luvdunhill Posted April 21, 2010 Report Share Posted April 21, 2010 think about it. if the AES/EBU connection sounds vastly different to the other digital connections, something is badly broken. I disagree. One could have a properly terminated AES/EBU connection and horrible coaxial/toslink implementation. For argument's sake, the coaxial connector could have an incorrectly populated voltage divider resistor on the output. Would this be noticeable? yes. Quote Link to comment Share on other sites More sharing options...
luvdunhill Posted April 21, 2010 Report Share Posted April 21, 2010 badly broken. badly engineered Quote Link to comment Share on other sites More sharing options...
morphsci Posted April 21, 2010 Report Share Posted April 21, 2010 tomato/jamato Quote Link to comment Share on other sites More sharing options...
Voltron Posted April 21, 2010 Report Share Posted April 21, 2010 That's a slur to all tomatoes. Quote Link to comment Share on other sites More sharing options...
morphsci Posted April 21, 2010 Report Share Posted April 21, 2010 Agreed. I'll have to watch my back on the walk home. Quote Link to comment Share on other sites More sharing options...
Grahame Posted April 21, 2010 Report Share Posted April 21, 2010 Beware! Attack of the Killer Tomatoes - Wikipedia, the free encyclopedia Quote Link to comment Share on other sites More sharing options...
luvdunhill Posted April 21, 2010 Report Share Posted April 21, 2010 sorta reminds me of this book: http://www.amazon.com/exec/obidos/ASIN/0439104319/$%7B0%7D Quote Link to comment Share on other sites More sharing options...
spritzer Posted April 21, 2010 Report Share Posted April 21, 2010 Wasn't there some talk about the XLR connector being a very bad choice for the AES/EBU standard and only chosen since it was readily available? Quote Link to comment Share on other sites More sharing options...
cetoole Posted April 21, 2010 Report Share Posted April 21, 2010 Yes Quote Link to comment Share on other sites More sharing options...
spritzer Posted April 21, 2010 Report Share Posted April 21, 2010 Try to pronounce it.... In all seriousness the connector used does matter in the same way a RCA plug isn't an ideal choice for the 75ohm of the S/PDIF coax. The BNC is actually 75ohm but for some strange reason many of the "audiophile" connectors are the 50ohm variety. Quote Link to comment Share on other sites More sharing options...
Pars Posted April 21, 2010 Report Share Posted April 21, 2010 50 ohm BNC are used on scopes, etc. and seem to be more prevalent. Identified by more material around the center on chassis jacks. 75 ohm have next to nothing around the center. The XLRs used for AES/EBU are actually ~110 ohm (which is the standard), but are horrible for RF connections (i.e., S/PDIF or AES/EBU). Quote Link to comment Share on other sites More sharing options...
cetoole Posted April 21, 2010 Report Share Posted April 21, 2010 Try to pronounce it.... In all seriousness the connector used does matter in the same way a RCA plug isn't an ideal choice for the 75ohm of the S/PDIF coax. The BNC is actually 75ohm but for some strange reason many of the "audiophile" connectors are the 50ohm variety. XLR is 110ohm, which meets the spec for AES/EBU, it is that the connector has issues with RF signals, which is why they had to crank the voltage so high, which causes other issues... Bah, beaten by Chris. Quote Link to comment Share on other sites More sharing options...
Grahame Posted April 21, 2010 Report Share Posted April 21, 2010 This keeps coming up on the slim devices forum. Anyway I see two main reasons for the inferiority of AES/EBU. 1. XLRs are horrible RF connectors. In order to send a square wave fairly faithfully the interface must support a bandwidth many times higher than the frequency of the square wave. For the signals in question that is getting well up into the RF spectrum where the XLRs are terrible. The impedance varies radically with frequency which will cause all kinds of bizarre reflections. The choice of XLR was a very poor choice. 2. Output voltage. The S/PDIF electrical spec is 0.5V into 75ohms, but the AES/EBU is 3-5V into 110 ohms. Think about that for a second, what happens when you put 5volts across 110 ohms? You get almost 50mA of current flowing. This means the driver sitting in the source box has to be able to dump between 30-50ma into the cable. That causes huge current spikes in the power and ground pins of the driver chip which is going to cause big noise spikes in the power and ground planes of the board. If you are not extremely careful that is going to cause significant jitter in the output signal. All modern high speed interfaces use less than 0.5V signal. As far as I can tell the XLRs were chosen because studios had lots of microphone cables and wanted to use them. Because they are such lousy RF transmission lines they had to go with high voltages to make sure there was some signal left at the end. Maybe Tyll can tell us whats in this paper? AES E-Library: Is the AES/EBU/SPDIF Digital Audio Interface Flawed? Quote Link to comment Share on other sites More sharing options...
luvdunhill Posted April 21, 2010 Report Share Posted April 21, 2010 in systems that aren't broken/really badly engineered, are going to give any kind of meaningful difference. fair enough. my point is that most are badly engineered, hence the prevalent statement that one is better than another*. By badly engineered I mean not designed by a RF engineer. * I don't believe this 100%, who am I kidding. People hear what they want to hear. Quote Link to comment Share on other sites More sharing options...
luvdunhill Posted April 21, 2010 Report Share Posted April 21, 2010 what if they are designed by a mediocre RF engineer? I'd say it would be indistinguishable. Even better is if said mediocre engineer designed both pieces of gear that are being connected. Quote Link to comment Share on other sites More sharing options...
spritzer Posted April 21, 2010 Report Share Posted April 21, 2010 eggi.... eayja.... iegau... volcano. everything is a compromise. i'm highly doubtful that any of these compromises, in systems that aren't broken/really badly engineered, are going to give any kind of meaningful difference. meaningful being audible to human beings on any kind of consistent or predictable basis. Nope, how about "Island mountains glacier" since that's what it means in a direct translation? There are always compromises and to be honest, how many commercial pieces out there are well engineered from start to finish? There is always something rotten, somewhere... This keeps coming up on the slim devices forum. Anyway I see two main reasons for the inferiority of AES/EBU. 1. XLRs are horrible RF connectors. In order to send a square wave fairly faithfully the interface must support a bandwidth many times higher than the frequency of the square wave. For the signals in question that is getting well up into the RF spectrum where the XLRs are terrible. The impedance varies radically with frequency which will cause all kinds of bizarre reflections. The choice of XLR was a very poor choice. 2. Output voltage. The S/PDIF electrical spec is 0.5V into 75ohms, but the AES/EBU is 3-5V into 110 ohms. Think about that for a second, what happens when you put 5volts across 110 ohms? You get almost 50mA of current flowing. This means the driver sitting in the source box has to be able to dump between 30-50ma into the cable. That causes huge current spikes in the power and ground pins of the driver chip which is going to cause big noise spikes in the power and ground planes of the board. If you are not extremely careful that is going to cause significant jitter in the output signal. All modern high speed interfaces use less than 0.5V signal. As far as I can tell the XLRs were chosen because studios had lots of microphone cables and wanted to use them. Because they are such lousy RF transmission lines they had to go with high voltages to make sure there was some signal left at the end. Maybe Tyll can tell us whats in this paper? AES E-Library: Is the AES/EBU/SPDIF Digital Audio Interface Flawed? That's exactly what my mind was struggling to remember. Quote Link to comment Share on other sites More sharing options...
dimitris Posted April 21, 2010 Report Share Posted April 21, 2010 The D70 definitely has improved a lot the bass. I don't need the Rel Storm with the Cremona Auditors especially at medium and low levels. Quote Link to comment Share on other sites More sharing options...
Duggeh Posted April 21, 2010 Report Share Posted April 21, 2010 The 50-Ohm BNC cables/conectors are the kind used in old computer networking too aren't they? Quote Link to comment Share on other sites More sharing options...
Pars Posted April 21, 2010 Report Share Posted April 21, 2010 ^ 10-Base2 or thinnet used them. Quote Link to comment Share on other sites More sharing options...
Grahame Posted April 21, 2010 Report Share Posted April 21, 2010 Don't forget the terminator! 10BASE2 - Wikipedia, the free encyclopedia Quote Link to comment Share on other sites More sharing options...
spritzer Posted April 22, 2010 Report Share Posted April 22, 2010 I have fond memories of disconnecting those nice T-plugs at school and watch the whole network come crashing down. Quote Link to comment Share on other sites More sharing options...
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