December 2014


World Premiere!
Aaron Let's Rock! Stereo Integrated Amplifier
Skullish style and sensational substance sounds off.
Review By Wojciech Pacuła

 "Differentiate or die" – the popular business catchphrase is as important today as it was a hundred years ago. While it is most relevant in the world of mass-production products, it seems to be entirely legitimate within our world of perfectionist audio. Aaron's Let's Rock! integrated amplifier as reviewed here, is surely a standout product visually. Within our home turf here in Europe, we usually care about the technical side of the product. Aaron's Let's Rock! is surely within that category. Naturally the company's literature is full of descriptions of special design concepts and solutions, technologies, materials, ideas and philosophy. That is perfectly fine, as this is what our hobby is all about. When it comes to visual design, audiophiles turn out to be generally by very traditional consumers. The model that was developed in the 1970's, where audio products look like lab or recording studio equipment, with low, deep and wide enclosures, and the front panel being the only thing that matters, has survived almost unchanged to this day. As you can see with this review of the Aaron Let's Rock! integrated amplifier, the company chose a highly handcrafted, artistic styling of skulls that would make any enthusiast of such musical genres as rock, metal, alternative, punk, etc very proud.

Perhaps, even more so, Aaron's company owner Thomas Höhne has become part of this new generation that demands both substance and style. In 1986 he founded High-End Consumer Electronics Distribution Company m.b.H. with his wife, Marita Höhne, to "faithfully reproduce music" as we read on various high-end audio websites. The company's full name was too long for a brand name, which is why Mr. and Mrs. Höhne chose its shorter version to emphasize the reference status of their amplifiers. They also wanted to focus their attention on these products to ensure high quality performance. It did not happen all at once; however, as they were selling their first amplifier from 1986, the A300.M monoblocks under the brand name Neumann Audio Technik. Thanks to the success of this project, the company's product lineup was soon divided into two parts: a top high-end line called Sovereign and "only" high-end Aaron. Both of these replaced Neumann Audio Technik in 1989.

I stared this review of the Aaron Let's Rock integrated amplifier by talking about the provenance of audio amplifiers' visual design. Mr. and Mrs. Höhne products did generally look like they were taken straight from a measurement laboratory or recording studio. This was followed by their design from this German company, The Sovereign. This product was two 1.5m towers and were so popular there was a six-month customer waiting time and 129,990 EUR price tag. The Sovereign earned the title of "the greatest amp in the world" in 1995 and were included in the Guinness Book of Records. As you can see by the photos within this review of the Aaron Let's Rock, the styling motif of skulls eschews from the classic look of most audio components, and I take it to include two versions: the vacuum tube design from the 1940s and 1950s and solid-state design from the 1970s and 1980s, generally works well enough for the audiophiles to fully accept it en masse.

Perhaps it is because most music lovers are extremely conservative, and yet also extremely individualistic at the same time. Sometimes they are reflected in a longing for something "different". Both Mr. and Mrs. Höhne apparently gave their best, because the Aaron Let's Rock integrated amplifier has a very telling name. Let's Rock! sports the kind of finish that would be perfectly at home within a "mancave" of any self-respecting rocker. You need not be all inked up, yet perhaps you're dressed in leathers and sleeping within them by your motorcycle. In order not to be too fulsome with changes, the amplifier has a classic shape overall. Let's Rock!'s front panel is, however, a relief with skulls, stars and fleurs-de-lis. To leave the customer with little doubt about what Aaron intends for the overall styling, the top panel features a huge skull bolted directly onto it, which looks like it has just been nicked from some historic cemetery.

A Few Simple Words From Owner / Designer Thomas Höhne
The technology implemented in the Let's Rock!, which was appraised by many international professional audio publications, is based on the AARON No.1a. Our development goal was to surpass the superior sound qualities of our "classic" design with the new Aaron Let's Rock!". We are proud to say that we have been successful in achieving this goal. We developed a completely new preamplifier section for the new Aaron. Its fully discrete circuit includes high quality, carefully selected and matched components to guarantee a variety of tonal detail and the best possible dynamics, even if the music is played back really, really loud. The Let's Rock! has a complex modular design. Comprised of two mono power amplifiers, a separate motherboard and control circuit, it will appeal both to audio technology enthusiasts and rock music fans.

Design
Apart from their decorative role, the very heavy, solid faceplate and a large aluminum component on the top panel serve an important purpose: they stiffen the chassis and dampen mechanical vibration. The customer can choose the surface and color finish of the cast components. If we were to abstract away the basic premise of amplifier itself, we would find it equally interesting as its outer shell. What we have here is an integrated amplifier with microprocessor control as the front panel features two conical knobs that also work as push buttons. They are used as an input selector and volume control respectively. Pressing one of them puts the amplifier in and out of standby mode, whilst the other one brings up the settings menu. The latter allows the user to adjust the input sensitivity, channel balance, as well as run the processing output for use in home cinema systems.

The amplifier is equipped with an absolutely classic, though extensive, set of inputs and outputs. It accepts a line level signal, which can be fed to six RCA input connectors on the back panel, plus it has a preamplifier output and tape loop as well as external processor input and output. Speaker binding posts are a very high quality gold-plated affair. There is also an IEC inlet with fuse. There is no audio "jewelry" to speak about per se as the unit itself is solid, though provides absolutely essential connectors. This pragmatic approach is also manifests itself within the manufacturer's choice of isolation feet, which are plastic bottle corks. Internally, the amplifier has a modular design. Mounted near the rear panel is a large circuit board with a power supply and two preamplifier daughterboards, one per channel, plugged in vertically to the motherboard. The preamplifier circuit is based on matched pairs of bipolar transistors. Volume control is carried out in a 64-step integrated ladder with laser-cut resistors (DS1808-050). The input selection is performed via relays. The same type of relays connect or disconnect the preamplifier and power amplifier sections.

The signal is fed to the power amplifiers via shielded cables. The power amplifier circuits are mounted on two PCBs, separately for each channel of course. They, too, employ a fully solid-state design. The output stage operates in a push-pull class AB and includes carefully matched pairs of transistors, one per channel. These are TO-3 type package, which are rarely ever seen today. Thomas Höhne decided to remove their markings. It just so happens that I have recently reviewed the Passion Amp 650 power amplifier from the French manufacturer YBA, in which I found very similar looking active components. They were ON Semiconductor MJ15024G + MJ15025G bipolar transistors. The TO-3 transistors used in the Aaron are mounted to a small aluminum channel bar to aid with proper heat dissipation, together with driver transistors. Those channel bars are bolted, in turn, to an average size heat sink. The Aaron Let's Rock! Integrated amplifier never operated too hot during the review process, so it seems that the bias current is set to a low value and the amplifier operates within Class AB all the time.

The power supply uses two transformers. A large 500W toroidal transformer supplies electricity to the power amplifier (and perhaps the preamplifier section too) and a smaller regular type transformer that powers the control circuit and (most likely) relays. The preamplifier and control circuit power supplies include voltage regulators and the power amplifier supply voltage is rectified and filtered in a capacitor bank that comprises six 10,000 uF capacitors. One of them sports Thomas's hologram sticker and markings. Could it perhaps mean that there have been attempts to make illegal clones of Aaron amplifiers? The amplifier circuit employs good quality and visually attractive passive and active components. All internal cabling is sensibly distributed. The only thing that I was not too sure about is running the power supply and speaker cables in parallel, but apparently that does not alter the amplifier's measurable parameters. Aaron's Let's Rock! remote control is large and made with aluminum. The user manual is well written and nicely printed. Instead of the usual metal "clip," the manual pages are held together with a leather strap and a small skull pendant tied to it. A very solid, hand assembled, quality high-end piece of audio equipment deserves such treatment.

Sound
I distinctly remember the night on September 2^nd, 2001, when together with 33 thousands other Depeche Mode fans I was getting wet in the rain at the Służewiec horse racing track in Warsaw, Poland. We were screaming our heads off and singing along with the band. We were also shouting at the privileged ones who were standing on their chairs in the VIP sector and blocking our view with their umbrellas. Our vociferous "get your f... umbrella down", "get off your chairs" and other requests were filling the air. Not only were they quite effective but the rain stopped after a time, too. The latter went unnoticed, though, to be honest with you. It was the second visit of the band in Poland after 16 years of absence. When they first came in 1985, I did not even know about their existence. The 2001 concert was being recorded by the Polish commercial television network TVN, a co-organizer, together with Program Trzeci Polskiego Radia (Polish Radio Three), and was to be broadcast later. Alas, due to technical problems caused by the rain and the poor quality of recordings, it never came to be. The concert has probably been shelved and awaits better times. Recollections from concerts always come to my mind when someone declares that the sound reproduced at home should be "as close as possible to the one we get during the live concert". We understand that intuitively. Ultimately it is a proper demand and is in line with the purist approach. If we, however, stop to think about it for a while it turns out to be nothing but a kind of a dream of a reproduced sound to be identical to its source.

Leaving the philosophical aspects of such a claim aside, the Platonic cave, the postmodern indeterminacy (or situationality, the dependence of our perception of a given object on many factors), it is quite easy to point out the utopian character of that approach. Suffice it to say about the variety of microphone techniques employed during audio recordings, each of them with its own pros and cons and none being absolutely perfect. One could also call to mind the specific recording and monitoring methods when the "stereo" sound (in a Greek sense of the word where it means "solid" or integral, indivisible) is reproduced by a finite (i.e. 2, 5, 7, 10 and more) number of speakers.  Or you can go to any given concert and then try to repeat that experience at home. I believe we have all experienced that many a time and the verdict is one: it is impossible.

I started the auditions with Dead of Night off Depeche Mode's Ultra, the track which was the first one to follow the electronic versions of Easy Tiger and Dream On 13 years ago in Warsaw. The bass that rolled over us then, its sheer weight and power, is only possible to experience in the open air, using massive stage speaker systems capable of outputting tens (if not hundreds) of thousands of Watts. The same track listened to on the Aaron amplifier and my Harbeth M40.1 speakers, as well as the Trenner & Friedl Isis speakers, and played back from the best available spec CD2 album release did not even come close to what I remembered from the concert. Since the memory cannot be fully trusted 100% of the time, I also auditioned several albums heard during the live gigs including King Crimson and The Crimson ProjeKCt (March 20^th, 2014, Klub Studio, Krakow), Peter Gabriel from his album So (May 12^th, 2014, Atlas Arena, Lodz) and Daniel Miller (May 23^rd, 2014, Bielskie Centrum Kultury, BielskoBiala). If I wanted to repeat the live gig experience at home, even sitting in front of my speakers with their powerful woofers (Harbeth: 300 mm, Trenner & Friedl: 380 mm), I would have to say that the music played back at home had nothing to do with the live gig, that is – by implication – with the reference or model event.

Fortunately, I have no such illusions. Actually, I never had. I understand music playback at home as a completely new reality, in some way connected with the act of playing music in the real world, but rather being a different kind of art. Hence, I was very impressed with the sound of these albums when using the Aaron Let's Rock!. Thomas Höhne designed an amplifier that plays the rock music in the way the rockers rarely get the opportunity to listen to. It is refined enough for other types of music and did justice to the recordings. The sound of this component is extremely well ordered. This characteristic is not necessarily associated with a rock 'n' roll life, is it? Perhaps it is less so with this kind of music. However, music playback is an act which may not always mirror clichés from other areas of life. The Aaron Let's Rock! is a great case in point that all you need for a proper reproduction of a given type of music is simply a consistent, dynamic and refined amplifier.

The refinement of the Aaron Let's Rock! is primarily manifested in its well-ordered sound. The tonality is even and the tones are rich in harmonics, liquid and dense. Guided by the amplifier's name, I spent a large part of the auditions on listening to rock music, in all its varieties of course. I took the most pleasure in Platinum SHM-CD releases. If anyone says that the way the CD is made does not affect its sound quality, let them just pause for a moment and listen to this newest "patent" from Universal. Cream, Queen, Derek & The Dominos, Dire Straits, The Rolling Stones, The Who, Asia and even Mike Oldfield – all these CDs sounded very interesting and if I were a megalomaniac I would say "analog." Their sound was dense and well differentiated.

What was particularly captivating in this presentation was a great combination of great order, outstanding rhythmic ability, excellent frequency extension – both from the top and the bottom – and its forgiving character. This is not the kind of amplifier that brings out music production flaws and examines them. Nor does it ‘wag its finger' at them, reprimanding the sound engineers and music labels for their errors. I think it does it by ever so slightly reducing the attack transients. I have no doubt that a number of fans of harder styles of music will point to the "softness" of such sound. And they will be right. If they believe it to be a downside, the Aaron amplifier may not be to their liking. Despite its great differentiation of instruments' bodies, their directionality and tonal quality, the Let's Rock! will soften the impact that some rock musicians are fighting for. Having experience with various types of amplifiers, I choose this way of music playback without any doubt or hesitation. It is a good sound, regardless of what you listen to – be that rock, classical, jazz, ethno, folk, blues or any other type of music. If you can come to terms with the lack of garishness, artificial selectivity and hyper-detail, the German amplifier will prove to be exactly the kind of amplifier the rockers need. It will make all albums sound enveloping, multifaceted and deep. The better the recording, the more enjoyment you will receive from its sound. Yet with lower quality productions, like the 2003 SACD version of Gabriel's So, like Layla from Derek & The Dominos or like black metal albums, which are usually only listenable on vinyl, you can still enjoy the music.

The amplifier has a very low bass, which is at the same time very well-differentiated and defined. It will never get hardened, though. The upper treble is rounded, but not recessed. The Depeche Mode album Ultra has a rather hard sonic signature, especially at the top end. The Aaron played it back dense and full, without withdrawing the cymbals. Nor did it let them break away from the rest of the presentation, which is widespread. And the sound was full-bodied, which I earlier heard on the 1971 live album from Guru Guru, released as a nice box set by the United States label Cleopatra Records.

Conclusion
The name Let's Rock! pretty much suggests the company's target group of customers. In the study of literature, the reader envisaged by the author is called a "virtual reader". I am not saying I know this for sure, but have a feeling that this is the way Thomas winks at us. The amplifier looks, the whole act, is impressive. It is impossible to just pass by, and the amplifier will be a "stylistically loaded part" of room design, so to speak. Rock music sounds great and you can finally listen to it, regardless of the provenance of recordings. They are all well differentiated and in this case, differentiation consists in demonstrating tonal and dynamic changes, but without unpleasant consequences. Subtle details and selectivity play subservient role here and it is hard to speak about any particular insight into instruments' textures or an abundance of reverb behind the instruments. The most important aspect is the foreground, not just straight in front of us, but also very widely into the sides and deep into the soundscape. This is something most listeners will discover for the first time on rock music albums when sing Aaron's Let's Rock! Solid-state integrated amplifier. I find, at times, many of these rock albums tend to sound almost like mono or flat recordings.

But what about the wink I have mentioned earlier? It lies in the fact that the Let's Rock! fantastically played back the albums that come from a completely different planet, like Billie Holiday recordings that had been originally released on 10" vinyl LP in 1952 and 1954, or Relaxin' With The Miles Davis Quintet on Platinum SHM-CD and others. The depth, density, beautiful timbres... everything that turned the hard rock tracks into the moment of "contact" with the musician were also brought forther musically akin to time captured within a capsule. Not in the sense of slavish "imitation," because verismo is nearly a dead end in audio circles. And in terms of creative re-creation of the musical event, giving it meaning and probability, we "buy" into it without hesitation while being fully aware that we are listening to a mechanical reproduction... perhaps a tiny bit distant from the actual live event.

Review Methodology And Tips
The amplifier was auditioned in my main reference system. It was compared against my two-piece amplifier that includes the Ayon Audio Spheris III preamplifier and the Soulution 710 power amplifier. During the time of the audition, I also listened to the Mark Levinson No.52 preamplifier. The front end was the Ancient Audio Lektor Air V-edition CD player with a tube-based analog section. The speakers were the Harbeth M40.1 and the mighty Isis from Trenner & Friedl that sports a 15" woofer. The signal was fed via the Triple C-FM, the newest cables from the Japanese company Acoustic Revive. The power cord used was the GPX-R V2 from another Japanese company, Oyaide. The entire system was seated on the Finite Elemente Pagode Edition rack. However, as the amplifier's feet are simple plastic "corks," underneath I additionally used the Ceramic Disc Classic footers from the Polish company Audio Franc Accessories. The amplifier worked perfectly fine during the whole review time and I did not have any single problem with it.

Looking for a matching pair of speakers, it is worth considering speakers from Harbeth or the Classic line from Spendor. That will be a safe choice and you get in return a beautiful tonality and low, meaty bass. I think, however, there are speakers that seem to be made just for the Let's Rock! – the JBL Studio Monitor 4429 for example. Display screen and front panel color finish? Check! Rock connotations? Check! Matching sound? Check! Putting together such a system you will receive an added value – a sensible, well thought-out audio system with classic pedigree and with a sparkle.

Albums Auditioned During The Review
• Billie Holiday, Billie Holiday, Clef/UMG Recordings UCCV-9470, "David Stone Martin 10-inch Collector's Selection", CD (1954/2013).

• Brainticket, The Vintage Anthology 1971-1980, Cleopatra Records | Purple Pyramid Records 57594829, 4 x CD (2011).

• Chopin, Waltzes, DinuLipatti (piano), EMI Records CDC 7 47390 2, CD (1950/1986).

• Cream, Disraeli Gears, Polydor/Universal Music LLC UICY-40023, Platinum SHM-CD (1967/2013).

• Deep Purple, The Audio Fidelity Collection, Warner Bros./Audio Fidelity AFZB 019, "Limited Edition  No. 0878", 4 x gold-CD (1970, 1971, 1972, 1973/2013).

• Depeche Mode, Ultra, Mute/Sony Music Labels, Blu-spec CD2, (2007/2014).

• Derek & The Dominos, Layla, Polydor/Universal Music LLC UICY-40004, Platinum SHM-CD (1970/2013).

• Diary of Dreams, Panik Manifesto, Accession Records EFA 23452-2, CD (2002).

• Dire Straits, Dire Straits, Vertigo/Universal Music LLC (Japan) UICY-40008, Platinum SHM-CD (1978/2013).

• Dire Straits, Love Over Gold, Vertigo/Universal Music LLC (Japan) UICY-40029, Platinum SHM-CD (1982/2013).

• Guru Guru, Live in Germany ‘71, Cleopatra Records CLP 6844-2, CD (2011).

• Mike Oldfield, Tubular Bells, Mercury Records/Universal Music LLC (Japan) UICY-40016, Platinum SHM-CD (1973/2013).

• Miles Davis Quintet, Relaxin' With The Miles Davis Quintet, Prestige/Universal Music LLC (Japan) UCCO-40005, Platinum SHM-CD, (1958/2013).

• Mobley/Cohn/Coltrane/Sims, Tenor Conclave, Prestige/Analogue Productions CPRJ 7074 SA, SACD/CD (1957/2014).

• Queen, A Night At The Opera, Island/Universal Music LLC (Japan) UICY-40006, Platinum SHM-CD (1975/2013).

• The Rolling Stones, Exile on Main St., Atlantic/Universal Music Company (Japan) UICY-40001, Platinum SHM-CD (1972/2013).

Specifications
Type: Solid-state stereo integrated amplifier
Output Power (Continuous): 100 Watts per channel @ 8 Ohms (180 Wpc @ 4 Ohms)
Volume Control: 64-step Log digital controlled ladder switch 
THD: 0.1% 
Maximum Pulsed Current: 22 Amperes (100ms burst) 
Minimum Load: 1 Ohm
Distortion THD: 0.0115%
Distortion TIM: 0.012%
Hum And Noise Level: -98dB @ maximum output level 
Bandwidth: DC to 130 kHz (-3dB 1W/8 Ohms) 
Input Impedance: 47 kOhm
Damping Factor: 600 
Slew Rate 21V/μS
Power Supply: 500VA toroidal transformer and six 10,000uf capacitors

Features
Each input channel programmable - input gain (-16dB) 
Each output channel programmable output gain (-16dB) 
Programmable processor switch for stereo input/output
Infrared remote control 
Protection: Internal fuse on power rail only (no current limiting) 
Power amplifier mute on switch off

Inputs: Six stereo line input RCA gold plated 
Outputs: Two stereo pre out and processor out via gold plated RCA jacks 
Controls: Two rotary encoder with push button 
Loudspeaker Outputs: Two sets of gold plated binding posts
Dimensions: 17.32" x 4.25" x 14.75" (WxHxD in mm) 
Shipping Weight: 34 lbs.
Available Styles: Silver machine design or catacomb style
Price: €5000 or approximately $6200 USD

Company Information
High End GmbH
Voice: +49 5068 2858
E-Mail: info@hifi.net
Website: www.Aaron-Amplifiers.com