My current connection between my Marantz cd5400 CD player (SPDIF out) and my Burrbrown PCM1794 DIY DAC (SPDIF in) uses a RG6 coaxial cable with ferrite beads on both ends. Is it a good or a bad idea to have ferrite beads on the cable sound quality wise. Looking for suggestions / advise.
Thanks in advance.
Thanks in advance.
OK, Thanks for clarifying. Will there be any degradation of the signal if there are ferrite beads on either end of the cable. I have seen people mentioning rolled off highs in the signal having ferrite beads hence thought of confirming once again. This again being a digital signal was wondering how it can be.
The actual SPDIF signal is at a sufficiently high frequency that it will be inside the cable, so it cannot see the ferrite on the outside. The ferrite might reduce RF pickup, or it might make no difference. One thing it certainly cannot do is affect the audio HF rolloff.
Maybe clean up the ground, since the shield would be getting the effect of the ferrite?
Not sure how that would effect the tonal balance, however.
Not sure how that would effect the tonal balance, however.
Only currents on the outside of the shield are affected by the ferrite, and they are just attenuated. Currents on the inside of the shield are confined there by skin effect, so they never make it to the outside where the ferrite is. Even if the ferrite could affect the SPDIF it could have no effect on tonal balance because a SPDIF signal is digital not analog. Just a bunch of numbers something like streaming music over an internet connection. It works or it doesn't, there can be no effect on tone. It would take some kind of DSP like a digital EQ to affect tonal balance. Ferrite just can't do digital mathematical calculations.
The main reason for using SPDIF rather than TOSLINK is that SPDIF can work up to 24/192, but TOSLINK is limited to no more than 24/96. However, TOSLINK being optical has no problems with ground loops or antenna effects, etc.
The main reason for using SPDIF rather than TOSLINK is that SPDIF can work up to 24/192, but TOSLINK is limited to no more than 24/96. However, TOSLINK being optical has no problems with ground loops or antenna effects, etc.
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Any 'rolled off highs' won't be due to the ferrite altering the digital signal. They'll be because the ferrite attenuates common-mode currents and those CM currents make their way into the audio system, causing intermodulation distortion. The absence of such IMD might sound like 'rolled off highs' but in reality its reduced colouration.
Digital signals are not infallible, obviously. They just don't behave exactly like analog signals when it comes to what they sound like after being altered somewhat in amplitude or otherwise distorted or modified by whatever means. Human brain is not infallible either, including in terms of what people may sometimes think they hear when their eyes see a piece of ferrite. I don't laugh at them when that happens though.
By the way, a piece of ferrite on a cable carrying an analog audio signal can affect sound very differently than if the signal were digital.
If isn't a matter of infallibility or a matter of whether there can be any effect or no effect. It is a matter of how information encoded in different ways can be affected by different kinds of alteration of a signal carrying that information.
In addition, obviously, at some level a digital signal is analog. And it may be that at some even lower level an analog signal is digital. We usually don't have to get down into such low level models, but we can if we need to. Not worth the bother if people have already made up their minds they are going to reject anything that is said.
By the way, a piece of ferrite on a cable carrying an analog audio signal can affect sound very differently than if the signal were digital.
If isn't a matter of infallibility or a matter of whether there can be any effect or no effect. It is a matter of how information encoded in different ways can be affected by different kinds of alteration of a signal carrying that information.
In addition, obviously, at some level a digital signal is analog. And it may be that at some even lower level an analog signal is digital. We usually don't have to get down into such low level models, but we can if we need to. Not worth the bother if people have already made up their minds they are going to reject anything that is said.
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A big thanks to everyone for their replies on the ferrite beaded coaxial cables. Since the ferrites wont be negatively affecting my digital signal, i will retain the same cable instead of going for a mod.
Thanks to all once again.
Thanks to all once again.
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SPDIF
SPDIF, both coaxial and optical, has a particular characteristic. They are "two-way." They are digital and analog. Audio data is digitally encoded, but the clock for its sampling is done in analog form at the preamble. From that viewpoint, the short cable(30cm) is better than long one(5m). I have tested short optical cables and long one before. Short one has better jitter performance than a long one at the output of TOSLINK receiver. But the CS8416 has excellent clock recovery ability to eliminate such difference between cables. I couldn't find distinguishable results both at the clock output of the CS8416 and the analog output of my DAC. My conclusion is that there is the difference of jitter between optical cables but no degradation in numbers of DAC output. SQ depends on personal likeness. It's beyond my measurement.
SPDIF, both coaxial and optical, has a particular characteristic. They are "two-way." They are digital and analog. Audio data is digitally encoded, but the clock for its sampling is done in analog form at the preamble. From that viewpoint, the short cable(30cm) is better than long one(5m). I have tested short optical cables and long one before. Short one has better jitter performance than a long one at the output of TOSLINK receiver. But the CS8416 has excellent clock recovery ability to eliminate such difference between cables. I couldn't find distinguishable results both at the clock output of the CS8416 and the analog output of my DAC. My conclusion is that there is the difference of jitter between optical cables but no degradation in numbers of DAC output. SQ depends on personal likeness. It's beyond my measurement.
Agreed about clock jitter. It gets worse in most any situation where it can, and it usually can in long cables. SPDIF, TOSLINK, I2S, PCM, AES, from one side of a PCB to the other, etc., are all places where jitter can get worse.
At least the digital part of SPDIF, as you describe it, allows us to reclock the analog part. Unless the signal is severely distorted, all the digitally encoded data we need is still there, and we know what we need to do to get it cleaned up and restored to like-new condition or maybe even with less jitter than it started out with.
At least the digital part of SPDIF, as you describe it, allows us to reclock the analog part. Unless the signal is severely distorted, all the digitally encoded data we need is still there, and we know what we need to do to get it cleaned up and restored to like-new condition or maybe even with less jitter than it started out with.
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