Marten Bird Loudspeakers, Marten Duke 2 Loudspeakers, and REL Stadium III subwoofer

E.A.R. 324 phono preamplifier, [2] E.A.R. 890 amplifiers (run as monos), E.A.R. 534 Stereo Amplifier, E.A.R. 912 Professional Preamplifier, E.A.R. 834L Tube Line Stage, E.A.R. HP4 Headphone Amplifier, Grado Battery Headphone Amplifier, and KingRex Headphone Amplifier.

Analog: E.A.R. Disk Master Turntable with two Helius Omega Tonearms. Digital: E.A.R. Acute III CD player, E.A.R. Acute 1 CD Player, ModWright Sony 9100ES SACD/CD/DVD Player with Signature Truth Modifications, Mod/Bybee Filters and Revelation Cryo Silver Umbilical. ModWright Sony 999ES CD/SACD/DVD Player with signature Truth Mod and Tube Power Supply, and Alesis Masterlink 24/96 Recorder/Playback Deck. Cartridges: Koetsu Rosewood Signature Phono Cartridge, London Reference Phono Cartridge, and Grado Statement1 Phono Cartridge. LD: Pioneer DVL 919 CD/LD/DVD Player. Tuners: Magnum Dynalab MD-108 Reference Tuner, Marantz 10B FM Tuner, Day Sequerra Reference FM1 Tuner, McIntosh MR71 FM Tuner, Dynaco AF6 FM Tuner, and Marantz ST17 FM Tuner. Headphones: Stax 7t Electrostatic headphones, Grado RS1 headphones, Grado PS 1000 and PS 500 Headphones, Ultrasone Edition 8 Headphones,and Koss ESP950 Electrostatic Headphones.

Kubala-Sosna Elation Interconnects, Speaker Cables, and Power Cords. Kubala-Sosna Emotion and Expression Interconnects and power cords, Jorma Design Origo Interconnects and Speaker Cables. Harmonic Technology Magic 2 Interconnects, Magic 1and2 Power Cords, Fantasy Power Cords, Kimber D-60 Digital Interconnects, Kimber Select 3038 Silver and Silver/Copper Interconnects, CRL Silver Interconnects and Custom WyWires Interconnects.

Monster Reference 350 Mark II v2 Power Conditioner, World Power Wing Revised Power Conditioner, Tice Power Block, Tice Clock, and Audio Prism Quiet Line IIs. Anniversary Edition Cable Cooker 2.5, Winds Stylus Pressure Gage, Bedini Ultra Clarifier, VPI Record Cleaning Machine 16.5. Audio Magic's Quantum Physics Noise Disrupters, Marigo Mystery Feet, Townshend Seismic Sinks, Furutech Demag, RSC Sound Panels and 16 inch Bass Trap, and Shunyata Cable Lifters.


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Positive Feedback ISSUE 75
september/october 2014



AK240 Digital Audio Player

as reviewed by Robert H. Levi



Much has been written about this Swiss army knife of a DAC from Astell & Kern, but some things have been missed. The AK240 powers up headphones well, better than any other portable player on earth I know of, but it does more than just fulfilling the dream of "have headphones, will travel." I know! I pushed it to the max!

First, I ran it through its paces as a headphone music player. I loaded it with albums from top sources in 16/44.1kHz through 24/192 PCM, and on through DSD, and finally through double DSD! I managed to fill only 70% of its capacity with all those albums. By the way, its battery capacity is very robust, as an entire afternoon of listening used only half of its energy storage.

Cans Used for Audition:  

Audeze LCD-X with Fazor

Grado PS1000e

Grado PS1000

Grado PS500

Grado RS1

Alpha Dogs by MrSpeaker

Ultrasone Edition 8

After playing each headphone for a minimum of one hour with challenging material, I found no headphone which was not well served by the AK240. Frankly, the Audeze LCD-X sounded glorious with the little 8oz AK240, and was difficult to put down! The Grado PS1000e sounded like I was in the recording studio, and the clarity of each high resolution recording was stunning! I had no idea portable headphone listening could be like this. The AK240 is seriously cutting-edge 21st century as a portable headphone player. 

As A Server in a High Resolution System

Now the real fun begins! Could the AK240 be a server in a high-resolution super system? I moved into my main reference system, consisting of Marten Birds with REL Subs, E.A.R. 912 Preamp, two E.A.R. 890 monoblocks, and the E.A.R. Acute 3 CD Player. All is wired with Jorma Origo interconnects and Kubala-Sosna Elation and Emotion Power Cords. 

I set the AK 240 to fixed output, 2.1 volts max, from the single-ended stereo jack, and attached a gold-plated adapter, which was terminated in two single-ended female RCA plugs. I auditioned several sets of interconnects, and found that the AK240 sounded just like the wires I used to hook it up to the preamp! Based on this revelation, I went for the most neutral wires available that would fit the small adapter coming from the AK 240. Please do not laugh or curse: I used the Jorma Prime Interconnects at $9750 per meter. I truly wanted to review only the sound of the AK 240, and not the sound of compromised interconnects. I realize this is an unlikely pairing, but the Primes sound like nothing at all, and in this case, that is very good.

I invited over two audiophiles with superb taste to listen with me and see if the diminutive AK240 would take us to the new world of advanced digital downloading. 

The answer: We were in awe of the performance of the AK240 as a server! We could not find anything to criticize. The DSD performance of Kind of Blue was a knock-out! The DSD performance of Time Out was mind bending! The Double DSD performance of High Definition Tape Transfers’ Ellington Indigos was spellbinding! In fact, even the 16/44.1 downloads sounded smooth and musical, as good as any CDs any of us had ever heard. About the only conclusions we could draw was that the Double DSD recordings were the most realistic and alive. The others were a bit less. None were ordinary or poor. The AK240 is very special indeed.

Another Double DSD recording was a NY Philharmonic Copland Recording of the Cuban Overture, with Bernstein conducting on Columbia. It is extraordinary! You hear and feel the visceral impact of this production and the elegance of the violins. You sense the sophistication of the presentation and the mammoth right-to-left spread of the orchestra, with enormous depth of field. You hear all this and you see this tiny machine that silently—and I do mean dead silently—is sending its music to the preamp, and you wonder about how truly amazing this hobby has become!

Paul Klipsch was an avid recording engineer and loved to record jazz bands. His recordings are now available in Double DSD from High Definition Tape Transfers (http:// http://www.highdeftapetransfers.com/). They are alive with vitality and fun. No one knows who the performers are, but the results are terrific. The sound is most life-like and powerful! There is a world of musical goodies to explore with the AK240 at your command. Plus, you can put it in your pocket and take it with you!


Nothing to report of real significance. I heard no glitches or saw no strange workings of the AK240 that need fixing. I used the Toslink for audio and it works well, but does not approach wired hookup for overall sonics. Toslink rounded the edges of the music and dulled the presentation.

I am interested in the balanced 2.5mm plug I noticed in the top of the AK240. (The other port is the standard 3.5mm stereo output for headphones and the like.) I look forward to exploring its possibilities when someone produces an appropriate adapter. The single-ended adapter does not appear to compromise the sound in either of my two reference systems, or in my friend's system which included Marten Coltrane Tenors at $80,000.


The Astell&Kern AK240 Digital Audio Player is more than meets the eye or ear, with the ability to power up any pair of headphones I could find, and act as a high-resolution server in my reference system. It is the latter that has astounded me! Who needs a big hulking box and stack of stuff when the AK 240 fits the bill? Just download a program and move a file from one side of the page to the other, and you have loaded the AK 240!

Buy a gold plated adapter terminated in RCA plugs and attach your best wires to it and your preamp, and go to town!

The future is now.

Now is the AK 240! My heartiest recommendation! Robert H. Levi

AK 240
Retail: $2495

Astell & Kern