Group Test: USB gadgets (AQ Jitterbug, Uptone Regen, iFi iUSB3.0, iPurifier, iPurifier2, UPDATE on p.15…)

[bogi]

Thanks, very interesting! I would like to know, how the small iFi iSilencer performs in comparison with the cheaper devices in the test. Do you have a chance to borrow one?

[bogi]

I now see iFi brought out two new item, iSilencer and iDefender ... what are the difference?

 

Please look at preview information here

http://www.computeraudiophile.com/f30-abbingdon-music-research-ifi-audio-sponsored/english-teaser-idefender-and-isilencer-shhhh-30084/

More specific information:

http://www.computeraudiophile.com/f30-abbingdon-music-research-ifi-audio-sponsored/new-launch-idefender3-0-a-30193/

http://www.computeraudiophile.com/f30-abbingdon-music-research-ifi-audio-sponsored/new-launch-isilencer3-0-a-30194/

Comparison information also here: http://www.computeraudiophile.com/f30-abbingdon-music-research-ifi-audio-sponsored/new-launch-isilencer3-0-a-30194/#post593556

[bogi]

Getting the silencer and defender to work with the I purifier 2 and intona... Just a bit more burning in on my phones..

[ATTACH]32615[/ATTACH]

 

Sent from my SM-G900F using Computer Audiophile mobile app

That blue and light grey thing ... what is it?

[bogi]

Measurements are what they are, they arent subjective. They are just factual information.

 

Measurements are typically providing incomplete information about what we are hearing. We listen to complete sound but measurements are focused only to some concrete aspects of sound. Measured values can be considered to be objective, but we are using interpretation of measurements. That part is not so easy. Unbiased and correct interpretation, correctly considering the conditions under which measurements were done, is not always the case. So ... measurement interpretations cannot be automatically considered to be objective, it depends on people who make those interpretations.

 

Ncore1, please don't hijack this thread further. Please respect that others may have different opinion.

[bogi]

What obfuscation Is going on here? It seems more as if you want to divert away from discussing the results a potential problems with them.

 

I am not trying to silence the discussion. I appreciate that you pointed to troubles with measurements here done and that you brought your own measurements. That's fine. But as you see others have different meaning to value of listening comparisons. If discussion will continue to be only about listening vs. measurements, then you hijacked this thread.

 

IMO better when you start your own thread about relation of listening and measurements. That may lead to never ending discussion. Don't expect any common agreement.

 

I am interested in this thread and I wish it to be continued on topic.

[bogi]

This thread makes me think if USB is any good for audio at all.

 

Seems spdif, coaz or aes/ebu weren't so bad after all.

 

That's IMO too simplified view. If you would measure coax SPDIF connection you would also find computer noise. Coax cables have similar influence to sound as SPDIF cables. Why? Because they also affect noise going through them.

 

I respect your preference of multibit DACs. But most DAC models are delta sigma and most users own delta sigma DACs. Many of us enjoy DSD recordings or PCM to DSD upsampling with HQPlayer. Only USB and IIS digital transports are capable of PCM > 192k and DSD > DSD64.

 

When I bought my Gustard DAC, I bought also Gustard U10 USB to SPDIF converter. I didn't try HQPlayer yet that time, I played from foobar2000. It was quandary for me what to prefer: Coax solution with U10 and playback restricted to 192k / DSD64 or pure USB solution without such restrictions and with possibility to upsample to DSD128. I found the 2nd possibility as slightly better sounding in foobar2000 and it didn't require the U10 digital converter in the chain. When I tried upsampling with HQPlayer, it brought me further improvement step. No way back to SPDIF. The subsequent USB tweaks brought me further improvement.

 

My opinion is: These small USB boxes and tweaks are not must, but may bring further improvement in comparison with SPDIF.

[bogi]

Hi DM, thanks for the test.

Is ground transferred with the Corning USB cable? IMO yes, otherwise handshake wouldn't function even with DACs which don't require power from computer.

 

If ground is transferred, I mean a split USB cable like this plus for example iFi iPower 5V could be an interesting solution for DACs, which require power on USB port.

 

 

Would it be within your possibilities to obtain such a cable and some +5V LPS for these tests? Perhaps it could enable you also to do measurements in cases like Corning.

[bogi]

I could try, but I do much prefer things just works

 

I understand.

But you could consider my suggestion as one of products/solutions you are testing.

 

You can look to my suggestion as to AQVOX product:

The reason AQVox exists is the same why other solutions/boxes in this thread exist. It is also USB connection tweak to improve sound. It functions standalone, but it can be combined with other USB solutions too. You already tried combination of more products.

 

What's important, my experience shows that substituting computer USB power with cleaner from LPS really helps with DACs, which require VBUS +5V on their input USB port. That's majority of DACs.

 

I very appreciate your work you did till now in this thread. Please consider to add this type of solution to your test.

[bogi]

This thread insoired me to get rid of USB. I downloaded Jamcast and now stream straight to my Sony UHPH1 BRD player which has a fantastic sound. No more USB for me.

 

Many USB DACs provide fantastic sound and there is yet possibility to improve that sound. That's the view how I look at these USB gadgets. No ideal transport exists. Some form of digital transport is implemented in your BRD player and you have no access to it.

[bogi]

I agree that there are many good USB DACs, I like my Parasound ZDac very much in my desktop system. In my HT system I use the DAC's in my Marantz 7702 processor which play pretty much everything including DSD. The Sony UHPH1 was $300 and was designed for audio first. I prefer the sound streaming with Jamcast to the Sony and using its internal dacs and the analog RCA connection playing music (not movies or games). Could I do better with a USB Dac? Sure, but the SQ on the device is so good I just don't feel a desire to spend more $$$ to upgrade. I think removing the USB port from the chain is one of the reasons I got better SQ, along with the excellent DAC in the Sony. The UHPH1 BTW is a great little streamer, let's of apps, plays nearly every disc format, upscales video to either 4K or 3D, AND will play video games via a Sony Playstation game subscription.

All in all I am a happy camper!

 

The idea of combining network rendering with DAC is interesting, because it really allows to avoid USB transport. In such a case, very short internal I2S connection can be used in the place of digital transport between the network renderer and the DAC chip. It's nice to avoid USB this way.

 

On the other side, the result still depends on the concrete implementation - how much noise the network renderer spreads to the DAC chip, what's the integrity level of the signal coming to DAC input.

[bogi]

So what is the best interface IMHO? Simple, it is an audio interface originally designed for audio: I2S, with Data lines and Clock lines all separated and not interfering with each other.

 

However, I2S is an INTERNAL (means only used inside the audio device itself) audio interface standard, it is not for communication between external audio devices. A few have tried to use it for external communication in the highend audio gears (means expensive), but unsuccessful as an open standard.

 

DM, thanks for your nice comparison!

I would like to add yet information to interesting topic of I2S. I know that differential 'version' of I2S is used between boxes and that way are main drawbacks of this interface avoided, at least Sonore uses I2S successfully this way.

 

John Swenson wrote here:

Recently most implementations have shifted to a differential method (LVDS - Low Voltage Differential Signaling) sent over HDMI cables, primarily because they already exist and the cables have just the right number of wires to make this work. This LVDS over HDMI gives significantly better signal integrity than the earlier single ended implementation over S-Video connectors.

[bogi]

People who like to perform upsampling to higher rate PCM or DSD to get improved sound quality, for example via HQPlayer, are using digital interfaces which support higher rates than 192k and DSD64. Only few choices are available: USB, I2S, firewire. That means mostly USB.

[bogi]

So with this simple and cheap device, the Intona can be supplied with clean power. MacMini -> iDefender -> Intona -> Recovery -> DAC. Result: a very cost/effective SQ improvement.

 

If you would use your LPS to supply your Intona via split USB cable, probably you would reach the same result without iDefender.

[bogi]

Yes I guess a split USB cable would be an option, but would probably cost about the same or perhaps more? The iDefender 3 is cheap, with a Jitterbug like form factor. I can use my existing Curious USB cables.

I am using this one for 10 EUR + postage: Câble adaptateur USB-B pour alimentation externe USB-A - Audiophonics

You have to plug in your existing USB cable into the USB type B adaptor part of the split cable (the USB type A male of that split cable is used to inject +5V power).

 

It also breaks the earth connection from the USB source and uses their ‘IsoEarth’ technology. I don’t exactly know how this works, or what it contributes to the overall SQ improvement. But it’s another thing that is probably helping.

 

Intona performs galvanic isolation of the ground connection so I don't see a reason why iDefender placed before Intona could help.

 

I agree, iDefender is cheap and is usable instead of split USB adaptor/cable.

[bogi]

Very interesting topic ...

I use the Intona (with very good results) but will try to tweak it playing with the cleaning of the 5V using a PSU. One question I have is why can't the +5V signal be dropped in an audio only connection. I understand that the USB used the relationship between +5V and ground to match signal levels at both sides of the connection ... but couldn't this be worked around? Aren't we going to such an ache in terms of complexity just because the DACs are relying on the +5V from the source?

 

Cheers!

 

VBUS (+5V) and ground wires are required for initial protocol handshake between computer and DAC yet before any audio data is transferred. That handshake requires also data wire.

DACs are NOT relying on the +5V from the source. You can use a battery or other power supply to provide +5V to DAC USB input through split (Y type) USB cable with separate data and power branches.

There are DACs on the market which use their internal power supply for USB receiver, so they don't require +5V on USB input.

 

Other thing than VBUS is ground wire. Most of DACs require permanent ground connection between computer and DAC. Some forum members found that with some DACs after initial handshake both VBUS and ground can be disconnected. It can be possible because DATA+ and DATA- wires form a differential signal. But such a think is generally not recommended because of troubles which can arise.

 

Intona's main function is ground isolation, not cleaning of the VBUS signal. Providing clean external power to DAC USB input is easy task via clean external power source. Galvanic ground isolation of USB connection is much harder task, because the above mentioned protocol handshake must function across that isolation.

[bogi]

I don't think this is correct? On both my Chord Hugo and Ifi Nano iDSD LE dacs, neither require a 5Vbus or shielding throughput for handshake with PC. Ground, definitely.

For some DACs VBUS is not needed, but it is rather an exception. Typically VBUS is needed. Ground is always needed for handshake.

[bogi]

Hi Bogi,

I don't disagree that many DAC's need the 5Vbus, but none (that I know of) need it for handshake. Thus the 5Vbus does not need to be continuous throughput.

 

For example my Gustard DAC-X10 disconnects immediately if VBUS is not connected. I see it in XMOS Control Panel application in Windows. No handshake and no playback is possible without VBUS. I have external LPS connected permanently to my DAC via split USB cable.

[bogi]

Yes, some DACs function with USB cables, where VBUS is broken.

Although it is nonstandard USB implementation, in the case of DACs it is seen rather an advantage.

[bogi]

@DAW1d: Your trouble doesn't seem to be about USB noise. If it would be then you would hear it through headphones too. Look for a solution to avoid ground loop - probably between your speaker amplifier on some other audio component. That's other topic than this thread is discussing.

[bogi]

Look at what I have here

 

 

Looking forward to your sound comparison and measurements!

[bogi]

7 hours ago, jventer said:

Chain 2 : PC -> Oyaide continental USB 0.7m ->Icron Ranger 2214 USB Extender LEX -> Icron Ranger 2214 USB Extender REX -> Nordost Blue Heaven USB -> Recovery -> SAEC SUS480 USB -> Intona Std -> Nordost Blue Heaven USB -> DAC [MPD-3].

Recovery PSU = Stock unit supplied connected to balanced 120-0-120V supply.

 

I would try the changed order: Intona first, then Recovery. Why? Intona provides high quality galvanic isolation but is known to be not so good in output signal integrity. To improve signal integrity is Recovery USB Reclocker's main function.