[davidvanderbilt]

  What was the noise like?  Coming from headphones? (IEMS only or IEMS and bigger cans) Or line outs?  There when not connected to anything else?

 
It was a high-pitch frequency ringing noise coming from the R/L outputs using both optical and USB inputs. The sound was a lot more noticeable when connecting to my amp and speakers, but still there on my HD 600s.

 

[greenkiwi]

I don't have that with either of my DC-1s... only a high noise floor when trying to use them with IEMs.

 

[Zoom25]

I still have issues with left channel noise in Asynch mode with all the inputs. It goes away with Synch mode. I did make a complaint about it to Emotiva but after a while didn't bother with it. I'm just going to leave it there in synch mode and move on. If in future, this problem comes to synch mode as well, then I'll definitely get it looked at. I stopped caring about the asynch mode. Too much hassle to return and get another one and if it will work or not. Apparently a few people on Emotiva forums have the same problem as me.

 

[greenkiwi]

  I still have issues with left channel noise in Asynch mode with all the inputs. It goes away with Synch mode. I did make a complaint about it to Emotiva but after a while didn't bother with it. I'm just going to leave it there in synch mode and move on. If in future, this problem comes to synch mode as well, then I'll definitely get it looked at. I stopped caring about the asynch mode. Too much hassle to return and get another one and if it will work or not. Apparently a few people on Emotiva forums have the same problem as me.

If you do ever go to sell it, you can ship it back to Emo HQ and have them fix it and then ship it directly to the buyer.

 

[pressureworld]

I heard the DC-1 at "Emotiva on the Road"  this year in Atlanta and was really shocked at how much better it sounded from my XDA-1. I plan to pick one up, but I'm curious about using it with Beyer DT880 600's. Has anyone tried this combo?

 

[Somatic]

Bought the DC-1. No problems with the unit. I did have initial issues installing the driver on Win7 64bit but that was it. Remote and unit built like a tank.
 
I am using both an Emotiva Mini X amp in conjunction with the DC-1. Very smooth.
 
Much better than the Dragonfly I used to own.

 

[SharpEars]

I believe I have found the cause of the left channel buzz problem when using Asynchronous USB mode on the DC-1. It seems that if the playback device is set to any sample rate configuration other than 192 kHz, the buzz will be present. The higher the sample rate setting the less noticeable the buzz (e.g., 96 kHz almost no buzz, 44.1 kHz - very prominent buzz when playing audio material, regardless of its actual sample rate).
 
On Windows 7, you can use the following steps to change the sample rate and bit depth of the playback device:
 
1. Right click on the speaker icon in the system tray
2. Select playback devices from the menu
3. Right click on the device that matches the following description (this is the driver for the DC-1):
Speakers
USB2.0 High-Speed True HD Audio
4. Select Properties from the menu
5. On the Advanced Tab in the Default Format section, select the bit depth and sample rate you would like to experiment with.
6. You can use the Test button to the right of the sample rate/bit depth selection combo box to check for the left channel buzz.
7. Click on the OK button to confirm your selection.
 
If you choose any sample rate other than 192 kHz, there will most likely be a buzz present in the left channel. Please not that even when using Synchronous mode, you may have to manually set the sample rate to match the material being played if your player cannot do this for you (i.e., by using ASIO instead of MME and forcing the sample rate).
 
So, where does that leave us? Basically you have two options:
 
1. Use USB Synchronous mode (and possibly manually set the sample rate to match playback material for optimal fidelity, if your player cannot do this automatically)
2. Use USB Asynchronous mode with the sample rate set to 192 kHz, forcing up-conversion (This option makes asynchronous mode useless in my book).
 
I believe that the people who report not to be having any noise in their left channel when using USB Asynchronous mode, simply have their sample rate forced to 192 kHz in the playback device settings forcing up-conversion of all played material (and resulting in no buzz in their left channel).
 
I hope I have been of help...
 
P.S., I am uncertain if MACs or Linux are affected by this issue.

 

[Zoom25]

^ Cool, will try this out soon and report back if my left channel prob goes away.
 
EDIT: I'm on a Mac and this is a problem with every software, including Audirvana+

 

[skeptic]

If that is the fix for Windows, it is almost doubly frustrating because it is going to force you to run your audio through direct sound and the kmixer.  If you output via KS, wasapi, or asio, your player (foobar, etc.) will play the files at their native bitrate, and presumably the buzz will return.  Can you check on this sharpears?

 

[SharpEars]

It doesn't matter what player you use in Asynchronous mode. If you cannot force the bitrate to stick at 192 kHz (i.e., if your player sets it to something else in WASAPI/ASIO), you will get a left channel buzz with prominence dependent on the deviation amount from 192 kHz. This is either a bug in the C-Media USB2.0 driver (then why would MAC users [e.g., Zoom25] be affected?) or the hardware/firmware itself as far as I can tell (the far more likely scenario).
 
I would like for others to test my solutions (and reproduction of the problem) just to be certain that everyone is affected and just some users.

 

[KeithEmo]

Sorry I haven't been over this way in a while (and I seem to have misplaced my old username).....
 
Anyway.... I see some interesting conclusions on this thread - but, unfortunately, most of them aren't technically correct.
Therefore, I'd like to take this opportunity to clarify things.
 
You will NOT get "noise floor problems" because of a faulty driver. The driver simply passes the bits on from your player to the DAC. A bad driver, or a driver conflict, could potentially cause dropouts, loss of signal, and could even cause your computer to be unable to see the DAC at all, or to refuse to play at certain sample rates if the driver "says" it doesn't support them - but it isn't going to raise the noise floor - it simply doesn't work that way. (In those rare instances when a driver causes "screeching" or "popping" issues, those are actually symptoms of the signal dropping out for very short periods of time, and are not actually "distortion" introduced into the data itself.)
 
However, various hardware issues could possible cause the noise normally present on the ground of a computer to "bleed through" into the audio, and that noise (on the computer itself) will vary depending on what software is running (because that affects how much current the computer uses and the "patterns" that use follows). With a bad ground noise problem, you can sometimes actually hear the pitch of the noise change as you open or resize windows on the screen. Since Optical inputs are always isolated, and the Coax input on the DC-1 is also transformer isolated, this should only ever happen with USB (unless there's a hardware problem)... and, if your computer is really bad, a $50 USB ground isolator will eliminate it (but you really shouldn't need one).
 
1) The noise floor on the DC-1 is pretty low (check the specs for yourself), but still not low enough to be inaudible with some very sensitive IEMs. (It will work great with all regular headphones, and MOST IEMs, but wasn't specifically designed to be used with super-sensitive IEMs.)

 
2) Sometimes you will get ground noise issues due to the way the DC-1 and whatever component you have connected to it are grounded. If you think this might be happening, simply ground the outside shield from one of the DC-1's RCA connectors directly to a similar point on your source equipment; IF you have a ground noise problem, that should make it go away. If it doesn't go away, then you probably don't have ground noise.
 
3) However, IF you have a noise issue on your DC-1, with all types of inputs, and ONLY when the ASRC is enabled, and grounding your stuff together doesn't help, then you probably have a hardware issue with your DC-1 - and you should call or e-mail us (Emotiva) for an RMA so we can get it fixed for you. In general, switching the ASRC in and out, while NOT changing anything else, should NOT cause a huge jump in noise level and, if it does, then you probably have a hardware problem.

 

[SharpEars]

Hi Keith, just

  Sorry I haven't been over this way in a while (and I seem to have misplaced my old username).....
 
Anyway.... I see some interesting conclusions on this thread - but, unfortunately, most of them aren't technically correct.
Therefore, I'd like to take this opportunity to clarify things.
 
You will NOT get "noise floor problems" because of a faulty driver. The driver simply passes the bits on from your player to the DAC. A bad driver, or a driver conflict, could potentially cause dropouts, loss of signal, and could even cause your computer to be unable to see the DAC at all, or to refuse to play at certain sample rates if the driver "says" it doesn't support them - but it isn't going to raise the noise floor - it simply doesn't work that way. (In those rare instances when a driver causes "screeching" or "popping" issues, those are actually symptoms of the signal dropping out for very short periods of time, and are not actually "distortion" introduced into the data itself.)
 
However, various hardware issues could possible cause the noise normally present on the ground of a computer to "bleed through" into the audio, and that noise (on the computer itself) will vary depending on what software is running (because that affects how much current the computer uses and the "patterns" that use follows). With a bad ground noise problem, you can sometimes actually hear the pitch of the noise change as you open or resize windows on the screen. Since Optical inputs are always isolated, and the Coax input on the DC-1 is also transformer isolated, this should only ever happen with USB (unless there's a hardware problem)... and, if your computer is really bad, a $50 USB ground isolator will eliminate it (but you really shouldn't need one).
 
1) The noise floor on the DC-1 is pretty low (check the specs for yourself), but still not low enough to be inaudible with some very sensitive IEMs. (It will work great with all regular headphones, and MOST IEMs, but wasn't specifically designed to be used with super-sensitive IEMs.)
 
 
2) Sometimes you will get ground noise issues due to the way the DC-1 and whatever component you have connected to it are grounded. If you think this might be happening, simply ground the outside shield from one of the DC-1's RCA connectors directly to a similar point on your source equipment; IF you have a ground noise problem, that should make it go away. If it doesn't go away, then you probably don't have ground noise.
 
3) However, IF you have a noise issue on your DC-1, with all types of inputs, and ONLY when the ASRC is enabled, and grounding your stuff together doesn't help, then you probably have a hardware issue with your DC-1 - and you should call or e-mail us (Emotiva) for an RMA so we can get it fixed for you. In general, switching the ASRC in and out, while NOT changing anything else, should NOT cause a huge jump in noise level and, if it does, then you probably have a hardware problem.

 
Hi Keith, thank you for your comments and advice. In reference to your last item (#3).
 
1) The noise only appears when using the ASRC with no other changes to the system or environment.
2) The noise does not sound like conventional ground loop hum - it sounds more like a discrete digital stutter overlaid over the sound being played. I realize that we are in the digital domain, so this statement may not mean much. However, unlike constant ground loop hum, it is also correlated to the material being played (i.e., only present when there is sound present and a function of that sound, although it is not clear to me what that exact correlation is without much further testing). However, it is not correlated to mouse movement windows opening/closing, hard drives spinning or other computer activity as far as I can tell (I know exactly what you meant when you asked this, because many cheap sound cards do make various spurious sounds that seem to be related to computer activity and video changes.)
3) The noise is only present in the left channel (another indicator that this is not a grounding issue).
4) The amount of noise (i.e., it's amplitude) is a function of the deviation from the 192kHz sample rate (i.e., it is more audible at 44.1 kHz, far less audible at 96 kHz and completely absent at 192 kHz). This refers to the sample rate displayed on the unit, not the sample rate of the source material. There is no correlation between the source material sample rate and the actual "played at" sample rate with regard to this noise. In other words it is a function of the configured sample rate for MME or the WASAPI/ASIO negotiated rate (i.e., finally, the rate displayed on the Emotiva unit) and is independent of the source material's sample rate. To say it differently, you can play 44.1 kHz sampled material at a 44.1 kHz sample rate (i.e., no conversion) with ASRC and hear this noise quite prominently. Likewise with 48 kHz sampled material (as found in the audio material on many Blu-Ray discs) being played at a 48 kHz sample rate as displayed on the unit.
5) It is a problem not with one unit or five units, but either all units or many units (Note: This statement is somewhat anecdotal and based on reading the forum posts of other users affected by this issue).
6) It is independent of the player being used. In fact it can be reproduced with no player at all, but by simply pressing the play button next to the sample rate selection combo box of the Windows playback device settings dialog - see my original post on how to reproduce the problem easily and consistently.
7) The noise is definitely present when the balanced line outs are used, which is how I use the unit. It is most likely present in the headphone output as well, based on other forum posts, but I have not verified).
8) It is not clear if this problem is caused by incompatibility with certain USB chipsets, affects only some units or affects all units at this time, you guys will have to do internal testing to figure that one out.
 
I would be very thankful if others would follow my steps as posted in a previous post for reproducing this problem and report back if they cannot reproduce it with their unit, so that we can at least know that it is a problem only affecting some units/users/USB chipsets, but not all. If I can narrow things down further, I will update this post to help with troubleshooting.

 

[elwappo99]

  Sorry I haven't been over this way in a while (and I seem to have misplaced my old username).....
 
Anyway.... I see some interesting conclusions on this thread - but, unfortunately, most of them aren't technically correct.
Therefore, I'd like to take this opportunity to clarify things.
 
You will NOT get "noise floor problems" because of a faulty driver. The driver simply passes the bits on from your player to the DAC. A bad driver, or a driver conflict, could potentially cause dropouts, loss of signal, and could even cause your computer to be unable to see the DAC at all, or to refuse to play at certain sample rates if the driver "says" it doesn't support them - but it isn't going to raise the noise floor - it simply doesn't work that way. (In those rare instances when a driver causes "screeching" or "popping" issues, those are actually symptoms of the signal dropping out for very short periods of time, and are not actually "distortion" introduced into the data itself.)
 
However, various hardware issues could possible cause the noise normally present on the ground of a computer to "bleed through" into the audio, and that noise (on the computer itself) will vary depending on what software is running (because that affects how much current the computer uses and the "patterns" that use follows). With a bad ground noise problem, you can sometimes actually hear the pitch of the noise change as you open or resize windows on the screen. Since Optical inputs are always isolated, and the Coax input on the DC-1 is also transformer isolated, this should only ever happen with USB (unless there's a hardware problem)... and, if your computer is really bad, a $50 USB ground isolator will eliminate it (but you really shouldn't need one).
 
1) The noise floor on the DC-1 is pretty low (check the specs for yourself), but still not low enough to be inaudible with some very sensitive IEMs. (It will work great with all regular headphones, and MOST IEMs, but wasn't specifically designed to be used with super-sensitive IEMs.)
 
 
2) Sometimes you will get ground noise issues due to the way the DC-1 and whatever component you have connected to it are grounded. If you think this might be happening, simply ground the outside shield from one of the DC-1's RCA connectors directly to a similar point on your source equipment; IF you have a ground noise problem, that should make it go away. If it doesn't go away, then you probably don't have ground noise.
 
3) However, IF you have a noise issue on your DC-1, with all types of inputs, and ONLY when the ASRC is enabled, and grounding your stuff together doesn't help, then you probably have a hardware issue with your DC-1 - and you should call or e-mail us (Emotiva) for an RMA so we can get it fixed for you. In general, switching the ASRC in and out, while NOT changing anything else, should NOT cause a huge jump in noise level and, if it does, then you probably have a hardware problem.

 
Hey Keith just wanted to say thanks for stopping in and clarifying things. 
 
 
 
Been loving mine. I use my DC-1 on my daily computer rig and put a good 8 hours a day on it. It's such a simple device with so many good features in it. For example, I've got the XLR out running to my Airmotiv 4s which I always struggled to find a way to get volume control for. 
 
Also still have my A-100 hooked up to my main rig 

 

[boatheelmusic]

Thanks for your thoughtful response, Keith.

No problems at all using balanced outs on my highly resolving system.

 

[KeithEmo]

Just to be perfectly clear.... I work for Emotiva, so you can consider this to be "an official answer".....
 
We've sold lots of DC-1's, and the vast majority of customers have NOT had any problems with them... (so this is NOT "a problem with all or many units").
 
We've encountered "noise problems" with DC-1's for two reasons.
 
First, we've had two or three units which have had what we consider to be "ground related problems".
 
ALL computers have horribly noisy ground and power supply buses (it's just the penalty for switching amps of current at various high frequencies). You hear this noise on cheap sound cards because they don't take sufficient care to filter it out and shield against it, so it finds its way into the analog circuitry. The noise we're talking about is usually a sort of low level "chittering" noise, which may or may not be obviously related to what the computer is doing. Since a normal USB connection directly connects the ground and +5v buses from the source to the DAC, this noise can also find it's way into an external DAC. I've seen this happen a lot with USB-powered little DACs, but it rarely happens with DACs which run off line-powered supplies. When it does happen, it can always be eliminated by fully isolating the DAC (the Coax and Optical inputs of the DC-1 are galvanically isolated, but the USB input is not.) In one case where we had what we considered to be "ground related noise", we had the customer tie the DC-1's ground to the ground on his other equipment and the noise went away - which we took to confirm our diagnosis. In another, the unit was returned, and we were totally unable to replicate the problem. (We take that to suggest that his computer was especially noisy, and the DC-1 was sensitive enough to have a problem with it.)
 
In a few other instances, we had exactly the problem you reported - unusual noises or distortion, clearly correlated with what was playing, only or predominantly in one channel, and only when the ASRC was enabled. (The noises were also exactly the same with different types of inputs.) In both cases that I am aware of in detail, the problem turned out to be a hardware problem with the particular DC-1 unit. I'm pretty sure this is what's happening with yours....
 
However, as I said, this has only happened with two or three units that I am aware of - so it is not at all common. (However, if you're having the problem, you should call or e-mail support so we can arrange for an RMA so we can fix it.)
 
Keith
 
 
Quote:

  Hi Keith, just
 
Hi Keith, thank you for your comments and advice. In reference to your last item (#3).
 
1) The noise only appears when using the ASRC with no other changes to the system or environment.
2) The noise does not sound like conventional ground loop hum - it sounds more like a discrete digital stutter overlaid over the sound being played. I realize that we are in the digital domain, so this statement may not mean much. However, unlike constant ground loop hum, it is also correlated to the material being played (i.e., only present when there is sound present and a function of that sound, although it is not clear to me what that exact correlation is without much further testing). However, it is not correlated to mouse movement windows opening/closing, hard drives spinning or other computer activity as far as I can tell (I know exactly what you meant when you asked this, because many cheap sound cards do make various spurious sounds that seem to be related to computer activity and video changes.)
3) The noise is only present in the left channel (another indicator that this is not a grounding issue).
4) The amount of noise (i.e., it's amplitude) is a function of the deviation from the 192kHz sample rate (i.e., it is more audible at 44.1 kHz, far less audible at 96 kHz and completely absent at 192 kHz). This refers to the sample rate displayed on the unit, not the sample rate of the source material. There is no correlation between the source material sample rate and the actual "played at" sample rate with regard to this noise. In other words it is a function of the configured sample rate for MME or the WASAPI/ASIO negotiated rate (i.e., finally, the rate displayed on the Emotiva unit) and is independent of the source material's sample rate. To say it differently, you can play 44.1 kHz sampled material at a 44.1 kHz sample rate (i.e., no conversion) with ASRC and hear this noise quite prominently. Likewise with 48 kHz sampled material (as found in the audio material on many Blu-Ray discs) being played at a 48 kHz sample rate as displayed on the unit.
5) It is a problem not with one unit or five units, but either all units or many units (Note: This statement is somewhat anecdotal and based on reading the forum posts of other users affected by this issue).
6) It is independent of the player being used. In fact it can be reproduced with no player at all, but by simply pressing the play button next to the sample rate selection combo box of the Windows playback device settings dialog - see my original post on how to reproduce the problem easily and consistently.
7) The noise is definitely present when the balanced line outs are used, which is how I use the unit. It is most likely present in the headphone output as well, based on other forum posts, but I have not verified).
8) It is not clear if this problem is caused by incompatibility with certain USB chipsets, affects only some units or affects all units at this time, you guys will have to do internal testing to figure that one out.
 
I would be very thankful if others would follow my steps as posted in a previous post for reproducing this problem and report back if they cannot reproduce it with their unit, so that we can at least know that it is a problem only affecting some units/users/USB chipsets, but not all. If I can narrow things down further, I will update this post to help with troubleshooting.