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Reclocking USB signals - significant improvement !

Jim Audiomisc said:
FWIW for some time now I've used Benchmark ADCs and DACs for listening and for technical test purposes. Good kit in my opinion. Lab bench performance and useful dasblinkenlighten as well. :)
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I also have a dac2. Big fan. :):)

According to that article, it has linear supply. But the later dac3 has the switched ps, which according to some should be noisier.

Rather turns the Foo Feeders stuff on its head?

Or just opinion?
 
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Keith, He talks a great game on quality but check out the 2 devices to right of the bottom left tant caps... bridged legs..
 
Simon FYI, this is the ‘original’ Trinity design before the advent of solid enclosures and price tripling, same electronics of course.

Keith
 
Purité Audio said:
Kii make ( one) if not the best measuring loudspeaker available, do you have any evidence that Kii have skimped on their ‘power supplies’ amps in the Kiis are Hypex NCore one of if not the best measuring amplifier available.
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The thing is Keith, I sat through a Kii/BXT demo at the recent Ascot show and was shocked when their CEO, who was hosting the demo, announced that they were going to be demonstrating the speakers using the Innuos USB reclocker in their system! A guy behind me asked in a sceptical tone if the reclocker actually made any difference to which the CEO, after pausing for a moment, said it made a slight difference. He then went on to mumble somewhat uncomfortably that there are still some things about digital audio we don't yet understand and that there was more to it than just bits!

I've no doubt Innuos were subbing Kii in return for Kii plugging the product but it did make me chuckle at the suggestion that a company that started out flogging CuBox's in a hobby box powered by a linear PSU, could possibly know something about digital audio that Bruno Putzeys doesn't. :)

Presumably Putzeys was aware of this arrangement and was happy to support the notion that such a device could improve his speakers. Business is business I guess.
 
I am surprised, recently Kii have been demonstrating solely Kii, with no other products visible, they have their own ‘something’ in the pipeline.
They used to show with Innuos.
Keith
 
adamdea said:
I'm very happy to be corrected but my limited understanding is that there is no obvious relationship between the timing at which individual data are transmitted over usb with the timing at which the digital data is converted to analogue: it's not just the overall long term flow rate which asych usb allows the dac to control- doesn't usb send data in 8Khz bursts unlike s/pdif which sends a steady stream of data? If 8Khz bursts have to be converted into a steady 44.1 Khz (or 2 to the power of n multiple thereof) stream then how likely is it going to be that some fluctuation in the 8Khz bursts will make much odds? If there is no 8Khz sideband in the dac output that surely tells you something.
This means that any conceivable effect on the dacs output would be very indirect. I think this is slightly different from your point that the reclocker will always vary the amount of data per microframe, although that seems to reinforce the unlikelihood of making a material difference in the dac output by reclocking.

IIRC the next move in the chess game is some vague hand-waving about RF.

I repeat: very happy to be corrected if I have misunderstood this.
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I think you are correct [1]. That lack of any form of synchronous relationship between carrier and audio data rates means quite complex forms of adaptation if you don't have the DAC controlling the flow of data. Adapting a fixed bit rate physical layer with a fixed 125 us frame size (a burst if you like) means AFAICS the number of samples per frame has to adapt to prevent under-run or over-run. And the fixed data rate itself is allowed quite a large tolerance.

And yes. AIUI, the tell-tale for audio interference from a USB 2.0 Audio interface is a spectrum line at 8 kHz on the DAC audio output or 8 kHz sidebands. The absence of such is a good but not perfect indicator that a DAC is rejecting USB interference. However the absence could be because of the lack of this interference on the input by virtue of exceptional USB output engineering. Not likely but to be sure of a good DAC one has to check the USB interface is acting normally. I prefer to see USB DAC tests made with inexpensive USB sources to be certain the DAC is behaving properly. Fortunately these can be found so it is clear that USB interference on DAC outputs is not as inevitable as some will have you believe.

[1] I consulted the USB forum standards a while ago but having spent a short time reading them that opens up exposure to Alexander Pope's warning that "a little learning is a dangerous thing".
 
I sat through a Kii/BXT demo at the recent Ascot show and was shocked when their CEO, who was hosting the demo, announced that they were going to be demonstrating the speakers using the Innuos USB reclocker in their system! A guy behind me asked in a sceptical tone if the reclocker actually made any difference to which the CEO, after pausing for a moment, said it made a slight difference. He then went on to mumble somewhat uncomfortably that there are still some things about digital audio we don't yet understand and that there was more to it than just bits!


it's nice to know that Bruno Putzey, Kii CEO and I share the same view that a Phoenix reclocker improves the sound of the Kii 3 speakers.
I suggest the doubters, of which there appear to be many, go to the Bristol show in a few weeks and listen for themselves!
 
For similar reasons I'm not really happy with the way the 'J-Test' has continued to used as if it were a 'show all'. For spdif over a link that has, say, a poor bandwidth, it can make some sense. But as a general test of the timing behaviour of a system's output rendering it seems to me too narrow. But it seems to have become stuck in the minds of reviewers as 'the one true way' to check timing behaviour, despite the general move from spdif to USB (or even HDMI which opens a different set of cans which may contain other worms 8-] ).
 
I now have an Innuos Phoenix on home demo from my dealer . .
 
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cpg said:
it's nice to know that Bruno Putzey, Kii CEO and I share the same view that a Phoenix reclocker improves the sound of the Kii 3 speakers.
I suggest the doubters, of which there appear to be many, go to the Bristol show in a few weeks and listen for themselves!
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Yes, it certainly would appear to validate your observations wouldn't it. ;)

I'm sure Kii must've been really grateful to those clever people at Innuos. Not only do they help Kii to shift more speakers at the show, Kii also gets paid for the privilege. :cool:
 
Purité Audio said:
I am surprised, recently Kii have been demonstrating solely Kii, with no other products visible, they have their own ‘something’ in the pipeline.
They used to show with Innuos.
Keith
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Here's hoping a new speaker with Purifi drivers and amps and not a USB Reclocker.
 
Alex S said:
Fourlegs, you’re speechless aren’t you.
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I blindfolded myself, tripped over the ruddy thing and have been unconscious flat on my back for 3 hours. Hifi. You’ve just got to love it.

When I woke up everything was so inky black that I couldn’t find my way to the light switch. But then I realised I still had the blindfold on. I took it off but everything was still inky black.

My goodness this thing is good, I said to myself, before remembering I hadn’t even switched on my hifi before knocking myself out.

Maybe I’ll do some listening tomorrow without the blindfold. That will be much safer.
 
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