[Andrew_WOT]

  I had the same problem when I got my AP2. I contacted Philip at Audiophilleo, he then sent me a driver to play 24/192 and the magic came!

Was that a different one from what is available on their web site?
custom device driver v1.16

 

[Andrew_WOT]

  For anyone who might be interested in reading it, I just got my review up of the AP1 with PurePower over at Part Time Audiophile. I remain exceedingly impressed with this combo. Others are plenty nice as well - OR5 and RefLink on the higher end, iFi iLink on the lower end. But if I could take my pick of anything out there (and honestly, I can) the AP1+PP remains my top choice. 

I am having the hardest time of my life trying to spot any significant sonic differences between iFi iUSB/iLink combo and AP2+PP.
Using Chord DAC64->GS-1 (updated modules)->HD800. They both sound excellent, at first I thought that AP is more forward, now they are the same to me.

 
EDIT: Finally figured it out. AP sounds more focused with tighter bass which result in better PRAT and head boobing inducing transients. iLink is a bit more relaxed and laid back, may be even slightly diffused. But it really takes quite an effort, right material, and properly set up for critical listening test to spot the difference. AP+PP is probably 5-10% improvement over iLink+iUSB.

 

[project86]

  I am having the hardest time of my life trying to spot any significant sonic differences between iFi iUSB/iLink combo and AP2+PP.
Using Chord DAC64->GS-1 (updated modules)->HD800. They both sound excellent, at first I thought that AP is more forward, now they are the same to me.

 
EDIT: Finally figured it out. AP sounds more focused with tighter bass which result in better PRAT and head boobing inducing transients. iLink is a bit more relaxed and laid back, may be even slightly diffused. But it really takes quite an effort, right material, and properly set up for critical listening test to spot the difference. AP+PP is probably 5-10% improvement over iLink+iUSB.

 
 
Yeah, it's one of those things that some people will describe as being massive, other people will call barely noticeable. I'm somewhere in between. I figure if the differences between two good DACs can be fairly clear, then so can the differences between DDCs. But that's wearing my "analytical" hat and really focusing on differences. 
 
It also matter what DAC is used. Some of my DACs, even really good ones, don't show the differences as much as others.

 

[Tony1110]

Yeah, it's one of those things that some people will describe as being massive, other people will call barely noticeable. I'm somewhere in between. I figure if the differences between two good DACs can be fairly clear, then so can the differences between DDCs. But that's wearing my "analytical" hat and really focusing on differences. 

It also matter what DAC is used. Some of my DACs, even really good ones, don't show the differences as much as others.

Yeah, I think the Conductor, V800 etc are precisely the kind of DACs that AP2 does benefit: not so cheap as to forgo the Audiophilleo in favour of a better DAC; not so high-end that they can't be improved. If you're paying mega bucks for a DAC, you'd expect it to have similar technology incorporated without having to pay the extra for a USB interface.

 

[Andrew_WOT]

   
It also matter what DAC is used. Some of my DACs, even really good ones, don't show the differences as much as others.

Funny you said that, as on Conductor I could barely spot any difference at all, but with Chord it was much easier, I had to disable Chord buffering though.

 

[project86]

  Funny you said that, as on Conductor I could barely spot any difference at all, but with Chord it was much easier, I had to disable Chord buffering though.

 
It probably has something to do with their SPDIF input. We talk a lot about USB inputs - XMOS versus TE8802 versus VT1731 etc. But SPDIF inputs can vary quite a bit, from really good to pretty mediocre. Take a great input using something like a Wolfson WM8805 or the new TI DIX9211, with galvanic isolation for good measure. Those will be more capable than an old Cirrus CS8416 input or the like, and will allow more difference in input quality to shine through. 
 
I could be wrong, but I suspect the Conductor uses the integrated SPDIF receiver function of the ES9018 DAC chip. But they also do some funky configuration stuff with the chip where they don't use it like most others do. So that could be the problem. 

 

[Andrew_WOT]

Yeah, I think the Conductor, V800 etc are precisely the kind of DACs that AP2 does benefit:

I could be in minority who disagrees on that, except this reviewer , but using latest Burson drivers and Burson ASIO Async output I cannot detect any difference between onboard USB and AP2+PP. And to be honest I've spent significant efforts running these back to back tests, changing output in foobar2000. What I've noticed that if you spend time unplugging cables, plugging different source, restarting player, you will hear some perceived difference. But if you have two inputs connected at the same time, and quickly flip the source button on Conductor and output device in foobar2000, you won't be able to notice anything.
 
This article helped me quite a bit on principles of proper ABX testing.
http://sanderssoundsystems.com/technical-white-papers/audio-equipment-testing-wp
 
I do not discount the possibility that some computers with inherently bad and noisy USB benefit, but with two laptops I've used for tests I couldn't detect any undoubtful differences.

 

[preproman]

Hey John,
 
I have a question from reading your review.  You said this:
 
"how important is a transport? I’d say it’s very important; critical even, as long as the system is good enough to reveal differences."
 
How does this compare to the DACS that only have USB inputs ie..  QB-9, JK Ciunas?  I know you haven't heard the Ciunas yet, but what about any other USB DACs that has a very good USB implementation?  Or a good SPDIF receiver vs. a good USB receiver?
 
They're some that even do USB to I2S ie.. http://www.exadevices.com/Home.aspx not many DACs do this yet. 
 
I thought going from USB to a SPDIF receiver would induce more jitter so to speak instead of going from the USB receiver straight to the DAC.  I could be wrong.  Just would like to know the advantages and disadvantages to both.

 

[Gintaras]

Prep, i think converter purpose is to minimise jitter but good implement USB or Firewire can be as good or even better.

As regards components everything plays big role in good system, i cannot say if transport or DAC or converter or cable, from my experience everything plays pretty much high role. This is why i picked AP2 with PP unit finally. I trust good USB implementation but problem is such is usually found on higher priced units.

Anyway, only trying can tell what you will like more.

 

[project86]

  Hey John,
 
I have a question from reading your review.  You said this:
 
"how important is a transport? I’d say it’s very important; critical even, as long as the system is good enough to reveal differences."
 
How does this compare to the DACS that only have USB inputs ie..  QB-9, JK Ciunas?  I know you haven't heard the Ciunas yet, but what about any other USB DACs that has a very good USB implementation?  Or a good SPDIF receiver vs. a good USB receiver?
 
They're some that even do USB to I2S ie.. http://www.exadevices.com/Home.aspx not many DACs do this yet. 
 
I thought going from USB to a SPDIF receiver would induce more jitter so to speak instead of going from the USB receiver straight to the DAC.  I could be wrong.  Just would like to know the advantages and disadvantages to both.

 
 
Good question. It's important to remember that there's a lot going on here. See the SimAudio Moon 300D for a basic example - adaptive USB input fails the Miller Audio Research battery of tests, with sub par performance in signal to noise, distortion, stopband rejection, etc. SPDIF input passes all those tests, so that would be an obvious case where a DDC would prove beneficial. 
 
But what about DACs with async USB inputs? Aren't they immune to jitter? Well, no, some of them still have jitter problems regardless. And even if they do a good job, is it the same as a really good dedicated DDC? Probably not. But there's so much more than just jitter. Noise is a big deal, and there are many ways to approach it. The AP1 with PurePower completely isolates high frequency noise from getting into your system and causing issues. Could the same result be achieved by using a CAPS (or similar) server with a good linear PSU and the SOtM card? It's definitely a step in the right direction, but I don't know if it matches the same level of isolation. In my case I do both - why not? 
 
Basically, any DAC (USB only or multiple inputs) needs to have the USB section evaluated against the dedicated DDC to see which does a better job. For most reasonably priced DACs, it's not really a fair fight - even a midpriced DDC has more resources available to it (quality clock etc) than the USB section of a $1500 DAC. It's just a matter of allocating resources - kind of like some gear which offers a stock power supply and then upgraded versions or aftermarket versions. 
 
I'm not sold on the whole I2S thing yet. For one, it's pretty non standard in terms of format, though it looks like the PS Audio driven I2S over HDMI method is gaining popularity. But I2S was never intended to be used for external transmission - it's normally found internally, for very short runs (a few centimeters or so). Of course, "conventional" audiophile wisdom says I2S has lower jitter due to having a dedicated line for clocking info, but I have yet to see the measurements that reflect this. That same wisdom says jitter takes a hit when converted to SPDIF, yet the Audiophilleo system (and others, of course) have some crazy low measurements. 

 

[Girls Generation]

Just received t he Hiface Two so now I must compare it to the Audiophilleo 1 Will be back with findings.

 

[Gintaras]

wait for your impressions

 

[Girls Generation]

So I did some A/Bing and the most immediate differences are that the AP1 has more depth and microdetail, but the Hiface was a bit smoother, more buttery I guess. More to come~ Or not since I don't really feel bothered enough to do serious indepth A/Bing. For me, the HiFace is enough. Without having both to A/B side by side, I wouldn't even notice or even feel bothered which sounds better. It all converges and becomes a fuzzy line when you start trying compare via memory. Personally, I think I'd invest $850 in something else. AP1 is definitely a step up but for the amount of improvement, my wallet can't afford it.

 

[Andrew_WOT]

  So I did some A/Bing and the most immediate differences are that the AP1 has more depth and microdetail, but the Hiface was a bit smoother, more buttery I guess. More to come~ Or not since I don't really feel bothered enough to do serious indepth A/Bing. For me, the HiFace is enough. Without having both to A/B side by side, I wouldn't even notice or even feel bothered which sounds better. It all converges and becomes a fuzzy line when you start trying compare via memory. Personally, I think I'd invest $850 in something else. AP1 is definitely a step up but for the amount of improvement, my wallet can't afford it.

Yep, most of the times these "differences" are blown out of proportion.
Having said that I could relatively easily spot the difference between HiFace2 and iLink/iUSB combo, but till today still not sure that I will be able to tell iLink and AP2+PP apart in a blind test. They sounded identical on Burson Conductor and Chord DAC64.

 
 
Apollo, does your AP have PP or any inline USB conditioner?

 

[Girls Generation]

  Yep, most of the times these "differences" are blown out of proportion.
Having said that I could relatively easily spot the difference between HiFace2 and iLink/iUSB combo, but till today still not sure that I will be able to tell iLink and AP2+PP apart in a blind test. They sounded identical on Burson Conductor and Chord DAC64.

 
 
Apollo, does your AP have PP or any inline USB conditioner?

 
Nope, no PP because I personally think $500 for that is bs. I'd rather spend $1500 to upgrade my amp to a GSX2 or something to make much more of a difference =_= But then again, I'd spend $3000 on something more useful in my life like investments/stocks/etc. or two nice Saint Crispin's shoes hehe. But if I were tied to audio, then getting an ASW Genius 400 speaker would make much more sense. This speaker made everything I own and have owned up to now sound pale in comparison.
Plus it wouldn't be fair to the Hiface2 anyways