Howlar Posted June 1, 2009 Share Posted June 1, 2009 [Howlar's thread on the Squeezebox Duet veered off into a discussion on computer-based audio. Here is that discusion - AudioEnz] Link to comment Share on other sites More sharing options...
Antipodes1553552706 Posted June 29, 2009 Share Posted June 29, 2009 I am comparing five different 'transports'. Two of them are conventional CD transports and the other three are different ways of providing the same output you get out of a CD transport, but from music stored on a PC. These latter three ways are quite different from one another, and each have their proponents. At the one extreme, the Transporter (like its sibling Squeezebox) is quite independent of the performance of the PC because of its use of ethernet, meaning the PC can be common or garden variety and used for other things. At the other extreme, the Cics player is all about doing it in the PC and how to optimise that, or overcome the inherent problems of PCs as music servers. The Offramp sits in between. By using USB, buffering and reclocking, the Offramp is less independent of the PC than the Transporter, and the PC needs to be optimised to a degree, but less so, and interestingly optimised in a different way to the Cics PC. The Cics thing is based on XP Pro, but I prefer the Offramp with Vista, and it doesn't really matter with the Transporter. With Vista I have experimented with disabling many many services and I have probably altered around 70 settings now. Some have made a dramatic improvement to refinement and reduced grain, but its amazing how much faster everything works on this PC now. I am about to experiment with Windows 7 and suspect, from talking to a few contacts I have in Redmond, that it will be superior to both Vista and XP. I think I am convincing myself that the Cics way is not the best. It is fraught with issues such as the rapid obsolescence of the parts and the need to re-optimise for contemporary parts too often - but the keen DIYer could have a lot of fun with it. I am more and more convinced that ethernet is the way to go, not USB. And I am thinking Empirical have just done a better job with the Offramp than Logitech have done with the Transporter, for now. Which is not to disrespect Logitech or the previous owners as there are reasons why ethernet takes a lot more know-how to exploit its inherent advantages. Frankly, if you don't want to dedicate a PC to the task or play with configuring PCs - buy a Transporter. If you don't mind dedicating a PC and attending to some of the detail of how that PC is made up and configured, then the Offramp can beat the Transporter. Not by a lot, but as with everything one person's gnat's whisker is another's country mile. And, of course, there is the issue of having to have a PC in proximity to your stereo with the Offramp and you don't with the Transporter. Where the Transporter is let down is with its DAC and audio stage, where you can do a lot better in my opinion. I guess that is where the Modwright version comes in. This is such a big topic, and fascinating to me at the moment, but I am sorry feckless, explaining all of it would be a very big post indeed. Link to comment Share on other sites More sharing options...
Matthew Masters Posted June 29, 2009 Share Posted June 29, 2009 Antipodes;95326 wrote: This is such a big topic, and fascinating to me at the moment, but I am sorry feckless, explaining all of it would be a very big post indeed. I wasn't looking for more verbiage, merely clarification of the terms you'd used. Having said that, I'd be truly fascinated to hear why you believe Ethernet is an inherently better connection method than USB (or wireless for that matter). f Link to comment Share on other sites More sharing options...
tigi Posted June 29, 2009 Share Posted June 29, 2009 verbiage Verbiage?! This is singularly the most useful and considered comparison of (what i consider) the most interesting products currently offered for computer based transports that I have ever come across. One could spend months of research and many $$$$ trying to a form a reasonable comparison of these products and still not achieve anywhere near the thoroughness and skill that has been applied here. Thank you Mark! Link to comment Share on other sites More sharing options...
Matthew Masters Posted June 29, 2009 Share Posted June 29, 2009 534 words to say he thinks that USB is inferior to Ethernet and that the CIC PC thing is superior to the Logitech Transporter. No particular justification for either opinion, and bugger all entertainment value in reaching them. Considering all I actually asked for was a clarification of terms, and he barely managed that, I stand by verbiage. f Link to comment Share on other sites More sharing options...
kaka Posted June 29, 2009 Share Posted June 29, 2009 Antipodes;95326 wrote: I am more and more convinced that ethernet is the way to go, not USB. And I am thinking Empirical have just done a better job with the Offramp than Logitech have done with the Transporter, for now. That is interesting - obviously there are any number of music playing software products that can hurl bits down a USB, but are there many that handle ethernet (Slimserver is the obvious one) ? That would be relevant if anyone was to make a serious attempt to engineer a ethernet to SPDIF/I2S interface, with no extras and no component or power supply compromises. Link to comment Share on other sites More sharing options...
Antipodes1553552706 Posted June 29, 2009 Share Posted June 29, 2009 There are many differences between the interfaces - ethernet, USB, Firewire, SPDIF and AES/EBU. And then there are variants within them such as wired ethernet and wireless ethernet, or coax SPDIF and optical SPDIF. And so how you see one as being superior to another depends on what you think the ideal overall strategy is and what is important in implementing that strategy. One strategy that makes a lot of sense to me is to use asynchronous protocol. This allows you to locate the master clock at the DAC, which is clearly the best place for it to be. Neither Firewire, SPDIF or AES/EBU use asynchronous protocol which means the master clock is in the computer, and then this information must be kept intact all the way to the DAC. Of course it isn't kept intact and that is why various things such as PLLs are used as band-aids to reduce jitter. Ethernet uses asynchronous protocol and some USB interfaces use it too and so they are capable of superior flow control. Ethernet, whether wired or wifi, has the flow control and retry tools required so that the only task is to get the data from the computer to the device without bit errors. You can therefore put a large buffer at the receiving device and clock the data out of the buffer straight into the DAC (which is how the Transporter and Squeezebox work). Also in favour of the Transporter and Squeezebox is that purpose built audio software can be located with the DAC. No timing information needs to be sent from the computer to the device. The data is not streamed in near real time as it is with USB, Firewire, SPDIF and AES/EBU. Instead it is packetised and sent in high speed bursts - which brings up the issue of bandwidth. Ethernet wins hands down on bandwidth. And on top of all that, with ethernet it is just a matter of sending the data. The PC audio stack is bypassed altogether, unlike with the other protocols. The Microsoft and Mac audio software stacks are not terribly easy to work with to get good audio and will probably have to improve a lot before the PC based players such as Foobar and iTunes can really perform the task well, and/or become more flexible to work with. With the existing OSs certain decisions have been made that may or may not work well with your music files. For example, you may have 16 bit data files but Vista must re-dither it to 24 bit before it can stream it. These are just my opinions and in forming them I have been influenced by the opinions of people that have done a lot more work in this field than I have, and there is room for different opinions about what is important or ideal using the same set of facts. For example, some will tell you jitter is irrelevant and an imagined enemy of audiofools, so much of what I have said above would be on a false premise. Link to comment Share on other sites More sharing options...
Antipodes1553552706 Posted June 29, 2009 Share Posted June 29, 2009 What verbiage don't you understand? Link to comment Share on other sites More sharing options...
Antipodes1553552706 Posted June 29, 2009 Share Posted June 29, 2009 Sorry to be boring, but to go one step further with my conclusions so far. Where I would like to see things go is for DAC manufacturers to engineer ethernet and player interfaces into them. Or alternatively, for USB interfaces to evolve (some of them are already there) to meet similar standards as ethernet and for the OS audio stacks to become more friendly to quality streaming of different audio files. Link to comment Share on other sites More sharing options...
tanman_sg Posted June 29, 2009 Share Posted June 29, 2009 This is an interesting discussion of a topic central to the future of HiFi technology. In which case I prefer more words. I'd hate to make an incorrect assumption based on just a few. Perhaps another thread to compile ideas more clearly? Link to comment Share on other sites More sharing options...
curiousgeorgenz Posted June 29, 2009 Share Posted June 29, 2009 Antipodes;95339 wrote: Sorry to be boring, but to go one step further with my conclusions so far. Where I would like to see things go is for DAC manufacturers to engineer ethernet and player interfaces into them. Or alternatively, for USB interfaces to evolve (some of them are already there) to meet similar standards as ethernet and for the OS audio stacks to become more friendly to quality streaming of different audio files. Have a look at the new PS Audio Perfect Wave DAC and Transport. Definitely some new thinking there. http://www.psaudio.com/ps/products/ Interested in your thoughts. Link to comment Share on other sites More sharing options...
nixon76 Posted June 29, 2009 Share Posted June 29, 2009 I2S via HDMI though? Golly. You'd hope they would have seen that RJ-45/cat5e/6 was already being used in several places. To me the Chord Electronics QBD76 (http://www.chordelectronics.co.uk/products_detail.asp?id=52) is an equally clever piece of kit me thinks. Got a really good review in one of the main mags - can't find it though. Re the things that Antipodes talks about - esp Ethernet - you can find them here: http://www.positive-feedback.com/Issue41/ca_nugent.htm Link to comment Share on other sites More sharing options...
Ernie1553552694 Posted June 29, 2009 Share Posted June 29, 2009 Antipodes;95339 wrote: Sorry to be boring, but to go one step further with my conclusions so far. Where I would like to see things go is for DAC manufacturers to engineer ethernet and player interfaces into them. Or alternatively, for USB interfaces to evolve (some of them are already there) to meet similar standards as ethernet and for the OS audio stacks to become more friendly to quality streaming of different audio files. That's a big killer for a lot of people: the lack of decent interface for control. Yes, the control side of things is here, but these interfaces are usually associated with big $ custom installation brands like Crestron and AMX. Sonos addressed this issue at a consumer level from the outset back in 2005 with a nice controller and ethernet streaming -- meaning it's a lot cheaper than the 2 brands mentioned above. Logitech has trailed behind with these ideas ever since and has mainly captured the "value" end of the market. Transporter not withstanding. Why we don't see more devices able to handle all the different flavours of files is down to a cost thing and licensing of codecs for the various devices. Not a lot of companies have pockets deep enough. Take Linn for instance, they have offloaded the cost of interface development by making the interface and the main set of codecs open source. You'd think otherwise, but then again Linn's core competencies are not with software development. It's easy enough to design and manufacture DACs of however many hardware interface flavours may be out there, but to do so with the human interface that works requires some genius. Link to comment Share on other sites More sharing options...
Antipodes1553552706 Posted June 29, 2009 Share Posted June 29, 2009 Which is why the ethernet interface does not dominate today. But I am hopeful that at some stage the technology will be licensed, and we can hope that one day we no longer suffer the inherent jitter in SPDIF and AES/EBU interfaces. That will make the server or transport much less relevant and we can then use what makes sense to us individually to manage our files, and the key issue becomes the DAC. In the meantime we have some tough choices and trade-offs, but I am already convinced that the CD transport has been beaten. Link to comment Share on other sites More sharing options...
Antipodes1553552706 Posted June 29, 2009 Share Posted June 29, 2009 nixon76;95350 wrote: Re the things that Antipodes talks about - esp Ethernet - you can find them here: http://www.positive-feedback.com/Issue41/ca_nugent.htm Yes, just paraphrasing what others are working on to answer the feckless question about ethernet. My interest is in which of the available solutions sounds best today and that has taken me into the world of understanding how to get the best out of each. Link to comment Share on other sites More sharing options...
kiwibrucie Posted June 30, 2009 Share Posted June 30, 2009 Hey Antipodes ......... long live your verbiage!! It's a damn sight more informative and thought provoking than most of the confusing , literally challenged (and altogether not succinct) short postings you see on a lot of these audio forums. Keep up the good work!! :-) Link to comment Share on other sites More sharing options...
Antipodes1553552706 Posted June 30, 2009 Share Posted June 30, 2009 The other alternative is to keep what I am doing secret and embed it in an expensive product to sell to you guys, but I thought it more fun to talk about it here. It is an interesting area that, I think, will change how we acquire and play music, and the quality of music reproduction, quite profoundly over the next decade. I had thought there might be a business in putting together something like the Cics player but my sense now is that one is for the DIY market, and the Transporter/Squeezebox is still the best off the shelf idea, with the Empirical stuff sitting in between if you want more flexibility and don't mind dedicating a PC or laptop to the task. Link to comment Share on other sites More sharing options...
kaka Posted June 30, 2009 Share Posted June 30, 2009 curious_george;95348 wrote: Have a look at the new PS Audio Perfect Wave DAC and Transport. Definitely some new thinking there. http://www.psaudio.com/ps/products/ Interested in your thoughts. Well, well. There is plenty of promise in the approaches in that DAC - I2S and the network bridge in particular. I wonder if the dac itself is a sonic winner, its time to do some searching for reviews. Thanks for the post Link to comment Share on other sites More sharing options...
nixon76 Posted June 30, 2009 Share Posted June 30, 2009 Just had a proper read and looked at the video - very nice - has a remote app for Ipod touch/phone as well. Link to comment Share on other sites More sharing options...
Antipodes1553552706 Posted June 30, 2009 Share Posted June 30, 2009 Now that's what I am talking about. Provided they are buffering the ethernet feed enough and clocking it out well, and I expect they are, then it ought to beat the I2S as while I2S does not have inherent jitter, you still need to transport it from one machine to another with all the timing data perfectly intact. The PS Audio dacs have been fairly good in the past so it could be very promising. I would want the six channel DAC model with DSP for tri-amping when they make one. Link to comment Share on other sites More sharing options...
NeilNZ Posted June 30, 2009 Share Posted June 30, 2009 It does look like an excellent well thought out product. If I was starting over, that would be on the shortlist no doubt. Link to comment Share on other sites More sharing options...
curiousgeorgenz Posted June 30, 2009 Share Posted June 30, 2009 Also check their newsletters for more commentary, http://www.psaudio.com/ps/newsletters/june-2009-ps-newsletter/ However at USD3000 it better be good...! Link to comment Share on other sites More sharing options...
nixon76 Posted June 30, 2009 Share Posted June 30, 2009 Pretty reasonable for what it is I reckon. If it had been out when I bought my BC I probably would have given it a go - it's a preamp as well after all. Link to comment Share on other sites More sharing options...
ilikecrumpets Posted June 30, 2009 Share Posted June 30, 2009 Elive has the Transporter on special for $2667.30 http://www.elive.co.nz/logitech-squeezebox-silver-transporter-t13212.php Oddly the black version is $130 dearer... Link to comment Share on other sites More sharing options...
NeilNZ Posted June 30, 2009 Share Posted June 30, 2009 Once you go black you never go back! Thats pretty weird though... Link to comment Share on other sites More sharing options...
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