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another weird s/pdif unstability problem in BIII dac with sidecar and s/pdif pcb
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An alternative, if you have multiple Toslink inputs, is to use then direct to the dac, then use single spdif modules for the one or two coax inputs.
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That should work also, but then you get a very long= vulnerable connection to the DAC's Din. I think I experimented with that Idea, but did not succeed.
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Joined: 12/7/2011(UTC) Posts: 474 Location: Amsterdam
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Brian Donegan wrote:An alternative, if you have multiple Toslink inputs, is to use then direct to the dac, then use single spdif modules for the one or two coax inputs. Just like I trie to do now? I have just one Toslink Module which is interferring the COAX or better; the Toslink is distorded when the COAX is connected to the S/Pdis board. By connecting the Toslink direct to the DAC's and the rest via the S/Pdif board that problem is tackled. Somehow I do now have a locking problem with the COAX. That was'nt there before so I try a little further. I might use twisted pairs for the Toslink to the DAC's. Twisting the - of the pair together with the shielding this might provide sufficient shielding. Let's try
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Ok so I tried... I made a junction from the Toslink direct to the two DAC bords. Now I had a sync problem. Lifting one connector and re-attach it again made them line up... (again and again) Maybe the lines became too long? (appr. 12 cm?) When connecting the COAX cable to the S/Pdif board, no distortion was observed. So that is an improvement. But when playing via the COAX the locking signal was still unstable with the Toslink module connected directly to the DAC boards... I changed everything to my old configuration (only Toslink conn. to S/Pdif Mod.)and played whole evening until I sometimes heard a little Tick. It was the first time I played a CD i.s.o. music from the harddisc so I may encounter some Jitter problems when playing a CD... So we're not done jet! Monday I will go to the nearby store to get me some of those 75Ohm resistors and try it the way it was so successfull for Henri... I hope this will solve it because everything i becomming to wear out of all the different set-ups
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henri47 wrote:That should work also, but then you get a very long= vulnerable connection to the DAC's Din. I think I experimented with that Idea, but did not succeed. To make it work you would have to completely disconnect the SPDIF4 on the channel with TTL. That would mean cutting ribbon conductors.
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Joined: 12/7/2011(UTC) Posts: 474 Location: Amsterdam
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There is only a connection left from D1 of the S/Pdif board to the Sidecar via the Ribbon cables but not from the Sidecar to the DAC boards.
Will it still help to cut away the D1 line from the S/Pdif Board to the Sidecar?
I will try tomorrow...
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Hello Jordo, Sorry to hear it did'n work out for you. Since I installed the voltage divider, SPDIF and I2S are stable. Except SPDIF in the first minutes of warm-up. In these first minutes an occasional unlock can happen, but after that the sync is stable. I2S from my HD is always fully stable and unlocks never happen. I asked myself how far you can go in weakening the SPDIF TTL signal of the Toslink module without any problem for the 4*SPDIF. Would a voltage divider of say 560-1k/75 Ohm also work? I will try that on monday. The idea is attractive because the SPDIF signal is a lot weaker and interaction with other signals would likely be less. The 4*SPDIF board then again pumps it up to TTL level. Maybe Russ or Brian can tell us how far we can go weakening the SPDIF signal? Quote:To make it work you would have to completely disconnect the SPDIF4 on the channel with TTL. That would mean cutting ribbon conductors I admit not having completely disconnected the TTL channel . That could be the cause it did not work for me. I will try again next week. grts, Henri
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I wouldn't bother. The best idea is just to keep all of the inputs into the SPDIF4 at consumer SPDIF or AES levels. That is how it is designed to work. :) The voltage divider for the TOSLINK board does just that. :)
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Ok, will do that. Now I have to get some 75 Ohm resistors quick. :)
thx,
Jordo
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Well, I just made the cableconnection according the drawing above but I have no Lock of the signal this way. I have used 2 resistors (56 + 18 = 74 Ohm) in line connecting the Signal and ground and a 270 Ohm resistor in the signal line. I connected it to a 75 Ohm S/Pdif input on the S/Pdif board... If I meassure between the Signal and the ground I have a value of 275 Ohm.. Why isn't it working? Jordo attached the following image(s): spanningsdeler.png (9kb) downloaded 145 time(s). spanningsdeler2.png (33kb) downloaded 134 time(s).You cannot view/download attachments. Try to login or register.
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Joined: 12/7/2011(UTC) Posts: 474 Location: Amsterdam
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And again all kinds of Lock problems when playback trough the COAX and the Toslink only connected with no source...
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Here is how it has been done. Under the Shrink sleeve is the 270 Ohm resistor. Jordo attached the following image(s): Spanningsdeler real 2.jpg (144kb) downloaded 107 time(s). Spanningsdeler real.jpg (157kb) downloaded 102 time(s).You cannot view/download attachments. Try to login or register.
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Joined: 12/7/2011(UTC) Posts: 474 Location: Amsterdam
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So I tried an improved version. The good thing is that both the Toslink and the COAX are connected and I have the COAX playing without Unlocks. Less good is that the Toslink is still not working... Jordo attached the following image(s): Spanningsdeler real 3.jpg (147kb) downloaded 93 time(s).You cannot view/download attachments. Try to login or register.
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Hello Jordo, That's the right way to do it. I don't know why it does'nt work for you. On the other hand there are so many things we don't know and it is difficult to point at the reason for the trouble we have with the incoming signals. I must say it worked for me, but I had to set the DPLL switch to low medium or Medium to get a good lock. A second reason I had more success with the SPDIF inputs is maybe the fact I did not hook up a SPDIF-Coaxial signal. I do not have the need to do so because I have no source delivering Coaxial SPDIF. My mean source is music stored on my Vortexbox and it outputs USB2. But maybe I should install that coaxial input and see what happens. I hope someone here on the forum can help you. Kind regards, Henri
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Jordo, try just using ordinary hookup wire. Coax is not going to help you here.
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Joined: 12/7/2011(UTC) Posts: 474 Location: Amsterdam
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Well, I think my Toslink module doesn't like it anymore. I tried to hook it up the old way it used to work but it does'nt now....
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It could be that at some point the output of the TORX module was shorted, which could cause it to fail. Do you have a scope?
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jep, I'm affraid so....... I was so close to success damn!... No, sorry I have no scope. Is there another way to test the output? Can I meassure some or any current at all?
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I do meassure some milivoltages at the Toslink output in the order of 135mV but it degrades how longer I keep the meter on it...
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Joined: 12/7/2011(UTC) Posts: 474 Location: Amsterdam
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Never mind. I order a new one.
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another weird s/pdif unstability problem in BIII dac with sidecar and s/pdif pcb
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