for the global management of all electronics soon?).
It?s worth noting the presence of a Maxim MAX889 DC-to-DC converter to the right of the circuit. This circuit creates a negative tension of the same amplitude as the positive one, in order to power the analogue part, the filters and the headphone amplifier, thereby avoiding the need for the capacitors to colour the sound and reduce the bass?s bandwidth from the headphone output. At the bottom left you?ll find the Digital Analogue Converter, a Wolfson Microelectronics WM874O model that supports input data word lengths of up to 24 bit and sampling rates up to 192 kHz, with differential voltage outlets.
The signals from these outlets are filtered and differentiated by the components located to the right of the WM8740, visibly comprising of operational amplifiers that we weren?t able to identify.
Next comes the amplifier for the headphone entirely realised using discreet components, like the ?huge? Hi-Fi amplifiers which allow the the manufacturer, unlike the amplifier in the form of an integrated circuit, to choose the desired structure and to master all the parameters of this amplifier.
Time to put the gadget to the test!
Whilst we enjoyed scrutinising every aesthetic and functional aspect of the product, we took even more delight listening to it. Although the silver disc controlling the volume is a nice addition, it might take some getting used to at first because it can be quite slippery. It?s also worth noting that the output level is limited (to conform with regulations) though it can be deactivated.
That being said, we found that the sound quality delivered by the A200 p is simply superb, and to achieve this we used Beyerdynamic Custom One Pro headphones, given its superior bass range compared to the T5p model.
When listening to Dvorak?s ?Allegro? by Ivan Fischer and the Budapest Festival Orchestra in Studio Masters 24 bit 96 kHZ quality ? a pretty challenging piece for any audio device to get totally right ? the A 200 p didn?t falter for a second and proved itself to be a robust piece of material. The timpani sounded pretty good with a triangle that?s refined and chiseled; on the other hand, the drum section and the woodwind section were distinctly average.
We also tested the product with Katy Perry?s ?Roar?, and we didn?t feel the need to turn up the volume to ridiculous levels to raise its bass. It also did justice to Stromae?s vocals on ?Papaoutai? and ?Moule Frites?, from his ?Racine Carrée? album, which sounded simply exquisite, along with an excellent bass accompaniment.
For these tracks we used the Foobar2000 audio player on PC, and then tested with a Sony Xperia smartphone and iPad. In both cases, all we needed to do was plug the device into the A 200 p with the required cable (remember that there are three!), stick in the headphones and hit the play button. We couldn?t have imagined anything simpler.
Original article by Philippe Daussin
Translation by Amy Clarke