Neko Audio D100 24-bit Stereo DAC

PRICE - $1,295 Direct

by

KEN WONG

&

LORIN ELIAS

 

Opinion #1 by Ken Wong

 

Neko Audio is owned by Wesley Miaow, an electrical engineer and computer scientist disillusioned by the current offering of DACs.  Tired of manufacturer claims and dubious parts quality, Wesley set out to build a reasonably priced DAC with measurable performance claims and minimal signal paths.  Tantalum capacitors are used for better performance and longevity, surface mount components offer stricter tolerances, each power pin is preceded with a pi filter to maintain independent and stable voltage and current. The 1's and 0's are processed by a Wolfson WM8804 chip, a very fine chip I might add. The signal is then fed to a pair of Burr-Brown PCM1794A chips operating in mono mode.

The majority of high-end audio DAC's utilize an active analog output stage comprised of op-amps, feedback circuitry, and additional filters. In contrast the D100 output stage is entirely passive and consists of 0.1% resistors with Jensen JT-11-EMCF transformers, a rather expensive transformer as transformers go.

d100-perspective.png

Weighing in at just over 5 lbs. the look of the D100 is rather understated and spartan.  A simple steel black case with a toggle switch on the front to choose Coaxial or Toslink with a blue indicator light and a second blue light to show the signal is locked are what you get on the front.  On the back, the IEC plug for the power cord, coaxial and Toslink inputs for input and XLR connectors for output and the master power switch. Please note that the ONLY output jack available are balanced XLR's. No standard RCA's. Adapters are available which Wesley claims does not diminish the sound, but it is a bit odd that outputs are XLR only. He sells 6' adapater cables for $26 each, pictured below. You would need a pair, of course. There is also no INPUT jack for USB, a very popular and ubiquitous choice for computer audio aficionados.

d100-rear.png

Design Notes from Wesley Miaow

"The unique aspect is the passive transformer-based output stage. A passive analog stage because was chosen avoid the possible audio degradation that can happen with an active analog stage. There are many good active designs, but there is also a lot more to analog music reproduction that THD+N measurements because music is much more complicated than sine waves.

Evidence of the passive design's benefits can be seen in the noise floor, which is at the limits of the Audio Precision ATS-2 (this is a measuring instrument that analyzes distortion) at around -130dB. This offers excellent sine-wave linearity even without feedback (as seen in the linearity graph on the web site). I wanted there to be as little as possible influencing the signal fidelity after it comes out of the PCM1794A chip. The output transformer is part of that, as well as providing a nicer solution to removing the PCM1794A output's DC offset than a capacitor which is used in other passive designs.

The dual mono implementation of the Burr-Brown PCM1794A was chosen to reduce cross talk.   The digital inputs are also spartan with Toslink and Coaxial S/PDIF inputs only.  No fancy casework no gimmicks.  The goal is to be faithful to the source; accurate, precise and clear audio reproduction with as low a noise floor as possible."

Most DAC's perform some sort of upsampling or oversampling. Some do neither. When asked about which approach he takes, Wesley replied, "The D100 does not perform upsampling but it does perform oversampling. Upsampling is the digital conversion of a lower sample rate such as 44.1kHz to a higher one such as 96kHz. Oversampling is the practice of sampling a signal at a higher rate for the purpose of digital to analog conversion. I chose not to upsample because doing so does not create any new information and, as seen in published datasheets, DAC chips perform slightly worse at higher sample rates."

 

Feature Set

 

Listening

Over the years I pretty much gave up on buying CDs and focused on my LP collection.  To write this review properly, I needed to find some modern digital music with enough resolution and detail to differentiate an opinion.  I sought the advice of a friend and he suggested the FIM k2hd sampler  This is K2 Sound! (FIMK2HD078), Jun Fukamachi At the Steinway (Take 2) LIMDX038.  I normally don’t listen to this type of music these recordings generally boring and threadbare but these performances were excellent. Recently HDTracks offered a free 24/96 sampler.  I thought I would give it a nibble to see what the buzz was about.  After listening to Misery from Dave’s True Story Unauthorized (Chesky 2000),  I was hooked, finally digital with enough flavor to satisfy.  So I went and bought the recording. 

I did a bit of research into pc audio and started fiddling with cMP, and Foobar 2000.  From what I understand cMP  is an Open Source program designed to deliver memory playback without the use of ramdisk or other utilities..  It optimizes pc resources for audio play by eliminating disk interference.  All I can say is that it works wonderfully.  I did my listening with my Theta Data Basic transport for redbook and my pc through Toslink for 24/96.

For redbook evaluation I used my Theta Data Basic Transport with the S/PDIF output to drive the D100.  I experienced some incompatibility issues since I use a Reference Line Pre-Eminence 1B balanced passive pre-amp.  The output sounded a bit slow and lifeless.  I corresponded with Wesley regarding this issue and discovered that the output voltage of the D100 was around 1.0 V and the output impedance is around 290 Ohms.  Wesley suggested that I try another pre-amp so I went to a friend’s place to try the unit out with his Cary 300 SEI integrated amplifier.  The results were similar.

I then checked the input voltage of my Sonic Frontiers Power 2 amplifier (1.25 V) and decided to drive the D100 directly into my amplifier using my Windows based pc as a transport over Toslink.  I don’t recommend anyone do this without checking the manufacturer specifications first but wanted to give the D100 a fair shake.  I optimized my pc with cMP and used Foobar 2000 as my music player.  cMP (cics Memory Player) is an Open Source program developed to optimize audio playback by eliminating disk interference.  I used the volume control on the Foobar player as the virtual pre-amp.  This gave me a glimpse into what I think the designer had in mind.  What I noticed most was the absence of noise.  The purity of the notes and the relaxed presentation emerged from a jet black background.  If you’re one who is sensitive to digital glare and not one to crave the air and ambience of the original event, then this could be the DAC you’ve been waiting for.

 

 

by 

LORIN ELIAS

I received the Neko D100 from a fellow reviewer, and our publisher asked me to provide a short "second opinion" on the unit.  Knowing that another Stereomojo reviewer (I wasn't told whom to prevent cross checking our opinions) I was somewhat apprehensive to take on the reviewing task.  A second source of apprehension was the fact that I had already read two reviews of the Neko elsewhere, and even some of the discussion board chatter.  Normally, I try to avoid reading such things about products I am reviewing in an attempt to remain unbiased.  I did not have that luxury here, but given that some of the previous information was positive and some was negative, I was not overly concerned about providing a tainted second opinion.

I am not an electrical engineer, and when reading product design specifications, I rarely read a particular detail that tells me much about how a product will sound.  The Neko D100 is a bit of an exception though.  The phrase "passive transformer-based analog output stage" actually reveals a lot about the sound of the unit. 

Assuming that the DAC already had plenty of burn-in time from a previous reviewer, I placed it immediately in my best system, consisting of a Logitech Duet transport, Musiland MD-10 DAC or Beresford TC-7520 DAC, Kimber Silver Streak interconnect to a Jungson JA-2 preamp, with Z-squared AU/AU interconnects to a Jungson WG-200 poweramp, driving Usher Be-718 speakers (the USA MusikMatters version) connected with QED Genesis Silver Spiral speaker cables. 

The "passive transformer-based analog output stage" was immediately obvious.  My Musiland MD-10 DAC is a bit "hot" from its RCA jacks.  Without any volume attenuation, it delivers 3V output, which is certainly higher than most DAC's.  From my understanding, the Neko D100 produces about 1V in output.  The most obvious result of this change is that you will find yourself MUCH deeper into the volume dial than you are used to.  Is that good or bad?  Well, that depends on the quality of your preamp, incoming power, and cables.  Raising the volume level can substantially raise the noise floor too, depending on these other factors.  It can certainly be a bad thing, but like most factors in audio, it depends...

However, there is also a huge benefit of the "passive transformer-based analog output stage".  The less "stuff" in the signal path, the less it becomes distorted, biased, or otherwise unlike how it should be.  How does that sound?  Well, like nothing at all.  This DAC has as little "sonic signature" as I have heard from any digital source.  It is not "warm" or "bright" or "lean" or "etched" or any of the other adjectives usually lobbed at digital sources.  It is as neutral as any digital source I have experienced, and coupled with an otherwise balanced system and a good recording, this is absolutely wonderful.  It produces an exceptionally clean sound, without the slightest hint of distortion.  In terms of detail retrieval, the Neko rivals the best I have heard.  Some DACs that are tilted a bit towards the treble actually fool the listener into thinking they are very well detailed.  The Neko offers no such illusion.  The presentation of detail is exceptional, and the detail is real, not illusory.  In terms of transparency, tonal balance, and retrieval of detail, this is the best DAC I have experienced.

However, there is a downside to the design.  The passive output stage has dynamic costs, especially for big dynamic changes that can sound considerably more bombastic through a DAC with an active output stage (both my Musiland MD-10 and Beresford TC-7520 easily bested the Neko in this area).  Even microdynamic contrasts seem less obvious through the Neko, and that results in music that is just a little less lively.  The DAC's ability to project a wide and deep soundstage also seems to be influenced by the passive output.  The images seemed well defined, but they don't "pop" in quite the same way as I am used to with other excellent digital sources.  Bass pitch definition was fantastic through the Neko, but it did not quite have the same heft and authority as I could enjoy with different DAC's in the system. 

I can offer one more word of caution with the Neko D100.  I (briefly) tried inserting it into mid-fi systems, without power conditioning or good cables.  Some higher-end components are not particularly snooty, and are quite capable of classing up an otherwise less engaging system.  Not so much with the Neko.  You really need a good preamp with a lot of drive, transparency, and very low noise floor to bring the signal from the Neko to life.  Without the appropriate preamp, the sound is really quite flat and lifeless.  It is still quite tonally correct, but not particularly engaging.  Pairing a $1300 DAC with a $800 system is not something most listeners would attempt, but the need for good preamplification was certainly underscored in the exercise.

In conclusion, this DAC kind of reminds me of democracy.  The best thing about it is also the worst thing about it.  In the case of democracy, the best thing about it is that everybody has a vote.  The worst thing about democracy is that everybody (no matter how  wacky, misguided, or uninformed they might be) has a vote.  To attempt to extend that analogy to the Neko, the best thing about it is that it is a passive design, without a lot of extra "stuff" in the signal path, particularly the output stage.  This results in a very transparent, clear, and "unsmeared" sound (both in terms of harmonic distortion and temporal artifacts).  The worst thing about the Neko is that it is a passive design.  Ultimately, this has costs in the dynamics and contrasts that it can muster.  If you can suffer through one more analogy, consider the example of a painting.  Most good DACs with active output stages are capable of very vivid colors, but sometimes the borders between the colours are not always clear.  The Neko is great at showing you the differences between the colours (the best I have heard in fact), but the vividness of the colors themselves is compromised. 

 

 

It is obvious that a lot of thought and great intentions went into the design of the Neko D100. A lot of superior parts as well. Be aware that connectivity is rather sparse with USB input or anything other than balanced XLR for output.

Gain matching is critical. If you use a passive preamp, this will probably not be a good match. The Neko competes with the Benchmark and the Xindak, both recently reviewed here. MusicHall has a balanced tube DAC for about $600 we'll be reviewing soon. None of those competitors are passive however. In fairness, one man's purity is another man's lack of vividness, while someone else may think too much vividness is innacurate coloration. Based on the evaluations of two different reviewers with two different systems in two different homes, we would advise you to proceed with caution regarding the Neko D100, but that is not a problem since Neko offers a free 30 day in-home trial. As in all our reviews and everyone else's for that matter, we always advise you to let your ears and your system be the final arbitor.

It is true that you will find other reviews that are more enthusiastic. All we can say is that we call them the way we hear them.

 

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