March Audio Posted October 8, 2019 Posted October 8, 2019 (edited) I usually avoid directly criticising other manufacturers products but this beggars belief. Given that any benefit this product may impart to bits happens upstream of this processing chain: Ethernet card-->OS kernel-->audio application-->DAC driver-->DAC-->acoustic transducer How can it possibly improve the signal coming out of the DAC? All Ethernet is already galvanically isolated. Doesnt need further isolation. Ethernet clocks are completely irrelevant. The data is error corrected. The data is buffered and passed through several processes before it gets to the DAC where the DAC word clock is asynchronous to the data. The slightest understanding of the processes involved and the application a just a tad of critical thinking shows the product to be utterly useless. Its complete audiophile foo. Edited October 8, 2019 by March Audio 3 1
aussievintage Posted October 8, 2019 Posted October 8, 2019 2 minutes ago, March Audio said: The data is error corrected. The data is buffered and passed through several processes before it gets to the DAC. This is along the lines of what I was asking, but in response to a post saying the handling of the ethernet card incoming data causes "OS jitter" . Even if that is correct, there is still buffering between the OS and the DAC. 1
March Audio Posted October 8, 2019 Posted October 8, 2019 (edited) 4 minutes ago, aussievintage said: This is along the lines of what I was asking, but in response to a post saying the handling of the ethernet card incoming data causes "OS jitter" . Even if that is correct, there is still buffering between the OS and the DAC. Absolutely. The DAC word clock, where the jitter you may see in the dac output signal is created, is not tied to the incoming data - the same advantage of USB over SPDIF. Jitter in the incoming data is irrelevant Edited October 8, 2019 by March Audio
Guest rmpfyf Posted October 8, 2019 Posted October 8, 2019 6 hours ago, Ittaku said: You see problems where I don't. We seem to have a recurring discrepancy of opinion. Respectfully disagree, but we'll have to leave it at that. Compile with tracers and measure. It's there. Done often in other fields where OS jitter is important. On your DAC/DSP rig I'd be surprised if there was any sensitivity whatsoever. Again, not everyone can make your investments, and often live with other compromises.
Guest rmpfyf Posted October 8, 2019 Posted October 8, 2019 5 hours ago, Ittaku said: Yep, any opportunity when that's what is asked, but I won't go crashing glowing reviews from people who don't ask. Just pull the eth cable and try. Most can do this. Either you hear something... Or you don't.
Ittaku Posted October 8, 2019 Posted October 8, 2019 Just now, rmpfyf said: Compile with tracers and measure. It's there. Done often in other fields where OS jitter is important. On your DAC/DSP rig I'd be surprised if there was any sensitivity whatsoever. Again, not everyone can make your investments, and often live with other compromises. Measuring OS jitter doesn't equate to noise coming out of the DAC, even without my ridiculously priced hardware. Did you measure that to show a difference or was it only the OS jitter you measured and then listened for a difference?
Guest rmpfyf Posted October 8, 2019 Posted October 8, 2019 5 hours ago, aussievintage said: I don't understand how this gets to the DAC. Let's say the DAC is plugged into the computer suffering OS jitter. Surely the design of the DAC includes a buffer, since the designer knows it is being delivered it's data from such a source. As the data is clocked through the DAC, that's where any jitter must occur if it is to be heard. Is that the problem? The clock I mean? Is it not asynchronous, relying on the buffer for isolation? Surely the design of a DAC includes a buffer? No, not really, and often not significantly. If yours does you're in the minority.
Guest rmpfyf Posted October 8, 2019 Posted October 8, 2019 2 minutes ago, Ittaku said: Measuring OS jitter doesn't equate to noise coming out of the DAC, even without my ridiculously priced hardware. Did you measure that to show a difference or was it only the OS jitter you measured and then listened for a difference? Sure - listen all the time. Differences are audible. My hardware is pretty common on the transport part - PC, USB, Amanero, I2S into DAC IC. I'm having some hardware built to buffer, reclock etc. Hopefully there are zero audible sensitivities on the 'my PC is doing stuff' end of things thereafter. There is no significant buffering in what I have. A lot do. It'll be potentially sensitive. And it can be evaluated easily.... Just pull the cable, play local and listen. If indifferent then you're winning at any price. If not, go on.
Guest rmpfyf Posted October 8, 2019 Posted October 8, 2019 47 minutes ago, March Audio said: The slightest understanding of the processes involved and the application a just a tad of critical thinking shows the product to be utterly useless. Its complete audiophile foo. Gross oversimplification of how Ethernet works.
Ittaku Posted October 8, 2019 Posted October 8, 2019 5 minutes ago, rmpfyf said: Sure - listen all the time. Differences are audible. My hardware is pretty common on the transport part - PC, USB, Amanero, I2S into DAC IC. I'm having some hardware built to buffer, reclock etc. Hopefully there are zero audible sensitivities on the 'my PC is doing stuff' end of things thereafter. There is no significant buffering in what I have. A lot do. It'll be potentially sensitive. And it can be evaluated easily.... Just pull the cable, play local and listen. If indifferent then you're winning at any price. If not, go on. I was under the impression you had a DAC with a network renderer or something and getting ethernet in. You're talking about the ethernet going to your PC only? Okay... well I haven't even heard a cheap Topping DAC affected by that one.
Guest rmpfyf Posted October 8, 2019 Posted October 8, 2019 (edited) 19 minutes ago, Ittaku said: I was under the impression you had a DAC with a network renderer or something and getting ethernet in. You're talking about the ethernet going to your PC only? Okay... well I haven't even heard a cheap Topping DAC affected by that one. Listen closer - my DAC isn't cheap and the signal chain common. Edited October 8, 2019 by rmpfyf
Ittaku Posted October 8, 2019 Posted October 8, 2019 2 minutes ago, rmpfyf said: Listen closer - my DAC isn't cheap and the signal chain common. I dunno, I listened with my headphones which are pretty resolving at length, but I'll try again.
March Audio Posted October 8, 2019 Posted October 8, 2019 (edited) 37 minutes ago, rmpfyf said: Gross oversimplification of how Ethernet works. Of course it is a simplification. What you have missed is that is of no consequence what the Ethernet does. It's totally divorced from what comes out the dac. Jitter is created by the inconsistent timing of the clock that the dac chip uses. In SPDIF this clock is regenerated from the incoming data. It can be a problem. In usb it is not. The clock is right next to the dac chip and the data is buffered from the PC. In this respect (jitter) the PC and what happens upstream is totally irrelevant Going back to this product it's obvious that whatever it does to allegedly clean up the Ethernet is pointless because you then feed into to a normal Ethernet adaptor on a pc which will have all sorts of crap going on within its ground plane. However as mentioned this just doesn't matter one jot to the data the dac chip ends up using. Edited October 8, 2019 by March Audio 1
Snoopy8 Posted October 8, 2019 Author Posted October 8, 2019 Please guys, some posts are verging on getting personal. There are lots of theories but no real listening from people without vested interest. Maybe it is hype or maybe it changes things? Until there are listening feedback and impressions,, it is premature to judge.... 1
March Audio Posted October 8, 2019 Posted October 8, 2019 (edited) 57 minutes ago, rmpfyf said: No, not really, and often not significantly. If yours does you're in the minority. Yes there is a buffer and it's data is locally clocked out to minimise jitter. Edited October 8, 2019 by March Audio
March Audio Posted October 8, 2019 Posted October 8, 2019 (edited) 2 hours ago, Snoopy8 said: Please guys, some posts are verging on getting personal. There are lots of theories but no real listening from people without vested interest. Maybe it is hype or maybe it changes things? Until there are listening feedback and impressions,, it is premature to judge.... No theories. Just understanding of how things actually work. In this case I don't think you even need very much technical understanding to see that it can't work. I just don't like Audiophile foo. Edited October 8, 2019 by March Audio 1
Ittaku Posted October 8, 2019 Posted October 8, 2019 (edited) 4 minutes ago, Snoopy8 said: Please guys, some posts are verging on getting personal. There are lots of theories but no real listening from people without vested interest. Maybe it is hype or maybe it changes things? Until there are listening feedback and impressions,, it is premature to judge.... Fair enough, but ethernet sourced noise would have to be a problem in the first place for this device to have any effect, and that's what we've been recently discussing. Whether it causes any audible problems at the moment for us in our experience. Edited October 8, 2019 by Ittaku
aussievintage Posted October 8, 2019 Posted October 8, 2019 OK, this really had me intrigued. I googled a few examples, and there is indeed a fifo buffer in DAC chips that handle USB 1
aussievintage Posted October 8, 2019 Posted October 8, 2019 (edited) I also note that the s/pdif is buffered, when being delivered via USB. Edited October 8, 2019 by aussievintage
Snoopy8 Posted October 8, 2019 Author Posted October 8, 2019 Just now, March Audio said: No theories. Just understanding of how things work. In this case I don't think you even need very much technical understanding to see that it doesn't work. I just don't like Audiophile foo. If this device came out of the blue from an unknown company & person, you may have a point. But the designer has lots of pedigree including the micro/ultra rendu. Unless he has totally lost his marbles, there may be something? Why not wait for his whitepaper to see whether our current understanding is correct or has been changed because of new research? 3
Ittaku Posted October 8, 2019 Posted October 8, 2019 44 minutes ago, rmpfyf said: Listen closer - my DAC isn't cheap and the signal chain common. Spent the last half hour with Stax SR009 headphones on a KGST amplifier fed by a Topping DX7s DAC fed USB directly from the PC, and fired up a few torrents to seed to maximise network activity, then played a few of my favourite sample tracks with and without the ethernet cable intermittently connected to my PC. I listened as carefully as I could, but I couldn't hear a difference. 3
aussievintage Posted October 8, 2019 Posted October 8, 2019 22 minutes ago, Snoopy8 said: But the designer has lots of pedigree including the micro/ultra rendu. Unless he has totally lost his marbles, there may be something? OK, I admit my ignorance. I have not heard of John Swenson, but you have mentioned his pedigree a few times now. Any links to his credentials, and what he has done?
Guest rmpfyf Posted October 8, 2019 Posted October 8, 2019 7 hours ago, rand129678 said: Error, deleted 1 hour ago, March Audio said: Of course it is a simplification. What you have missed is that is of no consequence what the Ethernet does. It's totally divorced from what comes out the dac. Jitter is the mis\ inconsistent timing of the clock that the dac chip uses. In SPDIF this clock is regenerated from the incoming data. In usb it is not. The clock is right next to the dac chip and the data is buffered rom the PC. In this respect (jitter) the PC and what happens upstream is totally irrekevant A massive oversimplification - only works if you suggest if the buffer is quite large, immune to power fluctuations, etc. I get where you're going with it - it's async, it shouldn't make a snot of difference at any rate. And even a DAC IC on I2S has a buffer of sorts - it processes parallel and yet it gets data serial. In truth these buffers are small and data upstream is packetised. Audio doesn't work on packets - it's a stream - and packets aren't filled regularly. Components emit interference which screws with others at low levels. There are differences. If there aren't for you, and you're happy with a PC motherboard USB, with SMPS everywhere and $2 cables... so be it. And you might well be. I don't think enough DAC vendors pay attention to reclocking/isolation, and I won't be buying an EtherREGEN personally. I can see how it's works for whom it does, and relative to the sea of audiophile stuff sold in it at least appears well engineered. It hits many things that could affect operation, even if IMHO some of these things are extremely esoteric and even unlikely. 28 minutes ago, Ittaku said: Spent the last half hour with Stax SR009 headphones on a KGST amplifier fed by a Topping DX7s DAC fed USB directly from the PC, and fired up a few torrents to seed to maximise network activity, then played a few of my favourite sample tracks with and without the ethernet cable intermittently connected to my PC. I listened as carefully as I could, but I couldn't hear a difference. This is an ultimate personal determinant - if you can't hear a difference, awesome. If you can, close it. Just because I can hear differences in mine or others can doesn't mean one or the other is wrong, or that one of us is dead or whatever. The internet's a great place to intone how wrong we each are though unless you've come over, flipped lids and had a listen... There's much to say and less to critique.
aussievintage Posted October 8, 2019 Posted October 8, 2019 (edited) 10 minutes ago, rmpfyf said: A massive oversimplification - only works if you suggest if the buffer is quite large, immune to power fluctuations, etc. I get where you're going with it - it's async, it shouldn't make a snot of difference at any rate. And even a DAC IC on I2S has a buffer of sorts - it processes parallel and yet it gets data serial. In truth these buffers are small and data upstream is packetised. Audio doesn't work on packets - it's a stream - and packets aren't filled regularly. There are also other buffers in the chain. The humble USB system is quite complicated, not just a new RS232. The chipsets and drivers that are involved in USB communication implement buffers for each endpoint. This is upstream of the FIFO in the DAC. There is much that ensures the buffers that matter are "filled regularly". Edited October 8, 2019 by aussievintage
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