Audiophilleo vs hiFace Evo... My findings, or the lack thereof.

Let me first provide a little background as to how I got here...

My initial setup was Neko Audio D100 mk2 feeding balanced into Audio-gd Phoenix, feeding into balanced Sennheiser HD-800 with a DHC Molecule balanced cable. Not a bad setup, I thought. And, given the "jitter-immune" nature of the SPDIF receiving chip on the Neko DAC, I wasn't too concerned about the SPDIF output of my PC... until I discovered that 192/24 wasn't going through properly. Then I started thinking more about reducing jitter in the SPDIF link to get 192/24 working properly.

I was able to find a hiFace Evo with TeddyPardo PSU upgrade for a good price on Audiogon, so this became my first proper "digital transport" for my PC. And wow, what a difference it made, even on the older redbook material! As many of you have experienced, cleaning up the SPDIF source really made everything come together and improved practically everything about the sound... quite contrary to the "jitter-immune" WM8804 SPDIF receiver on my DAC!

Which of course, then got me even more curious... is there further room for improvement? The comparison chart on Audiophilleo's website caught my eye... to my disappointment, the relative jitter performance of the Evo was quite horrible! "Inception" had now taken place, my Evo was only second-rate. True to the audiophile fashion, I had to try the miraculously low single-digit picosecond jitter of the Audiophilleo.

So, I found one here on Head-Fi's FS forum and just received it. Since then I've been doing some extensive A/B'ing using high-res 96/24 FLAC material played through JRiver. And here's the surprise - even though I was doing a non-blind A/B, I still couldn't differentiate the two. Even the sneaky psychoacoustic effects couldn't budge through what I was hearing... the two really sounded identical! And, this was with the Audiophilleo connected directly to the BNC jack (I replaced the RCA jack on the DAC with a BNC jack), and the hiFace Evo pumping SPDIF to the DAC through a *gasp* lowly TOSLINK cable.

So, here's my conclusion. Since my DAC has a pretty sophisticated SPDIF receiver that effectively rejects jitter (buffering and reclocking), after a certain point the SPDIF transport isn't making any more marginal difference. In other words, although the Audiophilleo may be producing technically better results than the hiFace Evo, in my particular setup where the WM8804 receiver chip is employed in the DAC, the end results (I2S signal fed to the DAC chips) are essentially indistinguishable. After all, does single-digit ps jitter matter when the jitter spec of the receiver chip is 50ps?

What do you all think? I am continuing to do my imperfect A/B testing as I type but I still cannot discern any differences. (And I need to give Neko Audio some credit back here for the "jitter-immune" claim of the WM8804 chip.)

BTW, moderators - please move this thread to the Computer Audio forum if you deem this more suited there. Thanks!

Thanks for all your replies. I have some interesting additional observations since my original post...

I got curious of the benefits of Audio-gd's ACSS connection as well as their DACs in general, so ended up picking up an NFB-1WM (purchased direct from Audio-gd, factory upgraded with TE8802 USB input) and NFB-1ES (purchased here on the Head-Fi forum). For the NFB-1WM, I chose the WM8805 SPDIF input chip over the DIR9001 as I do have some 24/192 material so the 24/96 limit of the DIR9001 would be an issue for me.

So, now I have two different DACs with the WM8804/WM8805 as the SPDIF input, and another using the Sabre ES9018 chip. And as a bonus, a TE8802 USB implementation to compare. My first test when I got the DAC units was to use them to see if I can hear the difference between the Audiophilleo and the Evo...

...and to my great disappointment, neither Audio-gd DAC would lock properly with the Evo at 24/192. Up to 24/96, it's fine, but at 192khz it all falls apart. Tried BNC, RCA, TOSLINK... Tried different cables, I even got a set of BNC 75ohm attenuators to see if that helped. And I tried this with two different Evo units to no avail. Note that all along I am using the TeddyPardo PSU so I am feeding the Evo with very clean power. Unfortunately, all I got from the DACs when playing 24/192 was either silence (Sabre's case) or loud static in addition to music (WM8805's case).

And guess what - the Audiophilleo had no issues whatsoever playing 24/192 material through either of these DACs. Both in direct-connect mode and cable mode.

What's interesting is that when I asked Kingwa about this issue, he said he tests his DACs prior to shipping with a non-Evo hiFace and his own DI unit at 24/192 and has not found any issues. Here is his quote:

Now I'm not sure what the implications of this TTL conversion stage for the SPDIF input are (can someone shed light on this topic?), but two new inferences I can draw from this experiment:

1. The Evo produces either out-of-spec SPDIF levels or too much jitter for Audio-gd DACs to register properly at 24/192, perhaps even worse than the original hiFace;

2. Despite using very similar SPDIF input chips (WM8804 and WM8805), the Neko D100 is MUCH more immune to varying degrees of SPDIF source quality than the Audio-gd NFB-1WM, so implementation around the chip seems to play a huge role.

Part 2

Now that the Evo vs Audiophilleo comparison ended rather quickly in the latter's victory, I spent more time comparing the TE8802 asynchronous USB input and the SPDIF input of the NFB-1WM to see how well the USB implementation stood up to the SPDIF implementation fed by a quality source, the Audiophilleo 2. Given that the SPDIF input is a more mature platform and the Audiophilleo is a proven (not just by me!) excellent SPDIF source, I have to admit I was biased towards the SPDIF input going into the test. After all, Audio-gd's TE8802 USB input board had no fancy looking clocks or parts, claims of technical superiority on the website (in fact Audio'gd's flagship DAC still doesn't use this input), or a proven user base who have vouched for the platform... The buyer is led to believe it's provided more as a convenience feature than an upgrade.

Anyway, I have played violin in the past, so picking out the timbre and tone of the violin sound often ends up being used to put a final stamp on my assessment.

Here's my summary, to the best of my abilities. The SPDIF through the WM8805 chip sounded rounder and less immediate, at times with less soundstage compared to the TE8802. A bit more forgiving and natural, perhaps? The TE8802 in comparison sounded more direct, with better soundstage, with everything seemingly more defined with better treble presence at the risk of sounding harsh at times. Initially though I wasn't fully convinced whether it was more actual detail of the recording coming through, or if it was jitter-induced digital artifacts causing perceived increase in treble presence (high-pitched dither like noise?) causing a fake expanded soundstage and directness of the sound. It took me a few days of listening to come to a track where a violin solo performance hit me - the song played through the TE8802 sounded real and immediate, whereas the song played through the SPDIF sounded, well, like any other recording and a bit distant. The cues that led me to this? When the bow hits the string and the string starts vibrating, with the TE8802 I was able to hear not just the note being played by the string, but all the extra vibrations that one can feel actually playing the violin - perhaps, the air around the notes as well as the notes themselves. The realism of the TE8802's presentation convinced me the direct USB --> I2S implementation of Audio-gd's DAC was not adding "fake" detail but in fact digging out more from the original material and no more. In comparison, some details were being smoothed out in the added layer of conversion in the USB --> SPDIF --> I2S process. Maybe the DIR9001 is not as lossy and that is why some still prefer this versus the WM8804/8805 despite the lack of 24/192 capability?

Anyway, long post here... if you made it this far, thank you for reading,hopefully this can stir up some interesting discussions. Once I am done with comparing the WM and ES versions of the DACs I'll post some impressions as well. This will be interesting since the power and analog sections of the two DACs are 100% identical and only the D/A conversion boards are swapped out in the two DACs. So it'll be a more objective comparison of the two chip's sound signatures, which otherwise is difficult since a DAC's sound is so heavily influenced by the components built around it...

So, responses to the responses:

Looks like you made the right choice, and while I think my experience with Audio-gd DACs is a bit dramatic (remember on my Neko the Evo was perfectly fine and performed identically to the Audiophilleo) there seem to be cases where the better-designed Audiophilleo will shine down the line. Sometimes not so obviously, sometimes VERY obviously as in my case.

So you used the Evo on Audio-gd DACs as well. Did you ever try them on 24/192 while you had the Evo? If I were to extrapolate from my experience I can totally see how the Audiophilleo made a huge positive difference on those DACs. It seems like Audio-gd's DACs just don't have a good fit with the Evo... which is odd since Kingwa himself seems to be using the original hiFace just fine.

I'll do a similar test later on my NFB-1ES which should provide similar results as yours, comparing the SPDIF input of Audio-gd's implementation of the ES9018 with the Evo and the Audiophilleo, running 24/96 or lower material of course since it can't play 24/192 through the Evo.