[JayNYC]

jabbr thank you for sharing your correspondence with Focusrite. I actually spoke to them in the UK yesterday and they confirmed what you just wrote. I also put in a vote for a high quality 2 channel only product.

 

[mtoc]

I did not say "external master clock".....people have to understand why some (most) of (usually asynchronous) USB interfaces is auto switching, some interfaces (some 1394) is synchronized, but asynchronous or not is a matter of choice. I don't know this rednet is asynchronous or not.

 

[rb2013]

   
Power and data running side by side is only a big deal if the power line has noise.  USB card with low noise 5V this wont be an issue.  
 
I have tried Lightspeed 10G.  Very sterile and lacking in nuance level detail.  Beaten by even the series 6 Platinum.  The full linear HDPlex PSU is the best fully ATX compatible solution I have tried.  JCAT is better than PPA V2.
 
Galvanic isolation is necessary for Ethernet because it needs to connect between rooms which might have different ground reference and therefore might create ground loop.  You can galvanically isolate USB if you like - it doesn't really help a whole lot and in my experience is a step backwards.  Even isolating the ground pin is a step backwards.  The galvanic isolation does provide some noise rejection and DC isolation but it also adds jitter.  The net gain is just not there.  Most of the good USB solution use galvanic isolation after the USB receiver, that way the PHY noise is isolated from the output.  Again the net gain is not a given.
 
What makes you think Ethernet is free from PHY noise?  In my experience NIC's put out a lot of noise.  I need to enable my NIC because I am running a headless machine.  If were not running a headless machine, I would disable the NIC as it produces much noise.
 
Secondly, have you measured the PHY noise and compared it to Ethernet, or are we just comparing one D/D implementation to another.  There are so many more factors that might be affecting the sound of the Rednet vs your USB based D/D.  Not least the quality of the reclocking, SPDIF output quality, power supplies etc.  To simply decide that the difference is 100% down to using AOIP is an assumption.  It could be valid assumption, but we would need to isolate so many other factors to make that determination.
 
I cannot account for people preferring AES/SPDIF over USB.  As mentioned the interface is a bottleneck.  If they were using LVDSI2S I would have slightly less reservations.  Impressions come from so many different setups - perhaps they have poor computer sources.  Also different systems tend to show or hide things in different ways.  Even in my own system as it develops, positions are overturned.  As resolution improved the true nature of things come out more.  What was previously observed to by detailed turns out just to be thin or harsh.  Could be that my system is still at an interstitial stage where USB appears to sound better.  However my own preference for USB came only AFTER upgrading to the HDPlex PSU and case.  We have to rationalise the world with the information we have available.  All I know is that on a technical level SPDIF is a sure bottleneck, USB evils are contingent and for the most part unverified.  LVDSI2S is much less bottleneck.
 
I used to use an external D/D until I improved my computer, but of course [computer upgrading] was costly and not possible for everyone.

>Power and data running side by side is only a big deal if the power line has noise.  USB card with low noise 5V this wont be an issue.<
 
I think many would disagree with you on this one.  What is the noise on the +5 VDC out of the JCAT?  doubt it's 1uv or less - like I achieved in my uber USB chain.
 
>I have tried Lightspeed 10G.  Very sterile and lacking in nuance level detail.  Beaten by even the series 6 Platinum.  The full linear HDPlex PSU is the best fully ATX compatible solution I have tried.  JCAT is better than PPA V2.<
 
 
That I have no doubt as it's 4X more expensive.  But looking at it - not too impressed.  Nothing special in the clocks.  On design alone would prefer a PPA V3 with ultra low noise OCXO clocking:

 

>Galvanic isolation is necessary for Ethernet because it needs to connect between rooms which might have different ground reference and therefore might create ground loop.  You can galvanically isolate USB if you like - it doesn't really help a whole lot and in my experience is a step backwards.  Even isolating the ground pin is a step backwards.  The galvanic isolation does provide some noise rejection and DC isolation but it also adds jitter.  The net gain is just not there.  Most of the good USB solution use galvanic isolation after the USB receiver, that way the PHY noise is isolated from the output.  Again the net gain is not a given.<
 
Well I think a lot of folks who have the Intona - would disagree with you.  My experience with the ICRON/Startech GB LAN Iso Audio USB extender - would say that is absolutely incorrect.  The GI this provided made a very significant difference.
 
 
>What makes you think Ethernet is free from PHY noise?  In my experience NIC's put out a lot of noise.  I need to enable my NIC because I am running a headless machine.  If were not running a headless machine, I would disable the NIC as it produces much noise.
Secondly, have you measured the PHY noise and compared it to Ethernet, or are we just comparing one D/D implementation to another.  There are so many more factors that might be affecting the sound of the Rednet vs your USB based D/D.  Not least the quality of the reclocking, SPDIF output quality, power supplies etc.  To simply decide that the difference is 100% down to using AOIP is an assumption.  It could be valid assumption, but we would need to isolate so many other factors to make that determination.<
 
Well the clocks on the F-1 (part of my uber USB chain) are the ultra low noise Crystek CCHD-575's - they look to be far superior to the ones in the JCAT card.  (do you have Phase noise numbers for that single clock?  It looks like it's only for USB.  The F-1 has three - one NDK SD ultra low phase noise for USB and then on the clean side of the isolation scheme the two separate Crystek CCHD audio clocks.  Just a much more advanced setup then the only the JCAT.  Mind you in my chain the PPA V2 card had TXCO clock for USB and was fed externally by a LPS.  And still the GB LAN isolation made a big difference, as did the W4S Recovery (also with CCHD clocks and fed by a LPS/DCiPur) - the Recovery accepts 9VDC then with ultra low noise 1uv regulators outputs 5VDC to the F-1.  Maybe you are not familiar with these devices.  This chain now has three stages of ultra low noise regulation to feed the F-1 power and on a separate data chain (using a only the data leg of the 2G) three stages of reclocking and GI.  These chains infinitely more advanced, with a far better power and data cleaning then just a PC with a JCAT card.  Really not in the same ballpark.
 
With a true TCPIP packetized protocol - all the 'mindset' issues of USB must be thrown out the window.  The PHY 'noise' is there - it just doesn't matter.  With USB 2.0 Audio Async - with the lack of lost packet error correction it very much does.  Signal intergity is critical with USB.  AOIP has full lost packet error correction.  In addition,  you have heavy levels of 8K 'packet noise' with USB (with it's analog waveform), signal integrity issues - as SI varies the AGC in the USB receive modulates to feed noise back into the PS system (much like the old DC servo laser trackers in CD players did).  Why ethernet cables don't matter as well - as long as they are of decent quality (what a relief!), like a BJC CAT6.  If someone has a ethernet filter like the Sotm ISO CAT6 filter - and wants me to try it - I would - but I really doubt any benefit.
http://www.ebay.com/itm/252404400491?_trksid=p2060353.m1438.l2649&ssPageName=STRK%3AMEBIDX%3AIT
 
John Swenson has published much on this - worth a read: http://www.audiostream.com/content/qa-john-swenson-part-2-are-bits-just-bits#zUvXZUJfW9I010L7.97
 

So now the crux of the matter, how can what goes into the USB receiver affect any of this? In several ways: packet jitter, edge jitter, PLLs. I’ll go over each of these.​

Packet jitter is the difference in the arrival time of packets to the receiver chip. USB packets are transmitted over the bus at either 1000 per second (full speed mode) or 8000 per second (high speed mode). Every time one of those packets hits the receiver a lot of activity happens inside the receiver chip. This creates lots of noise inside the chip and on the ground plane. This causes a lot of jitter on the outputs from the chip. The spectrum of this noise and jitter has a VERY strong component at either 1KHz or 8KHz, both of which are directly in the audio range. Any changes in the arrival time of the packets will change the spectrum of this packet noise. In the next installment I’ll cover what causes this packet jitter.​

 
Quote:

Next is PLLs. Every USB receiver chip has at least one if not more PLLs. These PLLs are affected by both the previous types of jitter and since almost all the circuitry inside the chip is clocked by these PLLs, the jitter on output signals and ground plane noise is going to be significantly affected by the noise spectrum coming out of the PLLs. This is filtered by the PLL loop filter, but there are still major components related to the input jitter.​

So how do we keep all this noise from the USB receiver from getting to our sensitive DAC circuits? It’s called ground plane isolation. You have separate ground planes for the USB receiver and the rest of the DAC circuitry. This DOES prevent ground plane noise from crossing over. BUT if you cut the ground plane there is no way for the return current from the signals crossing the boundary (the I2S signals and clock etc) to get between the “ground domains”. The solution is digital isolators. There are many different technologies to choose from, one most people are familiar with is opto-couplers. Some of these actually add huge amounts of jitter to the signals going through them so are bad choices for our purposes.​

A signal from the receiver now has a return current coming from the isolator so it’s happy. On the other side of the boundary there is a return current to the DAC circuitry so it is happy. BUT any jitter on the signal coming out of the isolator is STILL creating ground plane noise with a spectrum related to the jitter it had on the other side of the isolator. In addition it is containing jitter related to the isolation scheme as well, and some of THAT jitter is ALSO related to noise on the ground plane on the receiver side.​

So again the ground plane isolation and signal isolators can decrease the jitter and noise going from the USB receiver to the DAC circuits, BUT they cannot eliminate it. Some always gets through.​

Face it USB is just a very dirty technology for high end audio - and the listening proves the point.

With the AES67 Ethernet Dante and Ravenna protocols you have true IP packet level error correction, inherent galvanic isolation, no PC power corruption on the data lines, etc...
it's just a sea change in high end audio transmission.
 
>I cannot account for people preferring AES/SPDIF over USB.  As mentioned the interface is a bottleneck.<
 
Well it's funny how so many top DAC designers like Chord have no i2s on their statement sota machines - but lots of SPDIF and AES!
 
Meet DAVE:  384k on BNC SPDIF!
http://www.chordelectronics.co.uk/products-info.asp?id=98
$12,000


 

DAVE​

Chord Electronics has launched its most advanced DAC to date. Given the acronym DAVE,
Chord''s latest-generation digital-to-analogue convertor features the very best conversion technology available, using proprietary techniques never seen before.

DAVE is a highly advanced reference-grade DAC, digital preamp and headphone amplifier. Hand-made in Kent, DAVE is based around a proprietary FPGA (Field Programmable Gate Array) offering more than ten times the program capacity of its predecessor.

At its heart lies a new (and in electronics terms, huge) LX75 version of the Spartan 6 Field Programmable Gate Array (FPGA). The FPGA''s extraordinary capability enables a number of key sonic benefits including significantly improved timing and the best noise-shaper performance of any known DAC. DAVE''s technology delivers music with unmatched reality and musicality, with an unrivalled timing response.


Inputs:
USB B-style: 44 kHz to 768 kHz - DXD and Quad DSD
2x optical: 44kHz to 192kHz
1 x AES: 44kHz to 192kHz
4 x Coax: 44kHz to 384kHz
Dual-data mode available

Outputs digital:
2x ultra-high-speed coax 768kHz dual-data mode for use with future-unannounced Chord Electronics products.

Maximum output voltage: 6 volts RMS
THD and noise at 2.5 volts: RMS 0.000015 %
THD and noise at 2.5 volts: 127dBA Awt (124dBA into 33 ohms)
Dynamic range at -60 dBFS 1kHz -127 dBA A wt
(No measurable noise floor modulation, no a harmonic distortion)
(Analogue distortion characteristic: no distortion for small signals​

SPDIF - if it's good enough for DAVE (and Yggie and TotalDAC, etc...) it's good enough for me!
 
 

 

[rb2013]

And it is interesting on Darko's #1 DAC the Aqua HiFi La Scala Mk2 - he used SPDIF to do his review:
 
http://www.digitalaudioreview.net/2014/03/aqua-hifi-la-scala-mkii-dac-review/

USB reception across the swathe of budget D/A converters can best be described as a mixed bag. USB often sounds diluted when compared directly to the same DAC’s neighbouring S/PDIF feed. I start to expect more from decoders that cause financial spill above $2k so I’m pleased (and relieved!) to report that at the even loftier asking price of five thousand Euros, the La Scala’s XMOS USB input is rock solid. When directly connect to a MacMini via USB the La Scala MKII sounded no weaker than calling on the Resonessence Labs Concero HD to intercede as USB-S/PDIF middle man.​

 

Premier League ​

1. Aqua Hifi La Scala MKII

Division 1​

1. Chord Hugo TT
2. PS Audio DirectStream
3. Resonessence Labs INVICTA Mirus

Division 2​

1. Aqua La Voce S2
2. Audio-gd Reference 7.1  – [discontinued]
3. AURALiC Vega
4. Chord Hugo
5. Chord Mojo
6. Metrum Acoustics “Hex”
7. PS Audio PerfectWave DAC MKII
8. Schiit Gungnir Multibit
9. WLM Gamma

Division 3​

1. AudioQuest DragonFly Red
2. Anedio D1 [discontinued]
3. Audio-gd  Reference 10.2
4. db Audio Labs Tranquility SE
5. Eastern Electric MiniMax [discontinued]
6. Lenehan Audio (Base Level) PDX
7. Lite DAC-83
8. Metrum Acoustics “Octave”
9. Mytek Stereo192-DSD
10. Peachtree iNova [discontinued]
11. PS Audio PerfectWave DAC MKI  [discontinued]
12. Red Wine Audio Isabellina LFP-V Edition
13. Schiit Bifrost Multibit
14. Wyred 4 Sound DAC-2

Division 4​

1. AudioQuest DragonFly Black
2. John Kenny JKDAC32
3. MHDT Labs Balanced Havana
4. Resonessence Labs Concero
5. Resonessence Labs Concero HD
6. Resonessence Labs Concero HP
7. Schiit Bifrost Uber w/ Gen 2 USB

 

Division 5​

1. Astell&Kern AK120 as USB DAC
2. AudioQuest Dragonfly v1.2
3. Audio-gd NFB-2 [discontinued]
4. Audio-gd NFB-2.1 [discontinued]
5. Bel Canto DAC-3 [discontinued]
6. Bladelius USB DAC
7. CEntrance DACMiniPX
8. John Kenny JKDAC Sabre  [discontinued]
9. Lavry DA-10
10. LH Labs Geek Out 1W
11. Micromega MyDAC
12. Peachtree iDecco [discontinued]
13. Peachtree DAC*iT
14. Rega DAC
15. Resonessence Labs Herus
16. Schiit Bifrost v1
17. Stello DA100

​

Division 6​

1. Audio-gd NFB-3 [discontinued]
2. Beresford Caiman Gatorized
3. Beresford Bushmaster
4. Bel Canto DAC-1.5
5. CEntrance DACPort
6. Essence HDACC HDMI
7. Emotiva XDA-1 [discontinued]
8. Heed Dactilus w/ Q-PSU
9. HRT microStreamer
10. MHDT Labs Havana
11. Schiit Modi
12. TeraDak Chameleon

 

And the rest…​

1. Arcam rDAC
2. Audio-gd NFB-12 [discontinued]
3. Beresford 7510
4. Beresford 7520
5. Beresford Caiman
6. Calyx Coffee
7. Cambridge Audio DacMagic
8. Citypulse DA7.2x
9. Emotiva XDA-2
10. Firestone Audio Spitfire MK1 [discontinued]
11. HRT Music Streamer II+
12. KingRex UD384 + UPower
13. Devilsound USB DAC
14. Lite DAC-AH
15. Lite DAC-68
16. Maverick Tube Magic D1
17. MHDT Labs Paradisea [discontinued]
18. NAD Wireless USB DAC 1
19. Pro-ject DAC Box USB
20. Pro-ject DAC Box FL
21. Valab NOS DAC
22. Violectric V800
23. Xindak DAC5

 
 
 
And so did Srajan at 6Moons:
http://www.6moons.com/audioreviews2/aqua/1.html
 

 

Buzz-word compliance

is its de rigueur mortis and mega pixel count. It preys on misinformed consumers who shop by the numbers. Hence by mid 2014, AMR's iFi division had gone positively purple with glee to announce 768kHz PCM and DSD

octa compliance

. By then DSD256 whose very first commercial files had just begun to appear was already passé. DSD512 was the new 'in' to remind us that all life is cyclical. It spirals out of control. Then it collapses and begins anew. On cyclical, in the crusades Christianity had its holy wars. Today it's the turn of Islam. In hifi the former were the THD and IMD wars. The latter's present equivalents target digital sample rates. Faced by such accelerating madness, Aqua pray for all-out peace. Their

assalaamu a'laikum

or

pax vobiscum

is refusal to participate. Opt out. Say no to DSD and anything above 24/192. How refreshing. If John Darko's assessment had it right, this decision was far from counter-productive. Quite possibly it was the crucial enabler. Obviously neither Metrum's Hex nor Aqua's La Voce had upsampled, quadrupled or DSD'd. Yet on those I was sold already from close familiarity. Time out then from the digital hamster mill which would turn us into

octagenarians

well before our time. Mind, I'm not singling out iFi. They were simply first to hit those particular numbers. More will undoubtedly follow. That's the whole mechanism of fashion. It's a lemming brigade.

Review done by SPDIF coax input!

 

[rb2013]

I did not say "external master clock".....people have to understand why some (most) of (usually asynchronous) USB interfaces is auto switching, some interfaces (some 1394) is synchronized, but asynchronous or not is a matter of choice. I don't know this rednet is asynchronous or not.

I believe Dante designed it to not be SR Following the DVS source.  This is for studio and auditorium (rock concert) purposes - a safety measure to prevent a device on the LAN to create havoc.
 
No reason they couldn't add an internal dip switch to allow this capability - or better a Firmware upgrade version to activate.

 

[jabbr]

I believe Dante designed it to not be SR Following the DVS source.  This is for studio and auditorium (rock concert) purposes - a safety measure to prevent a device on the LAN to create havoc.

No reason they couldn't add an internal dip switch to allow this capability - or better a Firmware upgrade version to activate.

See post #225.

Just have to wait until end of August.

 

[rb2013]

See post #225.

Just have to wait until end of August.

Nice!  Chauk one up for Foobar!
 

  Please note that, for this to work in the way you desire, the playback program you are using would need to be able to change the sample rate of the playback driver (in this case, DVS). Typically, this is only possible from playback software that utilises ASIO drivers (pretty much all DAW software + some media players such as Foobar).
With the next release of RedNet Control, once the playback software changes the sample rate DVS is working at this can be configured to also change the sample rate of other RedNet devices on your network.

 

[Danutz]

REDNET D16 ordered @thomann 

 
 
 
Edit: Good to have chosen D16.... should have no windows 10 compatibilty problems (not as Redent 3 for ex.): 
 
"OS compatibilty not relevant for this product range/type"

 

[Muziqboy]

  REDNET D16 ordered @thomann 

 
And the RedNet owners club keeps on growing and growing!
 

 

[Acrobat77]

Not true i'm afraid, adding an external master clock will not create automatic sample rate switching.

Just got some additional information from Focusrite about developments that will be released in a few months that will allow it:
So with a little patience it will become available.

Cheers

That is great news, thank you for discussing it with Focusrite as it must have helped them change their minds. It was a show stopper for me but if they make this change I'm likely to try a Rednet as well once it's implemented.

 

[jabbr]

Just got news my Rednet D16 is on backorder with expected availability in the week of July 4th to July 8th.

Have to be patient a little longer

Cheers

 

[drez]

Using wordclock from DAC to control Rednet 3 or other D/D could be brilliant solution.  If they can sort out the automatic sample rate switching, and with better software/driver options.  I guess ideally also LVDS I2S...  Or just have the rednet receiver inside the DAC and have external DC power input and again grab clock from the DAC or external master clock..
 
Some of the USB transports allow for word clock input, eg. HiFace Evo 2 - also with LVDSI2S output.  Assuming a DAC with clock input I wonder how that would perform.

 

[ccschua]

Can someone pls report rgd the use of audiopc is rendered superfluous when rednet is connected ?

 

[rb2013]

Just got news my Rednet D16 is on backorder with expected availability in the week of July 4th to July 8th.

Have to be patient a little longer

Cheers

Backordered - hum...I guess we started something!

 

[rb2013]

  Using wordclock from DAC to control Rednet 3 or other D/D could be brilliant solution.  If they can sort out the automatic sample rate switching, and with better software/driver options.  I guess ideally also LVDS I2S...  Or just have the rednet receiver inside the DAC and have external DC power input and again grab clock from the DAC or external master clock..
 
Some of the USB transports allow for word clock input, eg. HiFace Evo 2 - also with LVDSI2S output.  Assuming a DAC with clock input I wonder how that would perform.

I tried the excellent Mutec MC-3+ USB with it's 1G clocking as a word clock input.  It actually made the SQ worse - it lost some of it's energy and vive.  I think the clocks in the REDNET 3 are excellent - FR also implements JetPLL to reduce jitter.  BTW used a 12in BJC BNC 75ohm digital cable for the WC hookup.
 
Now as a SPDIF reclocker the Mutec was excellent - and I have one arriving today!  Not night and day - but another 10-15% better.  But to improve on this already outstanding SQ is a major accomplishment.