860 replies to this topic

[kdoot]

I just got one of these:
http://audiophilleo....iophilleo2.aspx

It's a competitor to the likes of M2Tech HiFace, Halide Bridge and MF V-Link.
- Asynchronous driverless USB supporting up to 24/192*
- Dual clocks, one for 44.1/88.2/176.4 and one for 48/96/192
- Galvanic isolation / power regeneration from USB
- "8ps or less RMS phase jitter 10Hz to 100Khz", which is top-notch
- Custom differential emitter-coupled logic output circuit instead of off-the-shelf SPDIF driver

It's the combination of all of these features which makes me think it could be "the one" to equal or beat the best CD transports. The last feature in particular means that this little box produces the cleanest, sharpest oscilloscope traces I've seen (on the web) for SPDIF sources. It is also the only USB device I've found which carefully adheres to the correct voltage level according to SPDIF specs. Others commonly go several times higher which could explain their inconsistent performance with various DACs.

Unfortunately I've made too many changes in my system all at once to give any reliable report of how the thing sounds. First impressions are positive though - I was immediately reminded of a certain "togetherness" quality I heard from a quality CD transport which was handily beating computer-based sources in a direct comparison. I'll keep posting here as I get a chance to make useful observations.

The first thing I can conclusively say is that it's cleaner at switching between frequencies than the Firestone Bravo I was using before. With the Bravo, going between 44.1 and 96kHz would cause my Rega DAC to emit some brief but nasty digital noise. That doesn't happen with the AP2.

Another thing is that the AP2 and Rega DAC get along happily at 192kHz but not so at 176.4, even though both are advertised as working at that rate. I'll be seeking support from both companies to try and get that resolved.

* 24/192 on Windows requires driver installation. Mac/Linux work out of the box.

[tricka]

Awesome. Thanks for posting and do keep us informed as you live with it for a while.

Cheerss
t

[KGJ]

Wow! Sounds promising.

Hope you manage to get the 176.4 glitch sorted. Good luck.

Looking forward to the next instalment.

[ford]

From what I have read it will not work with 88.2 or 176.4 without special usb drivers.

[obiwan]

Will have to watch how this plays out. Was thinking of getting either hailde bridge (nice simple, essentially one cord with no extra box) or the V-link to go with my mac mini. If this proves significantly better, well......

[John H. Darko]

Will have to watch how this plays out. Was thinking of getting either hailde bridge (nice simple, essentially one cord with no extra box) or the V-link to go with my mac mini. If this proves significantly better, well......

Yeah - it looks good, dunnit?

[RockandorRoll]

so where would the musiland that i have fit into the scheme of things? Ive notice these devices have really taken off since i bought mine, just wondering whether it warrants an upgrade

[kdoot]

From what I have read it will not work with 88.2 or 176.4 without special usb drivers.

From the user manual:
"There is no need for installations or configuration on supported operating systems (Linux, OSX, and Windows Vista/7). Just plug it in and the default USB audio operating system drivers should install automatically.
Note that under Linux and OSX sample rates of 44.1, 48, 88.2, 96, 176.4 and 192 are available by default. Under windows sample rates of 176.4 and 192 are only available with our custom 32 bit driver."

I'm using Mac.

[Nada]

Was thinking of getting ...... hailde bridge (nice simple, essentially one cord with no extra box)

you might want to check out the jitter measurements for the halide bridge in Stereophile online before going any further with that
the Evo might be more like a level competitor for the Audiophilleo

[chua55]

If EVO is at level with it, than I would think both are not impressive either, really.

[Listener]

kdoot.

Greenie512 has a HiFace and sometime in April I will have a V-link. Fancy a Bake-Off?

Steven.

[John H. Darko]

If EVO is at level with it, than I would think both are not impressive either, really.

Hi chua55 - you didn't like the Evo?

[kdoot]

Greenie512 has a HiFace and sometime in April I will have a V-link. Fancy a Bake-Off?

Well, I didn't want to say anything in advance, but this evening I hope to be doing a quick shoot-out with AP2 vs Audio-GD DI vs MF V-Link on some very credible equipment. Let's see how that goes, and if you want to revisit it later then that might be fun too.

[kdoot]

The time available for testing was short, but we managed to do some controlled testing of Audiophilleo 2 vs Musical Fidelity V-Link and agree on a subjective result.

Equipment was:
MacBook Pro with Fidelia, and also a Windows netbook of some variety with Foobar, 24-bit volume attenuation in software
Cheap, generic 6-foot USB cable
SPDIF interface being tested was directly attached (no cable) to BNC input on Audio-GD Ref 7 DAC
Balanced output to SGR CX4F active speakers

We were able to swap the SPDIF converters around without changing any other aspect of the system, but couldn't do it instantaneously. Had to settle for doing it repeatedly. Ben Harper's "Don't Take That Attitude To Your Grave" in 16-bit 44.1kHz Apple Lossless form was the test track.

Conclusion: the V-Link wasn't bad at all, but the AP2 was noticeably better. Once you have heard the sound of really good jitter- and noise-free digital it's easy to spot it again even though it's difficult to describe. It just sounds "better". More together. More engaging. More believable. The AP2 just seemed to deliver more of that quality than the V-Link.

As I've often said, results will vary from DAC to DAC. The Ref 7 has a pretty sophisticated SPDIF receiver and digital filter stage which levels the playing field to a substantial degree. Even so, I'm convinced that SPDIF sources benefit from being as clean, precise and stable as they can possibly be. I'm pretty happy with the AP2 so far.

[chua55]

Hi chua55 - you didn't like the Evo?

Hi

I feed the EVO with audio-gd power supply and good power cord, I cant the feel the communication factor of the singer. yes, my audio-gd cd7fv brings me closer to music than the digital playback.

[John H. Darko]

The time available for testing was short, but we managed to do some controlled testing of Audiophilleo 2 vs Musical Fidelity V-Link and agree on a subjective result.

Equipment was:
MacBook Pro with Fidelia, and also a Windows netbook of some variety with Foobar, 24-bit volume attenuation in software
Cheap, generic 6-foot USB cable
SPDIF interface being tested was directly attached (no cable) to BNC input on Audio-GD Ref 7 DAC
Balanced output to SGR CX4F active speakers

We were able to swap the SPDIF converters around without changing any other aspect of the system, but couldn't do it instantaneously. Had to settle for doing it repeatedly. Ben Harper's "Don't Take That Attitude To Your Grave" in 16-bit 44.1kHz Apple Lossless form was the test track.

Conclusion: the V-Link wasn't bad at all, but the AP2 was noticeably better. Once you have heard the sound of really good jitter- and noise-free digital it's easy to spot it again even though it's difficult to describe. It just sounds "better". More together. More engaging. More believable. The AP2 just seemed to deliver more of that quality than the V-Link.

As I've often said, results will vary from DAC to DAC. The Ref 7 has a pretty sophisticated SPDIF receiver and digital filter stage which levels the playing field to a substantial degree. Even so, I'm convinced that SPDIF sources benefit from being as clean, precise and stable as they can possibly be. I'm pretty happy with the AP2 so far.

Thanks for the write-up kdoot; as usual very informative and well-written. And to the point. (I wish I could write as directly as you do).

I'm gonna be reviewing the MF V-Link soon I think....what's the price differential between it and the AP2?

[kdoot]

I paid A$540 for the AP2 including postage with the exchange rate at just below parity. It has a 30-day money-back trial period, though I presume return shipping is at the buyer's expense.

No idea what the V-Link is worth here, sorry.

[kdoot]

Actually I want to add one more comment about the potential competitiveness of the Audiophilleo even at this price. ("Potential" until I've heard it against a great CD transport on a highly fussy DAC.)

I've been resisting USB-based audio for the past year or more because of all the crazy fussing around that was required to get the best results. I don't want to have to buy this particular kind of computer, swap the hard drive for brand X, disable standard operating features x, y and z, use only the third USB port on the left etc. I want to just plug something in which does the job properly and without any fuss. So far the Audiophilleo seems to be delivering on that while matching my sonic expectations - a combination which I suspect is pretty uncommon.

[John H. Darko]

AI want to just plug something in which does the job properly and without any fuss. So far the Audiophilleo seems to be delivering on that while matching my sonic expectations - a combination which I suspect is pretty uncommon.

I concur. The only USB converter I've heard that makes an unmistakable improvement is the J Kenny Hiface. Glad to hear the AP2 is doing likewise for you, kdoot.

[kdoot]

I concur. The only USB converter I've heard that makes an unmistakable improvement is the J Kenny Hiface. Glad to hear the AP2 is doing likewise for you, kdoot.

You should try asking Philip at Audiophilleo for a review unit. They do 30-day money back trials, so it's not too far a stretch to send one out for journalistic purposes. If that doesn't work I could probably be persuaded to loan you mine in a few weeks.

[John H. Darko]

You should try asking Philip at Audiophilleo for a review unit. They do 30-day money back trials, so it's not too far a stretch to send one out for journalistic purposes. If that doesn't work I could probably be persuaded to loan you mine in a few weeks.

That's super-kind of you kdoot. I'd be happy to send you my J Kenny Hiface in exchange. Let me contact Audiophilleo first and I'll get back to you.

[kdoot]

I spent a very enjoyable four hours or so yesterday at another SNA member's place doing direct comparisons of three DACs, three USB/SPDIF interfaces and two computer platforms with his SGR CX4Fs doing the analogue duties.

Apart from the Audiophilleo 2, the other USB devices were the Musical Fidelity V-Link and the Audio-GD Digital Interface (just "DI" from now on) with matching external power supply. I've already mentioned that in brief testing the other day the V-Link was found to be inferior but not awful and that conclusion isn't changed today. There are some new findings though.

The DI is a quality piece of kit, with excellent performance from its non-asynchronous USB implementation. Listening to 44.1kHz material we liked it better than the V-Link, which means the "you get what you pay for" rule is valid in this particular comparison. It's possible the V-Link would pull ahead with 48 or 96kHz material (because that's the native frequency family of its single crystal oscillator) but we didn't test that.

Another result of our testing was confirmation that digital SPDIF cables influence the sound. Negatively. Audiophilleo encourages you to use their product directly connected to the back of the DAC, with no cable in between. Out of curiosity we experimented with directly connecting the other devices (not easy with those big boxes, I tell you!) and also with putting a cable between the AP2 and the DAC. We didn't have much in the way of cables to play with - a Canare BNC cable supplied by Audio-GD, and a Blue Jeans digital RCA - but the effect was obvious. Avoiding cables between your USB/SPDIF converter and your DAC saves you money and gives you better sound.

It's all academic though: the AP2 directly connected to either DAC and fed from either computer delivered consistently superb results. It's so hard to meaningfully describe the sound, but a good digital transport makes fine detail clearly audible without being exaggerated, it makes tones more "beautiful", it invites you into an acoustic reality instead of throwing information at you from the other side of the room.

All I'm saying here is that it's really really good. I don't know whether it's "the best", because I haven't heard everything else. Hopefully I will be able to put it up against a great CD transport and a JK-mod Hiface in the next few weeks and will let you know how that turns out.

[John H. Darko]

This thread is becoming increasingly interesting thanks to your investigative reporting, kdoot.

[KGJ]

Thanks for the latest instalment, kdoot. A good read.

Interesting that the AP2 gave consistently superior results regarldless of which devices were in the chain. Nice and clear cut when that happens.

Do you still intend trialling it with high resolution files?

[bhobba]

This thread is becoming increasingly interesting thanks to your investigative reporting, kdoot.

+1

Hopefully when I get my JK Hiface we can indeed do that comparison. We could add the Auraliti into the mix but I am afraid I have definitely misplaced the power supply somewhere. I have had a good look for it but cant find it. I am getting a battery supply to replace it and it is pretty cheap at $30.00 so no great loss - probably will be better anyway with a battery.

Thanks
Bill

Edited by bhobba, 26 March 2011 - 11:52 AM.

[lebowski]

Kdoot, the other thing you should try is RF attenuation on the digital cable.
I have found improvement again using these simple devices.

[kdoot]

Kdoot, the other thing you should try is RF attenuation on the digital cable.
I have found improvement again using these simple devices.

What cable? The AP2 is directly attached to the back of the DAC. If you mean the USB cable, I may give it a try at some stage but both the AP2 and the Rega DAC have RF noise rejection built in so I wouldn't expect much change.

[kdoot]

Interesting that the AP2 gave consistently superior results regarldless of which devices were in the chain. Nice and clear cut when that happens.

I love it when it's like that.

Do you still intend trialling it with high resolution files?

It's flawless at 96khz. 192 works close to perfectly with my DAC, just a few glitches, but 176.4 won't sync at all. I have no way of knowing which component (including computer) is causing the trouble there.

Hopefully when I get my JK Hiface we can indeed do that comparison. We could add the Auraliti into the mix

Yeah the JK test will be very interesting. I've heard the Auraliti and based on experience as well as theory I don't think it's in the same league, because being bit-perfect and low noise isn't all it takes to be a great transport.

[bhobba]

II've heard the Auraliti and based on experience as well as theory I don't think it's in the same league, because being bit-perfect and low noise isn't all it takes to be a great transport.

I suspect you are correct. But since I have one I will check it out.

Thanks
Bill

[lebowski]

What cable? The AP2 is directly attached to the back of the DAC. If you mean the USB cable, I may give it a try at some stage but both the AP2 and the Rega DAC have RF noise rejection built in so I wouldn't expect much change.

on the coax

[kdoot]

on the coax

There is no coax cable in use here mate. The AP is not much bigger than a matchbox. On one end is a BNC socket. Connected to that is a BNC to RCA plug adaptor about 2cm long, and that's plugged in to the DAC.

[lebowski]

ahh, I see now. Sounds like a neat little unit.

Enjoy

[jkeny]

You can still put AN RF attenuator on it's SPDIF output - it's just like your BNC/RCA adaptor - worth a try for expenditure of about $20 from Minicircuits

There is no coax cable in use here mate. The AP is not much bigger than a matchbox. On one end is a BNC socket. Connected to that is a BNC to RCA plug adaptor about 2cm long, and that's plugged in to the DAC.

I'm also interested in how the AP2 & JK MK2 Hiface compare. I expect them to be similar from what I've read of the AP2.

I've been thinking of getting an AP2 for a while now because I like the approach they take in all areas except one - PS. Taking PS from the USB port is a no-no for audio, no matter how much "cleaning" up of the PS you try to do.

[kdoot]

Hi jkeny

I have to say I'm pretty skeptical about the RF attenuator idea. Where would the RF noise be coming from? The AP has a pretty good filter design on its front end and a differential output on the back. With square edge transitions of 700ps, isn't it relying on high RF bandwidth to get the job done anyway?

I do share your concern in principle about the power supply. I've been wondering whether using a USB power injector (eg http://www.emasta.co...al-hard_02.html) and a good linear 5V supply would show any improvement.

Though that would detract from the elegance of the Audiophilleo solution...

[jkeny]

Hi jkeny

I have to say I'm pretty skeptical about the RF attenuator idea. Where would the RF noise be coming from? The AP has a pretty good filter design on its front end and a differential output on the back. With square edge transitions of 700ps, isn't it relying on high RF bandwidth to get the job done anyway?

It's not about RF noise reduction - these attenuators reduce reflections that arise in the SPDIF signal path. These arise through impedance mismatches encountered by the high speed SPDIF signal i.e the risetime - the faster the rise time, the faster the signal speed, the more prone it is to impedance glitches, the more prone to reflections. 700ps risetime is fast Reflections are not good & can cause jitter. I've got some info on my website about them but there is a good thread about this on audiocircle which got crapped all over by some ****, WakiBaki (yes he is an admitted heavy dope smoker with the wrong attitude - instead of chilling it has obviously made him aggressive). Try one, they're only $20 from minicircuits in Aus or maybe someone will lend you some to try. 20dB works for Hiface but it is likely to be less for the Audiophileo?

I do share your concern in principle about the power supply. I've been wondering whether using a USB power injector (eg http://www.emasta.co...al-hard_02.html) and a good linear 5V supply would show any improvement.

Though that would detract from the elegance of the Audiophilleo solution...

Yes, I've seen reports somewhere that this greatly improves the sound! Computeraudiophile maybe?

[kdoot]

jkeny - I think based on information on the Audiophilleo website that these attenuators would be a bad idea here. For starters, the output level is just ±300mv as per the SPDIF spec, so dropping 20dB would make for a very weak signal. Also, there's this:

"Our output circuit is galvanically isolated from the computer and the rest of our curcuit, thereby allowing our output circuit to be coupled to the DAC without the use of an output transformer - without creating ground loops that can deteriorate performance. The output stage also features high return loss below 20Mhz, making signal reflections less problematic. It also exhibits very clean edges with little ringing.
SPDIF devices generally have edge transitions of about 25ns. The Audiophilleo1 supports transitions between 700ps and 15ns (in multiple user-configurable steps) in order to allow low jitter connection to the DAC without the use of a cable. The Audiophilleo2 is permanently set to high speed 700ps transitions."

[jkeny]

That's Ok, no problem, I'm not going to argue against their statements. I'm not suggesting 20dB, as I already stated, but I thought it might be a good, cheap experiment - I'm sure somebody would lend you some attenuators. I know it would seem like attenuation of the SPDIF signal away from the SPDIF spec might not be a good thing but it depends on the SPDIF receiver chip in your DAC.

I could list you lots of text from lots of product sites that state something which in reality is found not to be the case. Is it on that site or the Halide Bridge site that they state they tried batteries Vs their regenerative USB PS & found no difference You are already looking into the PS as a potential area for improvement, I just thought you were interested in experimenting? I wonder what they consider as high return loss - no figure stated?

Edited by jkeny, 27 March 2011 - 11:42 PM.

[kajak12]

I just got one of these:
http://audiophilleo....iophilleo2.aspx



It's the combination of all of these features which makes me think it could be "the one" to equal or beat the best CD transports. The last feature in particular means that this little box produces the cleanest, sharpest oscilloscope traces I've seen (on the web) for SPDIF sources. It is also the only USB device I've found which carefully adheres to the correct voltage level according to SPDIF specs.

hey kdoot any chance of posting some naked pictures of your new toy?
its a big ask against cd spinners like cd94 i really hope it does it

[kajak12]

I could list you lots of text from lots of product sites that state something which in reality is found not to be the case. Is it on that site or the Halide Bridge site that they state they tried batteries Vs their regenerative USB PS & found no difference Y

To confirm the effectiveness of our regenerative power supply, we performed a test in which we replaced this supply with batteries, and there was no improvement in jitter. Therefore USB power noise has zero impact on jitter
no mention if it improved sound marketing you must love it sometimes

[Nada]

This area of SPDIF is so complex. Perhaps this is cause SPDIF is such an inherently poor format?
All these SPDIF device are perhaps just a legacy nod that is inherently a rapidly obsoleting technology?

I reckon USB to I2S within the DAC seems like the smart way to go.

Does anyone know of any PSI sound cards that put out the equivalent of asynchronous data as I2S driven by a great clock?

[Grainy]

so where would the musiland that i have fit into the scheme of things? Ive notice these devices have really taken off since i bought mine, just wondering whether it warrants an upgrade

I recently bought the Audio-gd Digital Interface to replace my Musiland 01 USD, and after a week the Musiland has just gone back into the mix. My Audio-gd DI is noisy, I can hear the mouse move, electrical buzz etc, admittedly it is at high volumes. But the Musiland is dead quiet using same cables and USB port. Plus with the DI I have to resample 88.2Khz Hi-res files to 96Khz to play them, where the Musiland does 88.2Khz with no issue.

I could try a galvanic isolator, but thats just adding another device to the mix. I haven't contacted Audio-GD about it yet (it will still be in warranty if it's a fault), but anyone else find their Audio-gd DI noisy?

Ahh sound wise, the Musiland is more, um ... musical (but it has a couple of hundred hours under it)

[Nada]

I recently bought the Audio-gd Digital Interface to replace my Musiland 01 USD, and after a week the Musiland has just gone back into the mix.

Well that's surprising given the forum reviews of these two devices which reported the DI to be quiet and much better then the Musiland in musical flow. My DI is dead quiet. What machine and OS are you using? Is it possible your audio setting in the OS are the problem? Can you take the DI to a mate's who has computer audio set up on a different system?

You might find good advice over at head-fi as theres a long thread on the DI including set up.

Sorry to the OP for further taking this way off topic

[Grainy]

Well that's surprising given the forum reviews of these two devices which reported the DI to be quiet and much better then the Musiland in musical flow. My DI is dead quiet. What machine and OS are you using? Is it possible your audio setting in the OS are the problem? Can you take the DI to a mate's who has computer audio set up on a different system?

You might find good advice over at head-fi as theres a long thread on the DI including set up.

Sorry to the OP for further taking this way off topic

I've spent the last couple of days trying various Windows7/J.River settings with no luck. Anyone in Melb want to sample an Audio-gd DI - and test it for me at the same time? Ok. I'll now try and stop taking this OT......

Update: got a notebook and hooked it up - no buzz, even with the AC adaptor connected - Bad PSU / Ground loop in PC?

Edited by Grainy, 31 March 2011 - 07:29 AM.
Update

[eras]

Any further thoughts, kdoot? Thanks!

[lebowski]

I've spent the last couple of days trying various Windows7/J.River settings with no luck. Anyone in Melb want to sample an Audio-gd DI - and test it for me at the same time? Ok. I'll now try and stop taking this OT......

Update: got a notebook and hooked it up - no buzz, even with the AC adaptor connected - Bad PSU / Ground loop in PC?

that's good news Brendan.