ASR Emitter II Exclusive with battery power pack – High end integrated amplifier

Review: In terms of workmanship, concept, design and reliability, the ASR Emitter II Exclusive is the most impressive chunk of amplifier

If someone has been building amplifiers for over 40 years, then they can tell something. Or even better: let your products speak for themselves. If you are technically interested and happen to have Friedrich Schäfer – founder of ASR Audio Systems and head of the currently ten-strong team – on the phone, you will know what I mean. If you take a closer look at one of his amps, the same applies: the design language alone is extraordinary and the variety of (optional) features and setting options is surprisingly large for a “mere” stereo integrated amplifier. In the case of our ASR Emitter II Exclusive with battery power pack from 17,500 euros, without battery power supply 14,500 euros), the word integrated amplifier goes hand in hand with four components that could each be independent hi-fi devices in terms of dimensions and weight: the actual amplifier is powered by two external power supplies for the output stages and a battery power supply accompanied for the preamp section.

Far be it from me to ring in test reports with “preliminary honey-on-the-beard brushing”, but when the ASR quartet is finally freed from its boxes in the starting position in my listening room, I spontaneously ask myself whether that’s possible could be the most fascinating devices that have ever been with me. But slow down – I hadn’t even heard a single note yet.

Show time

The light show alone behind the semi-transparent (the emitter amplifiers are all also available in fully transparent cases) eight millimeter acrylic glass front: no, not a glaring Las Vegas style, but like little outdated-looking labeled lamps that reveal, for example, whether the battery power pack is currently in charging mode or whether the power amplifiers are still bored in eco mode. The ASR Emitter II Exclusive exudes a cool steam-punk charm. If you want to experience the entire arsenal of lighting elements bundled in action, you can self-test the amplifier using the button on the inside and the multi-stage, left rotary control on the outer front – in the presence of a specialist, of course.

ASR Emitter II Exclusive - Display und Status-LEDs auf der Front

Speaking of “lamps and tests”: Various colorful LEDs also shimmer up through the acrylic glass cover like small stars in the night sky. But they don’t just want to be pretty, but also display operating voltages and functions in a very tangible way. In the event of a malfunction, users can send photos or a short video to ASR in order to receive an initial diagnosis and assistance. The large 42 mm LED display on the front is also meaningful and leaves no doubt about the selected volume value even at a greater listening distance.

Blick durch den Acrylglas-Deckel des ASR Emitter II Exclusive

The high-quality Harting plugs with their indestructible metal bodies on the outputs of the three external power supplies are absolutely modern (or better: timeless), but they also remind me of the past – namely the 80s and my electronics apprenticeship in the industry. The three associated lines then lead directly into the interior of the ASR Emitter II without any further plug connection.

I don’t want to linger too long, because touching is better than reading: It doesn’t matter whether it’s network connections, cinch sockets (WBT, Cardas, Clearaudio, … are available), WBT loudspeaker terminals (next-gen copper or silver) or the metal rotary controls on the font – Mechanically, the ASR Emitter II Exclusive radiates a quality that is anything but usual, even in its upper price range. Do I hear a question over there on the left? Of course, the central volume control has mass and rolls nicely when you nudge it.

ASR Emitter II Exclusive - Harting-Stecker

Is there anything to complain about in terms of processing? Well, the fact that the Emitter II wasn’t designed in California can be seen if you look really, really closely. It won’t suit everyone’s taste. Certain tastes all the more so – like mine, for example. Hmm, I find the heat sinks on the sides to be a bit too standard, especially since they ring audibly when you flick them on. However, this can easily be remedied with special heat sink dampers that ASR offers.


ASR Emitter II Exclusive - Innenansicht

If you loosen some of the upper screws hidden between the cooling fins, the acrylic cover can be removed. And discover a beautiful circuit board layout, the assembly of which was done in the classic way using the through-hole method and not via SMD. The channel-separated construction and the symmetry of the layout on the gold-coated circuit board with its 105-micron conductor tracks are immediately apparent. Even non-technicians will surely find this circuit aesthetically pleasing. Whereby, I say it to be on the safe side, symmetry here has nothing to do with a fully symmetrical circuit design (each channel is routed twice): Incoming XLR signals are correspondingly asymmetric with the ASR Emitter II Exclusive.

Ten power MOSFETs in a push-pull arrangement work towards the speaker terminals per channel: 2 x 280 watts at 8 ohms and an output impedance of less than 10 milliohms are definitely a statement. ASR Audio Systems also promises load stability of up to < 2 ohms. So the issue of “difficult loudspeakers” should be over for owners of an ASR Emitter II Exclusive.

ASR Emitter II Exclusive - IC mit Messingklotz

Emitter owners can put their dexterity to the test on the mouse piano: there are three rows of DIP switches per channel inside the amplifier to adapt the electrical conditions and the sound of the Emitter II to the devices being played and ultimately to your own listening taste.

ASR Emitter II Exclusive - Hochfrequenz-Kompensationsschalter

The two high-frequency compensation switch rows, each with six mini-switches, are used to influence the degree of negative feedback in the high frequencies. The more dips are “off”, the “faster” the transient response. This should make the sound fresher and a little more aggressive in the high frequencies. If you like it softer and rounder, turn the dips “On”. We’ll come back to this feature briefly in the sound section of this test.

It can be even more extensively hammered into the mouse buttons: one row of dips per channel for cinch and XLR signals allows the input impedance to be adjusted. The more microswitches are “On”, the lower the impedance , which normally leads to a quieter sound. The usual factory setting for the cinch inputs is all four dips off (22 kOhm). If you activate all dip switches, the input impedance is reduced to 280 ohms. With the XLR inputs (two dips) you can choose between 1 kOhm and 10 kOhm.

ASR Emitter II Exclusive - Dip-Schalter für Anpassung der Eingangsimpedanz

Power plant tour

With so many setting options, one or the other reader will definitely be pleased that the Emitter II drives fully automatically in other places. The battery power supply with its huge filter capacity ( 1385520 μF) and its six Yuasa batteries can be permanently connected to the mains. Depending on the fill level, the charging process is automatically (de)activated. Without a network connection, a fully charged battery would be sufficient for around 100 hours of operation. According to Friedrich Schäfer, the batteries themselves should be replaced every six to seven years.

In the two power packs for the output stages of the ASR Emitter II Exclusive there are then – logically – no batteries, but two “Philbert jacket cut” transformers each, each of which is specified with an apparent power of 700 VA. Thanks to the optimized core cut, ASR gives this type of transformer better impulse stability than toroidal transformers and a similarly good level of efficiency. The total of 957520 μF filter capacity will probably not harm a certain impulse stability either.

ASR Emitter II Exclusive - Netzteil mit „Philbert-Mantelschnitt“-Trafos

The topic of “cheeky little lamps” has already come up above and is also obvious with the power supplies: Again, it’s not (just) about decoration, but in particular about a status display and initial error analysis. Conveniently, one can read what is missing from the patient’s face. And the healthy, what he’s doing right now and whether he’s in a normal mood at the moment or a bit eco. The latter is the case when the left rotary control on the front of the ASR Emitter II Exclusive is set to position 1 – or to position S (standby) and the amp is brought to life with the included remote control. The two transformer-armored power supply units then treat themselves to around 50 watts of no-load power consumption.

ASR Emitter II Exclusive - Diagnose-LEDs am Netzteil

Eco mode is recommended for very sensitive, high-efficiency loudspeakers or if the Emitter II is simply supposed to amplify the TV sound and dynamic trills are running anyway. Or just for background music. However, anyone who uses electrically demanding loudspeakers such as my Wilson Audio SabrinaX and wants to listen to music in a concentrated manner should switch to normal operation (around 120 watts of no-load power consumption) in order to exploit the full sound potential of the Emitter II Exclusive. Important: To do this, you must first activate Eco mode, then wait for the short countdown and only then set the control dial to position 2. Without this detour, the amp remains ecologically true to itself even in position 2.

ASR Emitter II Exclusive with battery power supply: Sound test & comparisonsASR Emitter II Exclusive - Ein-/Aus-Schalter

External power supplies, 2 x 280 watts of power at 8 ohms: there should be a lot going on in terms of control and dynamics, right? Absolutely! As the intro of “Touch” on the album Awake , one of the late works by the Belgian electronic musicians The Klinik , proves: The pulsating sequencer and the cold, humorless beats are rhythmically among the driest that my record collection has to offer, that has something of it pure square pulses. The Emitter II Exclusive cannot be softened here, nor can my pre-end amplifier combination of Funk MTX and Bryston 7B³– and doesn’t bat an eyelid even at deafening levels. My stereo power amplifier Norma Revo PA 150, at least 2 x 150 watts strong, then wupps such dynamic swings a little less abruptly and jagged – although the differences in such music are more for the record than really relevant to the listening pleasure.

I find the differences that come to light between the two muscular men and the otherwise wonderfully musical Norma power amp to be more decisive when densely arranged, “massive” music – such as at times in “Last Known Surroundings” by Explosions in the Sky (album : Take Care, Take Care, Take Care) – comes onto the scene and my Wilson SabrinaX, which is not exactly undemanding electrically, forms the front end. Here, the higher load stability of the ASR emitter and my Bryston blocks contributes to an even more energetic, unmistakably defined and ultimately more impressive wall of sound, which simply pushes you even more into the listening sofa.

The last bit of pressure

ASR Emitter II Exclusive - Anschlüsse auf der Rückseite

Yes, in terms of control and lack of coarse dynamics, the ASR Emitter II Exclusive does exactly what you would expect in its higher weight and price class and is in no way inferior to dedicated power amplifiers. What he saves a little bit, however, is the last bit of pressure underneath: This is how the bass drum in Pelicans , which is set to every second quarter beat, sounds over my Funk/Bryston team“Midnight and Mescaline” (Album: Nighttime Stories) a tad louder, even fuller. To classify this unequivocally: I wouldn’t describe the ASR as “slim underneath”, when listening to it, associations like “still neutral, but elegantly discreet” come to mind. But of course: If you are primarily looking for a pornographic low-pitched orgy, you will definitely find more extravagant erotic actors in the price range and below.


With the ASR Emitter II Exclusive, the joy blows from a completely different angle: If I insert the album Inland by the French pianist Vanessa Wagner , the music touches me in a way that I first have to understand. It sounds more haunting, catchy, yes: somehow more sensual when it comes to the ASR Emitter II Exclusive. The connection to the music is actually a bit more intense than with my Funk/Bryston combo. But why? It’s not due to the dynamics – the two solutions don’t take anything away here. Stronger timbres I can’t make out a warmer tonality either. Although, timbres… Doesn’t the piano contrast with an even purer tone from the background? And doesn’t the latter seem even “calmer”, even “blacker”? Yes. When it comes to analytical, intellectual comparison listening, it’s not that big of a deal, especially since my amplifier combo also produces a very pure sound pattern. The ASR succeeds in the emotional appeal of letting go and dropping into the music in a somewhat more captivating way. The feeling of “authenticity” is stronger.

ASR Emitter II Exclusive - Akku-Netzteil-Anzeige

I have a similar experience with Get Well Soon ‘s “That Love” (Album: Vexations) .. Konstantin Groppe’s voice is captured so directly that the quiet sounds of lips and tongue are almost visible. Surrounded by whispering guitar, some piano swabs, a drum brush and delicate hi-hat hissing. And even if several instruments are on the move here, the power of this piece lies in its calmness. In the slowly changing contrasts. In the timbres of the instruments that have time and leisure to unfold. Again, the ASR Emitter II Exclusive is in its element: the track feels more intense, pure, more engrossing than with my amp combo. I didn’t really expect that I would ever write such a sentence, as my station wagon is losing out in one of its own domains of all things. Sure, there are comparatively subtle differences, and my Wilson Audio SabrinaX also quite revealing speakers. But it is precisely such subtleties that are important in the high-end sector.

A trade off

Speaking of drum brushes and subtle: I notice something. Doesn’t it normally sound a bit brighter? That’s the way it is – whatever is jacket like pants on this track, it sounds authentic either way. Tracks like “The First Fire” by If Trees could talk (Album: First Fire), which are more about metallic cymbal and hi-hat shine and dirtier overtones from guitars, I then notice that it is even more shimmering and airy at the top. Or to put it more precisely: My combinations of Funk and Norma, and especially Bryston, envelop individual instruments with even more subtle high-frequency components. The fact that they automatically offer more fog or less background black is the flip side of the same coin. A trade-off that makes it difficult to say whether my suits are more transparent or whether the ASR Emitter II Exclusive simply produces less harmonic distortion . At this high level, at which the amps play, it is more a matter of personal taste than a blanket “right” or “wrong”.

ASR Emitter II Exclusive - Kühlkörper im Detail

My ears are drawn more to ASR for quieter, sparsely instrumented music, and more to my Funk/Bryston combo for pieces that are arranged denser, more driving and sparking. At least in team play with the Wilson, who are more reserved than research in the treble. By the way: Friedrich Schäfer writes about himself that he “loves soft pop and jazz” – that actually fits my statement quite well.

On second hearing…

It is logical that his penchant for background black also characterizes the ASR Emitter II Exclusive elsewhere. At first glance, it doesn’t even feel particularly analytical, also because of its treble characteristics. But as soon as you listen more intensively, you are almost surprised at how well the ASR resolves. Especially since the high-frequency range, to prevent misunderstandings, is not a paragon of airiness, but is otherwise clearly defined and accurate. To put it bluntly, the Emitter II Exclusive does exactly the opposite of an AVM Ovation A 6.2 Master Edition .

ASR Emitter II Exclusive - Logo auf der Platine

I’m pretty spoiled when it comes to transparency with my Funk/Bryston combo. And yet over the weeks I experience it repeatedly that with the ASR in complex electronic music or multi-layered guitar textures certain facets or influences of effect devices shine through that seem new to me. Subtly pronounced, but still so noticeable that I involuntarily notice it on well-known tracks. Especially in the middle range , which is also presented in an exemplary manner in terms of tonality. Background blackness, resolution and balanced tonality: the ASR Emitter II Exclusive “can” do mid-range reproduction so well that even the most discerning audiophile will be over the moon. In any case, if realism is given preference over romance.

How about the stage? Well, it can almost be deduced from what has been said so far. The image detaches itself perfectly from the speakers, but is not so airy and offensive that the word “immersive” would escape my lips. At least that’s what it feels like. If you listen carefully, the instruments don’t appear to be smaller than in my Funk/Bryston trio. Either way: The aces up the sleeve of the ASR Emitter II Exclusive are once again background blackness and timbre purity – and consequently the outstanding contrasting/differentiation of instruments that seems to come naturally without any superficial analysis. If the ASR Emitter II Exclusive were a club operator,

ASR Emitter II Exclusive - gelötete Anschlüsse

Lets go on we can do it better …

I wouldn’t describe the above description as a worst-case scenario, but I still admit that I may not have gotten everything out of the ASR Emitter II Exclusive. I didn’t install the spikes that came with it, they won’t be for everyone visually – and I generally don’t put test devices on “special feet”, if only for the sake of comparability. In addition, the possibility of selecting a “direct input” bypassing intermediate relays is a nice option – but with a view to daily listening practice (only one source device possible, switch-on cracker) also quite special.

Before you start writing critical letters to the editor: The Dames wasn’t that lazy to experiment. I usually use XLR connections as a matter of habit, but I also tested RCAs with the ASR Emitter II Exclusive (straight wire Virtuoso served as both XLR and RCA binders). Namely the RCA input number 4, which ASR recommends as the “main input”. In terms of transparency and definition, this is the slightly better choice for my ears compared to XLR. All tracks relevant to the sound report passed door 4 accordingly.

ASR Emitter II Exclusive - Eingangswahlschalter

And of course I had to hit the mouse piano keys: I was interested in what happens when I turn back the high-frequency compensation a little and set all the switches to “off”. And listen: In the high-frequency range, things are actually a bit researcher. Which in the context of the above audio description should go in the right direction? Theoretically yes, practically no: The ASR Emitter II Exclusive may not be the most airy, but it plays extremely well ex works. You can tell that the amp was tuned with sensitivity to the way it sounds by default. The relevant listening rounds took place in the factory setting, i.e. just set switch 1 to “On”.

ASR Emitter II Exclusive - Drehregler und LEDs auf der Front


First of all – and I’m happy to commit myself: In terms of workmanship, concept, design and reliability, which this magnificent example of German mechanical engineering radiates, the ASR Emitter II Exclusive is the most impressive chunk of amplifier construction that has been allowed to spread out in my rack so far . The amp is the exact opposite of off-the-shelf goods and exudes from every pore that a clever, passionate and independent developer has given a lot of deep thought to it over a long period of time. Even a layman will not only pay respect to the unusual case, but also to the quality of the interfaces and the electrical innards when lifting the lid. I find the operating displays shining through the semi-transparent front extremely cool,Advanced listeners enjoy the many special curls that are possible: Do you want certain interface qualities or configurations, color variants, setting options, a headphone output or would you like to try it without a battery power supply first? No problem. And I am sure that you will receive patient and friendly advice on the phone.In terms of sound, the ASR Emitter II Exclusive with battery power supply delivers what you simply expect from such a bolide: In terms of coarse dynamics, control and level stability, it is in no way inferior to large, dedicated power amplifiers.The ASR goes its own way to the other – albeit rather subliminally pronounced: In terms of bass and treble, it seems neither noticeably massive nor overly ethereal, which some will interpret as special maturity, but in any case radiates something like a certain restraint. (By the way, the Emitter II is also available in a “silver version”, in which, among other things, internal wiring made of solid silver wires is intended to ensure an even more sparkling high tone. According to ASR, the tested “copper version” produced a somewhat “rounder” in direct comparison Sound”.)In terms of sound purity, “black background” and thus automatic tone colors, the ASR Emitter II Exclusive marks a benchmark against which even the most expensive amplifiers have to be measured. Especially with quiet, sparsely instrumented music, something very sensual emanates from this amp. For me it is actually something of a new listening experience.The ASR Emitter II Exclusive with battery power supply is characterized by…

  • an exemplary contrasting rendition of instruments/voices that stands out against a strikingly pure background. Outstanding!
  • high long-term suitability. The amplifier plays extremely coherently, due to its tonal tuning “above everything” belongs more with a slight penchant for understatement than bravado.
  • Admittedly not particularly ethereal-airy or sparkling, but very contour-accurate highs. Also thanks to the generally strikingly accurate contrasting, the ASR works out even the most subtle sound events cleanly.
  • a mid-range that has everything that the most demanding lover of realistic sound reproduction could wish for: tonal neutrality, extremely high transparency, strikingly artifact-free purity.
  • a fast, contoured, by no means slim, but not superficially pushing bass range. More integratively tuned than suitable for pressure refueling.
  • high power reserves and level stability. The ASR should have a firm grip on any type of speaker.
  • a spatiality that is also characterized by clean contrasts and therefore clear localization and differentiation. The ASR certainly masters an impressive wall of sounds when required, but in case of doubt it retains its composure better than some amps that are even more shimmering and airy and appealing to the listener more offensively.
  • outstanding workmanship, extremely valuable and designed for a long service life. Very independent, loving design solutions. Many unusual features and optional equipment options. A manufactured product straight out of a picture book.


  • Model: ASR Emitter II Exclusive (copper version) with battery power pack
  • Concept: integrated amplifier, adjustable output stage
  • Price: from 17,500 euros, without battery power pack 14,500 euros
  • High level inputs: 5 x high level (4 x cinch, 1 x XLR, various combinations and qualities possible), 1 x direct input (cinch)
  • RMS power: 2 x 280 watts into 8 ohms, 2 x 500 watts into 4 ohms, 2 x 900 watts into 2 ohms
  • Dimensions and weight (amplifier): 57 x 47 x 23 cm, 47 kg
  • Dimensions and weight (power packs): each 46 x 32 (42) x 16 cm), 32 kg
  • Dimensions and weight (battery power pack): 46 x 32 x 16 cm, 26 kg
  • Miscellaneous: Stable under load up to < 2 ohms, extreme variety of optional features and “extras”, e.g. headphone output: 250 euros, white/blue display or additional inputs/outputs for a surcharge, etc.
  • Warranty: 2 years (3 years with registration)