Hi,
I have just purchased a second-hand NAD C541i CD player. Everything works but i seem to have a problem with the Co-axial Digital output. On loading a new disc and spin-up to read the TOC, the Coaxial output signal is a very high level crackling noise which could damage my speakers. The Line outputs are OK, they are muted properly. Is this a known NAD C541i
design fault or is my player faulty. I have looked at the service manual and it appears that there is no way the circuit will mute the disc reading the TOC on spin-up. Any ideas?
I have just purchased a second-hand NAD C541i CD player. Everything works but i seem to have a problem with the Co-axial Digital output. On loading a new disc and spin-up to read the TOC, the Coaxial output signal is a very high level crackling noise which could damage my speakers. The Line outputs are OK, they are muted properly. Is this a known NAD C541i
design fault or is my player faulty. I have looked at the service manual and it appears that there is no way the circuit will mute the disc reading the TOC on spin-up. Any ideas?
I'm not familiar with the NAD at all, however...
What are you feeding the Digital output into ? I'm assuming a DAC but had to ask 🙂
Are you saying it plays OK apart from noise reading TOC when using digital feed only.
Could it be a external DAC issue ? Sometimes crackling can occur if the clock frequencies are slightly out. The only way to prove that is perhaps with another DAC.
Also some DAC's use different levels,
http://www.diyaudio.com/forums/digi...dian-500-transport-arcam-bb2.html#post2386313
What are you feeding the Digital output into ? I'm assuming a DAC but had to ask 🙂
Are you saying it plays OK apart from noise reading TOC when using digital feed only.
Could it be a external DAC issue ? Sometimes crackling can occur if the clock frequencies are slightly out. The only way to prove that is perhaps with another DAC.
Also some DAC's use different levels,
http://www.diyaudio.com/forums/digi...dian-500-transport-arcam-bb2.html#post2386313
Mooly, thanks for your quick response!
I am feeding the Co-axial Digital Output into a Mission DAC5 Full Differential Bitstream Converter. Previously, i was using this DAC with an Alpha 7SE CD Player (circa 2000) with no problems. To be honest, i did
not consider it to be a DAC issue so thanks for pointing this out. I have
looked at the circuit diagram and the Line outputs have a MUTE circuit
which is working. Looking at the Digital Coaxial/Optical circuit there is no
MUTE so unless the TOC data read on spin-up is muted somewhere else,
it does tend to point to the DAC and a possible clock incompatability.
I guess the obvious question is to ask anyone using a NAD C541i CD Player with an external DAC (brand?) if they have had any problems. The Mission DAC must be at least 10 years old!
I am feeding the Co-axial Digital Output into a Mission DAC5 Full Differential Bitstream Converter. Previously, i was using this DAC with an Alpha 7SE CD Player (circa 2000) with no problems. To be honest, i did
not consider it to be a DAC issue so thanks for pointing this out. I have
looked at the circuit diagram and the Line outputs have a MUTE circuit
which is working. Looking at the Digital Coaxial/Optical circuit there is no
MUTE so unless the TOC data read on spin-up is muted somewhere else,
it does tend to point to the DAC and a possible clock incompatability.
I guess the obvious question is to ask anyone using a NAD C541i CD Player with an external DAC (brand?) if they have had any problems. The Mission DAC must be at least 10 years old!
I think you would find that if you disabled the analogue line mute that the noise reading the TOC still would not be present via line out.
Trying to think how all this works 🙂
I see the NAD has an optical output. Have you tried that into anything ? TV, AV receiver, Minidisc. It is the same signal as the coax feed.
I know if you take an SPDIF optical feed and hold the plug away from either the transmitter or receiever so the "light" or signal level is low then the typical symptom is a harsh crackling noise. And that can change when music comes along. The data from the SPDIF output is continous. There is no "mute" or interuption of data. All the info the DAC needs to know is in the data stream.
It's 50/50 whether it's the NAD or DAC
Do try and check in any manuals etc exactly what the spec is for the coax SPDIF feed and for the DAC input. As I mentioned before there are two levels in existance. Could it be on the very edge of working with the wrong level ? Just guessing on that but you need to be sure.
Trying to think how all this works 🙂
I see the NAD has an optical output. Have you tried that into anything ? TV, AV receiver, Minidisc. It is the same signal as the coax feed.
I know if you take an SPDIF optical feed and hold the plug away from either the transmitter or receiever so the "light" or signal level is low then the typical symptom is a harsh crackling noise. And that can change when music comes along. The data from the SPDIF output is continous. There is no "mute" or interuption of data. All the info the DAC needs to know is in the data stream.
It's 50/50 whether it's the NAD or DAC
Do try and check in any manuals etc exactly what the spec is for the coax SPDIF feed and for the DAC input. As I mentioned before there are two levels in existance. Could it be on the very edge of working with the wrong level ? Just guessing on that but you need to be sure.
Hi Mooly,
I think you are definitely on to something here. I cant believe the crackling noise problem on CD spin-up can be a design fault or otherwise.
It sounds like an incompatibility between the DAC5 and the Nad C541i. It just so happens that i have an old Dad5 CD player (cant stop collecting audio gear!) and it is meant to partner the DAC5 perfectly. If i hook these
up as a pair and there is no crackling noise then it points to the NAD C541i
as being the problem. Will report back on this forum so others can learn from this discovery. Thanks for your very informed help so far.
I think you are definitely on to something here. I cant believe the crackling noise problem on CD spin-up can be a design fault or otherwise.
It sounds like an incompatibility between the DAC5 and the Nad C541i. It just so happens that i have an old Dad5 CD player (cant stop collecting audio gear!) and it is meant to partner the DAC5 perfectly. If i hook these
up as a pair and there is no crackling noise then it points to the NAD C541i
as being the problem. Will report back on this forum so others can learn from this discovery. Thanks for your very informed help so far.
Second hand, huh? The mechanism is not good (long spindle shaft etc). Have a professional to check the optic and spindle servo and tune up the eye-pattern (if you don't have an oscilloscope), you may need that. Who knows the problem originated there.
I believe I may be experiencing the same thing with different equipment. I recently received an audio gd NFB 12.1 head amp/dac, and I get a loud burst or crackle when a cd player is hooked up with it. I have tried with 2 players, 1993 Philips 910 and a 2002 Marantz CC4000 ose. I have tried multiple cables. The sound occurs when the play button is pressed or when the multidisc Marantz shifts discs. The burst can be very short and clipped or up to a second or so with some diminishment.
Kingwa at audio gd thinks in might be that the cd players are not putting out a full .5V.
If it is the same thing it can't be that uncommon and I will continue a web search to track this down. I'll let you know if I find something, and monitor this post as well...
Kingwa at audio gd thinks in might be that the cd players are not putting out a full .5V.
If it is the same thing it can't be that uncommon and I will continue a web search to track this down. I'll let you know if I find something, and monitor this post as well...
I would have to call that a major sign of defective dac design, or just plain defective unit. No dac should do this with two different players. The statement about not putting out a full .5v is rubbish.
I'm leaning toward defective unit since Kingwa has apparently used the model with his variety of older CD players and not experienced any noise. The joys of ordering from far away...
Thanks.
Thanks.
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