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A dream came true – Abyss AB-1266 driven by AudioValve RKV III

  1. Volker
    Dear Head-Fi members,

    today I want to share my experience with the Abyss AB-1266 being driven by the AudioValve RKV 3 tube headphone amp. This article is about the story how both finally became my components for the lonely island - after a longer research and trying out and comparing different components. One fundament of finding these components were the comments of many enthusiasts in Head-Fi and other platforms. It would be a pleasure for me if my post would be valuable to some headphone maniacs planning the next buying decision.

    In the following I compare the Abyss und AudioValve to some competitors (especially STAX SR 007 MK 1 and MK 2, SR 009, Audeze LCD 2 and LCD 4, Headamp Blue Hawaii, Cavalli Audio Liquid Gold, Octave V16, Violectric V 200, STAX SRM-007T).

    Before starting I want to explicitly state that my judgements reflect what I hear and what I like based on my preferences, they are subjective. Reading some very different stories what people hear with different headphones let me wonder whether the shape of the head and the ears is broadening the range of different individual perception with headphones in comparing to loudspeakers. In addition, based on my experience the interaction between headphone amp and headphone is more critical than you would expect. My ability to compare to other products is limited since I have heard only a few components. I did not hear all these great products being available to us headphone community since several years. I plan to try HiFiMan headphones in the future, reading all the articles give me the impression that I really need to do that to have a broader view.

    Behind the purchase of expensive high end gear there is normally a long individual high end history. Some insights into my individual development path …

    STAX SR 007 MK2 / Headamp Blue Hawaii

    I am a long-standing customer of STAX. I love these headphones with their silky smooth presentation and resolution, especially when hearing classical music. Looking back to years of wonderful listening experience and stable second-hand values I regard my investments in STAX products to the best one I have made. Listening to STAX for years built the base for my strong focus to headphone listening, which today gives me by far more musical joy than listening to loudspeakers. Because I really like it and I simply spend more time listening to headphones when I have the slot for music later in the evening. I ended up with a STAX SR-007 MK2 together with the tube amp Headamp Blue Hawaii.

    The tube amp SRM 007t was for a long time my favorite of all STAX headphone amps primarily because of the sonic qualities in reproducing classical music, which I rate as being superior (fluent and smooth) to the STAX transistor models. I love classical music. But also pop and jazz, so at the end I like it all! I upgraded three years ago to Headamp Blue Hawaii. It is an improvement in comparison to SRM 007t: more dynamics, deeper and tighter bass, more neutral. The differences are significant, but the sonic experience with Blue Hawaii is not worlds apart. In total the Headamp Blue Hawaii is a wonderful component, I can understand why many see it as the best way to drive STAX headphones. Most listeners seem to prefer the SR-009, some tend to the older initial SR-007 MK 1 instead of the current MK II version. If this preference distribution is right, I belong to the minority - preferring the current SR-007 MKII. This fact is an indicator that the other preferences I hear and mention below might also not be shared by the majority. My ears rated the SR-009 as to bright, a little bit too lean and somewhat mechanical sounding, not so natural and lush like the SR-007 MK II. Many criticize the SR-007 MK II in having too much energy and not enough precision in the low frequency range. Yes, I also hear this when driven by STAX 007t and as well when driven by Headamp Blue Hawaii. But it did not reduce my satisfaction listening to STAX – at least until the Abyss entered the scene, will come back to that later. I position the initial version of the SR-007 MK 1 between the full bodied and lush SR-007 MK2 and the very analytic SR-009 in the sonic range. The reason why some look for the older MK1 version, praising the MK1 as the “sweet spot”. Good for me, I got a good price when selling the SR-007 MK1 after I have owned and used them for a long time. Did not hear the new version SR-009s, but Head-Fi and other sources says that the sonic footprint of the new version is similar to that of the SR-009.

    During the last years my focus towards headphones increased because of two positive drivers: my young daughter (together with my wife unfortunately not sharing my loudspeaker passion) and all these great headphones and headphone amps entering the market.

    Audeze LCD-2

    Reading all these enthusiastic reviews I was afraid I could miss something hearing only to my good old STAX. The reason I tried an Audeze LCD-2 years ago. A very good headphone with great look and feel. But at the end I had to recognize that after the attractiveness of being new and exciting was gone I did again prefer the STAX for most of my listening – regardless of the type of music. Only in the case of heavy rock or pop with extensive dynamics and low frequency energy I used as an exception the Audeze. With the LCD-2 I did not hear the high frequency resolution of the STAX, that is so important to me, I missed the delicate characteristics taking care of every musical detail, which makes the STAX so special.

    Abyss AB-1266

    Four years ago during vacation I spend a lot of time reading US high end magazines (stereophile being my favorite, no other magazine shows the depth in both dimensions of listening and measurements). I detected a strange and to me not very attractive looking new high end model called Abyss AB-1266. I read some enthusiastic reviews about it and therefore decided to buy it without having seen or heard it - that time no dealer had it available here in Germany. I paired it with AudioValve RKV III. What a great groundbreaking experience! It confirmed an old rule: after 7 seconds you know whether you like it or don’t, whether something new and very special is happening. As well as the STAX the Abyss offers me a similar level of smoothness and liquid sonics. But the Abyss AB-1266 combines it with greater dynamics, incredible bass performance and a tangible and grounded sound. It is by far more dynamic and transparent in the lower frequencies – without the disadvantage that the Abyss does produces too much energy in the lower frequency range. That difference reveals very clearly the weakest point of the STAX (007 MK II). The sound with Abyss is also very lush – I love this. I hear dynamics and precision I don’t hear with the STAX, my ears rate the Abyss of being more neutral and clear. I did not hear a slight edginess some report about the AB-1266 – may be one part of the answer are different tastes, the second part could be the headphone amp (also heard a slight glare for example when driven by Cavalli Audio Liquid Gold). The Abyss is so good that I can’t stop listening to my vinyl, CD's and FLAC-files. No other headphone is minimizing my feeling that the music is playing in my head so much as the AB-1266. Instead of a feeling that the music is focused to a point in the middle of my head the AB-1266 opens a very broad musical room. I hear music reproduction like never before. For me this headphone represents a huge milestone in headphone development. The Abyss beats the STAX even in the home turf of the STAX, classical music. But the distance is not so huge as with the other music genres. The reason that I prefer the Abyss also with classical orchestral music can be clearly located in the frequency range – orchestral music contains a lot of low frequency energy, being produced by a lot of instruments. The Abyss is in a very positive analytical way elaborating the multilayer structure of the lowest and low mid octaves. Hearing with the STAX I don’t hear that contours, details of this frequency range wear off, dynamic is missing.

    I own and describe the initial version of the AB-1266. I plan to check out some day the newest Phi version. Often companies that have a long track record in a certain technical domain have collected all the knowledge and experience that is needed to create an outstanding product in that specific domain. Another option is to buy in the expertise from a specialized company if you don’t have it. Sometimes it is different. Rarely some brave innovators start from scratch to overcome existing limits. Joe Skubinski and his team tried it and made it. An impressive example of that business rule.

    Jena Labs headphone cable

    In my configuration I needed a longer headphone cable for the Abyss. I purchased a cable called „Headphone Harness“ from small US based niche company Jena Labs (distributed in Europe by Lokesh from emotionalaudio in Netherlands). A good decision. Look and feel is very good. Sounds very good, but I did not spend too much effort to compare sonically to the JPS cable, I did not hear significant differences. The cables of both channels are stranded and the cable is very flexible, so for sure I can say that I prefer the handling in comparison to the original Abyss / JPS cable. In my hum sensible environment the Jena Labs cable is also less sensible to hum when touching it with my hands having the feet on the ground (as I normally have when listening).

    Audeze LCD-4

    After reading very good reviews about the Audeze LCD-4 one year ago I had the chance to directly compare it to my Abyss AB-1266, both driven by my AudioValve RKV 3.

    The Audeze LCD-4 sounds different. Very deep bass, very full bodied and warm. Far more resolution than the LCD-2. For me this signature comes with a sound that is a little bit too “heavy” and bass oriented. The AB-1266 benefits in being - for my ears - more agile and in a positive way lighter rsp. more aerial. Positive, since there is no lack of bass energy und dynamics, no impression of not being full bodied, you don’t miss anything, no downside.

    My head rated the Abyss Ab-1266 of being more comfortable to wear than the LCD-4. With the LCD-4 I had always the impression that there is something heavy on my head. I sometimes wondered whether this physical perception of my head influenced what I heard – huge and heavy sonics.

    The rating was at the end clear – the AB-1266 remains the best choice for my taste.

    AudioValve Mark RKV III headphone amp

    Let’s talk about the amplification part. Today there are so many choices, every month new headphone amps announced – good times for headphone audiophiles! But if you want the best and the also the ideal match for your specific headphone (s) the amount of choices can be reduced.

    I only heard a very small portion of the available headphone amp choices the market offers. So I am not able to give general ratings like „best headphone amp in the world“. And to reduce the scope of my comparison even further – I heard the amps only with these headphones: STAX SR-007, STAX SR—007 MK II, STAX SR-009, Audeze LCD-2 / LCD-4 and Abyss AB-1266. Based on my listening sessions I learned that an assessment of a headphone amp could be and sometimes definitely will end differently depending on the headphone you drive.

    I heard the Violectric V200, Fosgate Signature, Bryston BHA-1, Cavalli Audio Liquid Gold, Headamp Blue Hawaii, the headphone amp of my former Accuphase C-2400 preamp and the Audio Valve RKV Mark III.

    My absolute personal favorite is the Audio Valve RKV Mark III. Smooth and very dynamic. This powerhouse is also strong in subtle details. The Abyss is so lively with the Audio Valve. It seems that the Abyss need some freedom to play, maybe you know that kind of passion by a symphony orchestra being directed by a great conductor encouraging them to play without too much control – they will play being inspired. The Audio Valve has that kind of smooth characteristics that I like with STAX – without harshness. It seems to me not being a deviation to neutrality and power. Pop and Rock are sounding great. Incredible bass performance – so tight and deep. And in addition a very delicate reproduction of tone colors and a very three-dimensional sound I never experienced so good with a headphone before.

    In addition to the sonic merits I love the RKV III because I can see inside the amplifier. I can imagine where the music finds the way through the circuit – without being harmed. The glow of the eight tubes is wonderful. I am only using tube amps for amplification (AudioValve, Headamp Blue Hawaii, VAC phono amp, Octave mono amps), primarily based on sonics, but their look is for me a second strong argument. Audio Valve and Abyss are both not looking reduced like purist Bauhaus-style. After some weeks in my home I now think they represent a „good and characterful looking couple“. My daughter is now old enough to make jokes when she sees me with the AB-1266 – can live with that - did not buy the AB-1266 to impress my family or neighbours

    I like the company Audio Valve. Mr. Becker, founder and CEO with an academic technical background in electronic engineering has been long in the business, his company can offer a tradition. He is passionate and has so many experience. He is one of that technical oriented small size company owner that keeps the economy going! He is very responsive to me. I can talk directly to him. You want to talk to a smart sales guy, prefer a polished web presence, demand brochures in brilliant English and other items that distinguish a large professional company with strong brand value? You may be better look elsewhere.

    My report relies on the initial version with the PCL 805 tubes. Regarding Mr. Becker the ECL 85, used from 2016 on, offers a little more output power. Yet I haven’t read anything about sonic differences. The reason to change the tubes was solely the limited availability of the PCL 805. I bought enough PCL 805 from ebay (Valvo) to listen for the next decades, so my tube stock will not be the bottleneck.

    In addition to my sonic experience I want to share my practical experience in day to day operation.

    I use the RKV III now over four years. It worked all the time trouble free without any problem. Important for me is also the fact that you don’t hear any hiss or hum, also no noise during start up or shut down procedure. Take care in the case that you connect the RKV III via Y-adapter to your source. When switched off or for the inputs not being currently selected the source will see a significantly reduced resistance. No panic, there is not a risk of a damage, but you just need to know that the level in case of a parallel connected amplifier is reduced since a significant part of the current prefers the path to the RKV 3 with the lower resistance.

    With the Abyss I use the RKV Mark III 64 Ohm impedancer setting. It sounds smoother in comparison to the 128 Ohm setting. May be listeners looking for dynamics of pop and rock will prefer 128 Ohm. You can use also the OTL mode, this sounds like formula 1, but the sonics are for my taste far too forward and show some glare. Helmut Becker says that the measurements of the impedancer mode are worse in comparison to OTL mode. Some years ago Pierre Paya from casques headphone (France) wrote euphoric about the combination of AB-1266 with RKV 3. He also preferred the impedancer path – but with 128 Ohm setting, which moves the sonic character only a little bit towards the OTL mode.

    In theory every transformer will harm the signal. But my practical experience says something different. I use Martin Logan Prodigy electrostats, which uses transformers to produce the high voltage for the panel. The best sonic results I achieve with tube amps (the best mono amps I selected after a lot of comparisons are the Octave MRE 220). This amp adds another output transformer to the signal path. Transformer number one in the tube amp increases current (decreases voltage), then afterwards transformer number two does the opposite. But what counts at the end is what you hear. You may argue that the superiority I hear with tubes is based on the tube concept, not on the transformer. Yes, but also using transistor amps with a transformer is not in principle a disadvantage. You can achieve astonishing good sonic results with McIntosh amps and their unique Autoformer concept (an adjustable impedance matcher) driving the Logan stator. Better than with many other high rated and even more expensive amps.

    In one sentence: listening via Audio Valve RKV III and Abyss is the best listening experiences I can imagine.

    Cavalli Audio Liquid Gold headphone amp

    I compared my AudioValve with the Cavalli Liquid Gold driving my Abyss. I like the AudioValve by far more. More natural, lush, dynamic, three-dimensional – it sounds fluent. The Cavalli sound more dry, mechanical, lean. Often the advantages and disadvantages of components playing on the same level are distributed in a balanced way. My ears tend to really LOVE the AudioValve: I can’t detect criteria were the Cavalli has a sonic advantage for my ears. And for me it is a huge difference. That was and is still a surprise to me, some rate the Cavalli as a very good choice for the Abyss. Cavalli – now out of business – are in general known for excellent products. The difference is by far more significant than the difference between STAX SRM-007t and Headamp Blue Hawaii.

    Violectric V 200 headphone amp

    The Violectric V 200 is not so dynamic, it sounds also smooth, very controlled, a little be too controlled in comparison to the Audio Valve, with less bass power in comparison to Audio Valve RKV Mark III. Considering the low price I rate the performance as very good. But after I bought the AudioValve hearing with the Violectric is no fun anymore. I sold it.

    Octave V 16 tube headphone amp

    Two years ago Octave Audio released their V16, a single ended headphone amplifier which can be used also as power amplifier for very sensitive speakers. Not cheap with a list price of around 8.000 Euro in Germany. Since Octave components belong to my favorites I had to compare the V 16 to my AudioValve.

    They sound very similar (when configuring the AudioValve to impedancer mode with 64 Ohm). I heard them in direct comparison. I doubt that I would have heard a difference without having had that setting being able to switch and compare within a few seconds.

    The only difference I could detect on a reliable basis concerns the higher frequencies. The AudioValve shows some gloss (you could it describe also as “air” or “magic”) that the Octave did not show. I have to confess that I am not able to determine whether this magic is an indicator of a higher resolution or some sweet-natured distortion. The only thing I can say is that for most time of my listening I ended up saying that it enriched my listening pleasure. Only during some musical pieces with voices I had the impression that the Octave is more natural – these were the moments were the brain said “THIS is right”.

    But again, this small sonic deviation is very subtle. That led to an obvious conclusion for me - I was already proud owner of the AudioValve, the price tag of the Octave is much higher than that of the AudioValve and I had a slight preference for the AudioValve. I kept the AudioValve, I saved money for next best upgrade

    Coming to the end

    Sooner or later It will come, things go on, my brain’s objective experience says there is never a final state, even if you sometimes feel that you reached the optimum. Abyss AB-1266 Phi, HiFiMan Shangri-La, Fostex HP-V8, or some future products I yet don’t know …?

    Currently I feel no need to change anything, I am just enjoying music and I am very happy about my heart’s emotional feeling during listening - that it is musical heaven on earth just as it currently is.

    Kind Regards,
    Ableza, cj3209, cerol and 4 others like this.
  2. Grimbles
    Thanks for sharing buddy.
    Volker likes this.
  3. lambdastorm
    Nice write up! I feel the same way towards 007 and Abyss, and that is the Abyss defeats 007 even on their home turf, classical and orchestral music. The Abyss manages to sound extremely transparent yet not overly analytical on a good setup. Too often with STAX cans they draw your attention away from music and into those delicate micro-details, but Abyss manages to present music as a whole while revealing every tiny detail much like a 'stats can.

    I love mine.
    Volker likes this.
  4. Ableza
    Excellent write up. As an Audio Valve Solaris owner, I can attest to the outstanding performance and sonic clarity of the RKV design. In my opinion it is in a class by itself. Thank you for sharing your impressions!
    Last edited: Aug 10, 2019
    Volker likes this.
  5. chimney189
    Nice write up
    Volker likes this.
  6. cj3209
    Thank you. After reading your great write up, I no longer have a desire to try out an electrostatic set up. My Phi CC's are incredible!

    Volker likes this.

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