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Post by novisnick on Nov 29, 2018 22:00:49 GMT -5
Alas, the head of the LSU Supercomputing department was unable to attend supper this evening, but the technical manager for our LPB station was. He and I discussed the Microrendu in depth (and data transfer protocols, and video/audio streaming, etc.), and he is in the shoes of KeithL who can't wrap his head around how any bit-perfect stream could possibly sound different from any other. It's Don's opinion that the Microrendu os tailoring the bits and that what's coming out is NOT what went in. I don't know how to test that theory, but if we can figure it out, I'm willing to try it. To be a valid test, I'd have to get the bitstream off the Ethernet cable and compare it to the Microrendu's USB output. If I can accomplish this without buying test equipment, then I'm ready to go! Boom It has to be one of two things: 1) the rendu line and the like are "tailoring" the bits in a (almost universally in a positive way for all systems) favorable way. 2) other systems are messing up the bits in some way, and rendu series and the like are not messing them up. I bet on #2. And, even if #2 is right...a measurement "might say" the bits are the "same". It's all about measuring the right thing in sufficient discrimination. Mark Perhaps delivering data in packets via ethernet makes for better music. Packets and a better word clock making delivery more accurate without having to resend as often which slows the process down and adds jitter to the equation. |
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Post by monkumonku on Nov 29, 2018 22:42:47 GMT -5
Alas, the head of the LSU Supercomputing department was unable to attend supper this evening, but the technical manager for our LPB station was. He and I discussed the Microrendu in depth (and data transfer protocols, and video/audio streaming, etc.), and he is in the shoes of KeithL who can't wrap his head around how any bit-perfect stream could possibly sound different from any other. It's Don's opinion that the Microrendu os tailoring the bits and that what's coming out is NOT what went in. I don't know how to test that theory, but if we can figure it out, I'm willing to try it. To be a valid test, I'd have to get the bitstream off the Ethernet cable and compare it to the Microrendu's USB output. If I can accomplish this without buying test equipment, then I'm ready to go! Boom It has to be one of two things: 1) the rendu line and the like are "tailoring" the bits in a (almost universally in a positive way for all systems) favorable way. 2) other systems are messing up the bits in some way, and rendu series and the like are not messing them up. I bet on #2. And, even if #2 is right...a measurement "might say" the bits are the "same". It's all about measuring the right thing in sufficient discrimination. Mark Well maybe the MR is doing to bytes what tubes do to an audio signal - adding distortion. Like when digital came on the scene many people complained about CD's being too "sterile," possibly because of the precise nature of 1's and 0's compared to analog. So maybe you are preferring a distorted sound that takes the "sterility" out of the original stream by adding harmonic distortion. Rather than cleaning up what comes out of the digital signal it is actually adding some fuzz. Maybe it is adding some 1/2's in there (1/2 is analog; .5 is digital just like 1/3 is analog and .3333333333333333 is digital), so you prefer the sound just like some folks prefer vinyl over CD's. Or tubes over SS. |
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Post by mauriceminor on Nov 29, 2018 22:59:43 GMT -5
What's old is new again . . .
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Post by Boomzilla on Nov 30, 2018 2:04:35 GMT -5
What's old is new again . . . I'm still waiting for that to apply to ME! LOL |
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Post by novisnick on Nov 30, 2018 2:27:33 GMT -5
What's old is new again . . . I'm still waiting for that to apply to ME! LOL  |
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klinemj
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Post by klinemj on Nov 30, 2018 5:55:31 GMT -5
It has to be one of two things: 1) the rendu line and the like are "tailoring" the bits in a (almost universally in a positive way for all systems) favorable way. 2) other systems are messing up the bits in some way, and rendu series and the like are not messing them up. I bet on #2. And, even if #2 is right...a measurement "might say" the bits are the "same". It's all about measuring the right thing in sufficient discrimination. Mark Well maybe the MR is doing to bytes what tubes do to an audio signal - adding distortion. Like when digital came on the scene many people complained about CD's being too "sterile," possibly because of the precise nature of 1's and 0's compared to analog. So maybe you are preferring a distorted sound that takes the "sterility" out of the original stream by adding harmonic distortion. Rather than cleaning up what comes out of the digital signal it is actually adding some fuzz. Maybe it is adding some 1/2's in there (1/2 is analog; .5 is digital just like 1/3 is analog and .3333333333333333 is digital), so you prefer the sound just like some folks prefer vinyl over CD's. Or tubes over SS. That's an example of what I mean by #1. But honestly, I don't think what I am hearing is that. By comparison, the rendu sound seems like distinct notes vs. the non-rendu sound having notes smeared together...like they were not properly rendered. It's almost like 780p vs. 4K image, but in sound. With adding distortion, I'd not expect that. Mark |
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Post by brutiarti on Nov 30, 2018 7:38:25 GMT -5
Interesting discussion here. I would totally try a MR but I don’t stream music. Just a question for the believers, when you were using a PC as streamer was it connected using ethernet cable or Wi-fi?
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Post by mountain on Nov 30, 2018 8:17:04 GMT -5
Interesting discussion here. I would totally try a MR but I don’t stream music. Just a question for the believers, when you were using a PC as streamer was it connected using ethernet cable or Wi-fi? I stream music with MacBook Pro (Roon/Tidal) to Oppo 105 usb dac via Wi-fi. I do not have any streaming problems, no drop outs, connection problems, etc. I have been following these discussions and wonder if the ultra Rendu would be benefitial between the laptop and dac using wi-fi. Of course small green computer said yes it would, but would even be better with the sonictransporter i5. Money, money. I passed on Black Friday sale, don’t want to run Ethernet if I don’t have to due to proximity limitations, cost, and laziness 😁. But I’m listening. |
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Post by Soup on Nov 30, 2018 8:23:31 GMT -5
Finally convinced myself to pull the trigger on the Ultrarendu....went to Small Green Computer website for the special deal...all sold out. I so wanted to do a comparison between the Rendu and the Bluesound Node 2i... Give Andrew a call and see if he will let you back order one at the special price? |
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klinemj
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Post by klinemj on Nov 30, 2018 9:03:27 GMT -5
Interesting discussion here. I would totally try a MR but I don’t stream music. Just a question for the believers, when you were using a PC as streamer was it connected using ethernet cable or Wi-fi? Mine was ethernet cable. Mark |
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Post by brubacca on Nov 30, 2018 9:49:56 GMT -5
When I used a PC all my music was local on the SSD.
The only thing that went over the network was control signals.
I was wireless (using the same Ethernet bridge I am using now)
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DYohn
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Post by DYohn on Nov 30, 2018 16:00:53 GMT -5
As a *bleep* engineer I was an objectivist and a science only guy for years. All I say now is trust your ears and to heck with theory it is wrong. Welcome to the club.
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Post by liv2teach on Nov 30, 2018 17:24:09 GMT -5
Finally convinced myself to pull the trigger on the Ultrarendu....went to Small Green Computer website for the special deal...all sold out. I so wanted to do a comparison between the Rendu and the Bluesound Node 2i... Give Andrew a call and see if he will let you back order one at the special price? I couldn't find a phone number on the website. I did contact them via Facebook and whoever wrote back, said they would check in the warehouse and see what they could do. |
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KeithL
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Post by KeithL on Nov 30, 2018 17:44:34 GMT -5
There is no conceivable way in which delivering music via Ethernet packets could "make it better". That's sort of like suggesting that you could make a painting better by running it through a shredder and then reassembling the pieces. At best, if the process works perfectly, which it usually does, you could hope to do no noticeable harm. (Unless you like impressionist paintings... then who knows?  )
Ethernet does provide some degree of isolation. However, since the Rendu is the "computer", and the Ethernet link isn't between it and the DAC, that doesn't make much sense either.
Providing a different and better clock to the DAC could conceivably make an audible improvement.
A lot of that would depend on several factors - including how good your clock was, how accurately it's delivered to the DAC, and how able the DAC is to take advantage of the improvement.
It's quite possible that SOME other systems might mess up the bits in various ways. However, where and how that can happen depends on a lot of specific details. For example, when I send a file to a USB hard drive, the integrity of the file is verified. Likewise, when you transfer a file over an Ethernet connection normally, several levels of verification are involved. HOWEVER, if you're using a protocol like DLNA, it's hard to tell how well they're handling that part of the deal. And, generally, unless something is terribly wrong, the computer will deliver all the bits to the DAC over an asynchronous USB connection without losing any.
(And, generally, if something is terribly wrong, the result will be obvious dropouts.)
If anything, it seems most likely to me that the galvanic isolation on their output actually performs very well, and sometimes helps.
It has to be one of two things: 1) the rendu line and the like are "tailoring" the bits in a (almost universally in a positive way for all systems) favorable way. 2) other systems are messing up the bits in some way, and rendu series and the like are not messing them up. I bet on #2. And, even if #2 is right...a measurement "might say" the bits are the "same". It's all about measuring the right thing in sufficient discrimination. Mark Perhaps delivering data in packets via ethernet makes for better music. Packets and a better word clock making delivery more accurate without having to resend as often which slows the process down and adds jitter to the equation. |
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Post by brubacca on Nov 30, 2018 17:55:37 GMT -5
Its probably just good old electrical engineering.
Possibly that Crap sounding computer or Rapsberry Pi is built to computer specs and standards and not audio standards. My understanding is that audio designers take special care in running their wire traces and isolating the different power supplies. Perhaps all we are hearing is audio component, designed to be an audio component excel at its job. A Rapsberry Pi and Regular computer probably just aren't built to the same standards.
Its not like Emotiva has a computer inside the ERC-3 and just loads a CD driver. Its an optimized circuit board layout for the best sound. Same argument. I'll bet a ERC-3 just used as a transport to an external DAC would sound better than some random computer running Linux or Windows with a CD drive.
Isn't this the same thing? Why sell CD players when any computer can be just as good a transport with any $25 optical drive?
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KeithL
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Post by KeithL on Nov 30, 2018 17:57:25 GMT -5
I'm not specifically suggesting that this is the case....
However, one of the ways in which people generally describe the audible effect of EXCESSIVE jitter is: "a softening and slight blurring of transients and high frequencies". I would say that one of the audible effects of lowering jitter tends to be exactly what you describe - although it is very subtle at any reasonable levels. (I can also see how some folks might consider either to "sound better" with some content and some speakers.)
It seems somewhat unlikely that they would alter the bits - and then lie about doing so (their credibility would be destroyed once someone found out).
However, as an aside, added second harmonic distortion, of the sort added by tubes, is said to actually IMPROVE INTELLIGIBILITY in audio content.
Some high-end public address equipment, and some hearing aids, actually add second harmonics as a way of making voices more intelligible.
If you've heard Blue Bayou by Linda Ronstadt.... you may recall that the voice cuts through everything else and almost seems to sit on top of the music. That effect was done by an Aphex Aural Exciter... which adds second harmonic distortion in precisely controllable amounts (perhaps turned up a teensy bit too high that time  ).
Well maybe the MR is doing to bytes what tubes do to an audio signal - adding distortion. Like when digital came on the scene many people complained about CD's being too "sterile," possibly because of the precise nature of 1's and 0's compared to analog. So maybe you are preferring a distorted sound that takes the "sterility" out of the original stream by adding harmonic distortion. Rather than cleaning up what comes out of the digital signal it is actually adding some fuzz. Maybe it is adding some 1/2's in there (1/2 is analog; .5 is digital just like 1/3 is analog and .3333333333333333 is digital), so you prefer the sound just like some folks prefer vinyl over CD's. Or tubes over SS. That's an example of what I mean by #1. But honestly, I don't think what I am hearing is that. By comparison, the rendu sound seems like distinct notes vs. the non-rendu sound having notes smeared together...like they were not properly rendered. It's almost like 780p vs. 4K image, but in sound. With adding distortion, I'd not expect that. Mark |
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KeithL
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Post by KeithL on Nov 30, 2018 18:02:39 GMT -5
There only one reason why that doesn't make as much sense as it may seem to.
The Rendu is in fact a purely digital device.... it doesn't HAVE any analog circuitry.
It accepts digital data at its Ethernet input... And outputs digital data at its USB output... There are no actual components inside the Rendu that are processing or handling analog signals. (What you said would make perfect sense if it contained the DAC - or any of the other analog circuitry.)
Other than having a heavy duty transport and powerful LASER to help read less than perfect discs... All of the optimizations in the ERC-3 that actually affect the sound are related to the DAC and the analog circuitry.
Its probably just good old electrical engineering. Possibly that Crap sounding computer or Rapsberry Pi is built to computer specs and standards and not audio standards. My understanding is that audio designers take special care in running their wire traces and isolating the different power supplies. Perhaps all we are hearing is audio component, designed to be an audio component excel at its job. A Rapsberry Pi and Regular computer probably just aren't built to the same standards. Its not like Emotiva has a computer inside the ERC-3 and just loads a CD driver. Its an optimized circuit board layout for the best sound. Same argument. I'll bet a ERC-3 just used as a transport to an external DAC would sound better than some random computer running Linux or Windows with a CD drive. Isn't this the same thing? Why sell CD players when any computer can be just as good a transport with any $25 optical drive? |
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KeithL
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Post by KeithL on Nov 30, 2018 18:11:21 GMT -5
Interesting.
I tried to look up exactly how RAAT works ....
But, according to the posts on various Roon forums, it has changed a lot over time, and continues to "evolve". While I've seen various "lists of priorities and goals" I can;t find any specifics about levels of error correction. Therefore, it's quite possible that RAAT may be sensitive to all sorts of things (and, without those details, it's difficult to even guess what they might be). So, for example, I don't know if it may choose to send reduced quality content to avoid a total audio loss in the event of a network slowdown.)
Without doing a lot more research I would have to consider RAAT in much the same way as I consider DLNA... It's a sort of black box - and the details of what's going on inside are simply not available to us...
Also KeithL - re. DLNA...note that many of us reporting the sound improvements are not using DLNA. We're using Roon, which uses RAAT. So, what we're reporting is not some weird effect of DLNA. And, I didn't find any difference between Roon and other music players (like jRiver or direct via Tidal) when Roon and the others came from a PC to my DAC. I only find the difference when I go Roon to the rendu players. Mark |
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Post by Casey Leedom on Nov 30, 2018 18:23:40 GMT -5
KeithL, as far as I know, the Roon Advanced Audio Transport doesn't perform any signal processing itself. It's a coordination protocol which is used between Roon Cores (Servers), Controllers, and Bridges (AKA Endpoints). It is unfortunately fairly fluid since they insist that all components use the same version of RAAT at the same time and can thus avoid having to maintain binary compatibility. Hopefully they at least version the protocol headers ala Remote Procedure Call systems. There is Error Correction in RAAT, but as far as I know, only in the sense that it runs over TCP[1,2]. Now, that said, there is resampling in the Roon Core. If the Digital Audio Asset is in a format that the Ausdio Device attached to the Roon Bridge can't handle, the Roon Core will translate the Asset into the "closest" that the Audio Device can handle. When you look at the "Audio Path" display in the Roon Controller, it will show you all of this. Casey [1] June 7, 2017, Roon 1.3 (Build 234) Is Live![2] June 8, 2017, Roon Switches From UDP to TCP
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Post by foggy1956 on Nov 30, 2018 19:19:43 GMT -5
Interesting.
I tried to look up exactly how RAAT works ....
But, according to the posts on various Roon forums, it has changed a lot over time, and continues to "evolve". While I've seen various "lists of priorities and goals" I can;t find any specifics about levels of error correction. Therefore, it's quite possible that RAAT may be sensitive to all sorts of things (and, without those details, it's difficult to even guess what they might be). So, for example, I don't know if it may choose to send reduced quality content to avoid a total audio loss in the event of a network slowdown.)
Without doing a lot more research I would have to consider RAAT in much the same way as I consider DLNA... It's a sort of black box - and the details of what's going on inside are simply not available to us...
Also KeithL - re. DLNA...note that many of us reporting the sound improvements are not using DLNA. We're using Roon, which uses RAAT. So, what we're reporting is not some weird effect of DLNA. And, I didn't find any difference between Roon and other music players (like jRiver or direct via Tidal) when Roon and the others came from a PC to my DAC. I only find the difference when I go Roon to the rendu players. Mark Sounds like more of that secret sauce😎 |
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