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Hi I've ordered a Denon 1940 to use as a SACD transport- new, but at a bargain price- and a service manual. I intend to install a DSD output to feed my Buffalo II/Legato (and, possibly- I2S out too, but not straight away). I'm confident I can do this. But my knowledge of digital electronics and networking is slight, so I thought it best to check a few things first with the crowd in the know! I'm going to fit RJ45 output jacks, and CAT patch cables, as Mr Majestic described here- http://www.twistedpearau...t.aspx?g=posts&t=992 Should I just use CAT 5E, or use CAT 6 cable/connectors instead? Should I go for UTP, FTP, or STP cables (unscreened, overall screened, and individually screened twisted pairs respectively)? If I use a screened version, should I connect the screen just to the chassis ground of one component only (i.e. DAC and /or transport), or? Presumably I use one half of one twisted pair for each of D1, D2, and CLOCK (3 TP's in total), and connect all the other three halves to digital ground at each end? What should I do with the fourth TP- leave it floating, ground it or? Will I need to fit output buffers as described here? (I suspect not, from what I’ve gleaned from previous efforts) http://www.diyaudio.com/...40-dsd-ttl-level-out.jpgIf I do, will DIL package hex inverters be OK (rather than SOIC types)? Is a 0.5 m patch cable too long? Thanks in advance Paul Edited by user Thursday, January 27, 2011 2:11:23 AM(UTC)
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Simple twisted pairs is good enough. The shielding in CAT6 is for GHz speeds. You also have a GND line from Transport to DAC, so total of 4 wires (or 4 pairs if you shield each line -you could even use the 3 GND pairs as the GND line). You could tie all the GNDs in the pairs and connect them to one end only (say the transport -it probably wouldn't matter where to connect the GND, one side or both sides)
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Rank: Advanced Member
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Hi
Thanks glt. So I'll I think I'll use one wire of three of the twisted pairs,for D1, D2 and CLK respectively, leaving the fourth twisted pair unconnected. And connect the other wire of each pair to digital ground at the transport, and at the DAC, to provide screening and the GND conection. I'll use a FTP CAT 5e patch cable, and ground the overall screen to mains ground at one end only.
Anyone any other thoughts? I know several people have done this in the past. Would I be better using buffer amps for better drive? and/or to convert to a differntial signal out in the transport, and back to SE in the DAC? If so, how? Could I use transformers for this?
Would a better clock in the player be likely to be advantageous?
Thanks
Paul
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Hi Paul, It works fine without any buffering. I think DSD is already a differential signal. It also works nicely with I2S even if this in not a differential signal. I don't think there is any real standard for DSD/I2S on Cat5 cable but I have noticed that at least two commercial producers (North Star and Kingrex) use the same RJ45 wiring. You can of course wire as you want but it is very nice to be able to switch between different I2S/DSD sources without having to rewire the DAC. I'm currently listening to BII with a UC192 USB2->I2S converter that happily play the only real (i.e. not up-sampled) 32bit audio file I have been able to get my hands on :-) If you want differential data transmission and galvanic isolation you could get a set of these (post 1776) I2S/DSD over HDMI transmitter and receivers. These also carry I2C signal so the DAC can be controlled remotely. Recommended RJ45 wiring: 1) SCLK (brown) -> DCK on BII 3) DATA (blue) -> D1 on BII 5) LRCK (green) -> D2 on BII 7) MLCK (orange)-> not connected on BII 2, 4, 6 and 8 GND
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Rank: Advanced Member
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Joined: 7/22/2009(UTC) Posts: 81 Location: Norwich, UK Thanks: 2 times
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Hi Nic
Thanks for the reply. I made the mod last weekend, in the much way you describe, and it works very well. Just DSD for now.
I wonder now whether a clock upgrade in the Denon would be worthwhile? And some power supply improvements? And whether I should remove the three 47R resistors through which the data and clock signals enter the Denon's SACD DAC- so that the signals feeds only Buffalo
Thanks
Paul
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needsp wrote:...
I wonder now whether a clock upgrade in the Denon would be worthwhile? And some power supply improvements? And whether I should remove the three 47R resistors through which the data and clock signals enter the Denon's SACD DAC- so that the signals feeds only Buffalo
Thanks
Paul
That depends on how many SACD discs you have :-). People have starting to sell DSD downloads and you can use the Korg player to play/convert to 24/192K... Edited by user Saturday, February 12, 2011 11:31:25 AM(UTC)
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Rank: Advanced Member
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glt,
Is it possible to rip the DSD files from a SACD using the Korg player?
Thanks,
Nic
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Hi Nic,
No, you cannot. There is some info at audioasylum about using and old version PS3 to rip DSD out of SACDs, but those early version PS3 are hard to come by and you need to hack the firmware...
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The Korg player converts to PCM. Its is not playing native DSD. While very good, that is not exactly ideal.
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Rank: Advanced Member
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Russ, would you happen to know any alternative routes to get DSD to the Buffalo?
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