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post #931 of 956

See Inline, I hope this works, cause I hate this new Forum Interface.
 


Les_Garten,

 

I apologize for confusing you with my previous posts. I will attempt to address your questions as systematically and thoroughly as possible in the hope that we might be able to determine the nature of the issue I am having with the Compass (Audio-GD is not replying to me anymore).

 

You keep saying that, and it appears you are trying to bring pressure to bear here.

 

I understand an iPod can't power full size headphones well, or really at all. I also understand IEM's are designed for a low output device like an iPod and do not need much to drive them. When I use the Compass to drive the IEM's I leave the VOLUME control at about 8:30 (if you were looking at a clock). I compared the Compass to the iPod and computer because both are not high end audio equipment and both do a better job reproducing music with the SE420's. The Compass, in my mind, should not produce any humming or buzzing no matter what headphones are used, if they are used at listening volume.

 

Not true, he can't make them work with everything.  Humming can be a sign of being overdriven.  Not saying that's for sure, but you're using a big piece of Hardware to drive IEM's.

 

You are correct that I did not buy a new Compass two weeks ago. I am fairly certain the model was discontinued a few months back. I paid for my compass March 30th, 2009. It probably arrived a few weeks later.

 

When the Compass arrived I used it almost exclusively with my AKG K701 headphones. The Compass was always set to the lower of the gain options. I could never get the optical setting to work with the Compass, so I use the USB from my computer to deliver the digital signal.

 

So, it worked fine one minute, you started using the IEMs and they buzz.  Doesn't matter that they don't buzz with a POS iPod opamp.  The real interest here is how they do with your 701s when you get them back working.  As far as the optical not working.  Don't take this the wrong way, but most people don't know how to switch the output of their soundcards.  I've been sent a number of pieces of gear that the optical was austensibly not working and it was a Windows Control panel issue or a SC software issue with being able to switch the output.  Not saying that is what is going, just something to consider.

 

Here's an important part. I believe I used the SE420 IEMs with the compass at some point. I do not remember hearing the buzzing I hear now, though I might have just never noticed it since music drowns it out at normal listening volumes. I am to uncertain to say whether I heard it or not.

 

That of course would be an interesting fact to KNOW.

 

As I state before, I had to send in the balanced to 1/4th inch connector I use with my balanced 701s, and thus, have been using the SE420 IEM's with the compass for the past nearly three weeks. I noticed the buzzing the first time I listened to music with the Compass.

 

You noticed it the first time you used it with the IEMs, not the 701s ever, Correct?

 

Allow me to clarify what the buzzing sounds like. The buzzing noise is just that, buzzing (or maybe a hum, I really don't understand there to be a difference between the two). Not static, not hissing, not noise. It is a buzzing that sounds like a medium frequency sound at a constant pitch. It is not piercing or low, but in the medium range of noises. It sounds like there may be an emphasis on the left channel of audio, but both channels have some buzzing. It is difficult to determine if one is louder than the other.

 

Does this noise only occur at high volume? NO. As I have tried to explain before it occurs at ALL volumes, regardless of the gain setting and regardless of whether the VOLUME is turned up. It does appear to become slightly amplified when the volume is turned up, but never rises above an annoying whisper (still clearly audible, but not amplified like music).

 

You might want to look over any wire connection in the box and see if any wire looks loose or a cracked solder joint.

 

The Bose headphones I used I can't really tell you much about. They were just over the ear Bose nonsense that my roommate uses.  What I can tell you is that when I cranked the gain or volume or whatever it is called, the Bose produced a nice static hiss. The same static hiss you get with all headphones when the gain is increased. The Bose headphones raised the noise floor much higher than the K701's at the Compass's maximum volume however. They also raised the noise floor higher than the SE420's at the Compass's maximum volume. The Bose did not however reproduce the buzzing of the SE420's.

 

So, the bose don't buzz and the 701s don't buzz, n'est-ce pas?  The place where hiss/noise occurs on a set of headphones will change with each set of different phones you use.  Has to do with the impedance and sesnsitivity.

 

I also used a no-name cheap pair of Sony earbuds I listen to when I go to bed, and they produced the buzzing/hum that the SE420's experience when plugged into the Compass. The buzz/hum was at a much lower level than with the SE420's however.

 

I'm thinking that IEMs are not the strong suit of the Compass, nor really should they be.  It is called a Headphone amp after all.  Although, after I typed that, makes me remeber when the Chinese translation was EarAmp.  Which adds at least one layer of amusement.

 

Can I listen to music? Yes I certainly can listen to music. Can I enjoy music? That really depends. I ran across this browsing Head-Fi a few days ago. I apologize to the author for not remembering her name.

 

 

 

 

 

The Compass buzz/hum completely destroys this experience and makes any music that employs silence un-enjoyable. The hum is still there with louder music, but difficult to detect because it is a much lower volume.

 

As I said before, I have taken extreme caution with the Compass and have never damaged it in any way.

 

Here is my laundry list of circumstances that produce the Buzzing/Hum:

Causes Buzzing:

  • Placing unit in any location. Buzzing not from external RF noise
  • Using "S" Super mode
  • Earth HDAM
  • Moon HDAM
  • No HDAM

This bothers me, because I have no idea what running a system with part of the circuit missing would do to it.   The fact that you know this fact, is cause for at least worry that you damaged it on my part. The HDAMs in themselves lend themselves to being plugged in halfway and backwards.  That is an issue with a piece of gear that encourages experimentation like the Compass does.

  • Increasing gain makes buzzing slightly louder
  • USB, COAX, and OPT produce buzzing
  • Using no input produces buzzing
  • Buzzing heard with sensitive headphones like Sure SE420 (In ear headphones)
  • Different power cords

 

Does not cause buzzing:

  • Unit turned off
  • switching unit to Pre-Amp only mode (not using DAC

 

 

Regards,

Evan

 

So, you should make sure it is broken.  That's the first thing. It is a headphone amp, does it work with headphones?  The fact that your IEMs are buzzing/humming does not prove there is a problem to me.  I don't know if you have noticed or not, but a common question on this forum about amps is  "how does  amp X work with brand X headphones".   Secondly, you might want to parse over the Compass threads.  I think there are two threads because the forum screwed up and I think a second was started.  There is a place in there where a mod had to be done related to Super Mode use, I think.  It might have been a hum issue.   I didn't  have the issue, so didn't pay much attention to it.  Third, are you asserting that A-GD is failing to fulfill their warranty provided when you bought the unit?  You are like at the 19th or 20th month of ownership and it seems they are saying they will fix it if you send it back, which I think was the original warranty.  I understand it is expensive to send it back, but you are insinuating they are not supporting their product, so make your justification for that.  It sounds to me that they said, send it back, we'll fix it.  That's what all companies do.  The issue is that "Large" companies in Asia have depots in many countries, A-GD hasn't progressed to that level yet.  But it really comes back to, you need to make sure it is broken in some fashion.  It may be just an incompatability with low impedance high sensitivity IEMs.  That would be the real question for the thread here.

 

I got rid of my Compass or I would try it out.  I didn't want to get rid of it, I just had too many other pieces of gear.  I liked the Compass, a lot.

post #932 of 956
Quote:
Originally Posted by les_garten View Post

See Inline, I hope this works, cause I hate this new Forum Interface.
 


Les_Garten,

 

I apologize for confusing you with my previous posts. I will attempt to address your questions as systematically and thoroughly as possible in the hope that we might be able to determine the nature of the issue I am having with the Compass (Audio-GD is not replying to me anymore).

 

You keep saying that, and it appears you are trying to bring pressure to bear here.

It's just frustrating when you type up a long, detailed explanation for a company and they disregard it. Thats all.

 

I understand an iPod can't power full size headphones well, or really at all. I also understand IEM's are designed for a low output device like an iPod and do not need much to drive them. When I use the Compass to drive the IEM's I leave the VOLUME control at about 8:30 (if you were looking at a clock). I compared the Compass to the iPod and computer because both are not high end audio equipment and both do a better job reproducing music with the SE420's. The Compass, in my mind, should not produce any humming or buzzing no matter what headphones are used, if they are used at listening volume.

 

Not true, he can't make them work with everything.  Humming can be a sign of being overdriven.  Not saying that's for sure, but you're using a big piece of Hardware to drive IEM's.

Okay, maybe not. Maybe it is overdriven, but I find that hard to believe since it plays music with the Compass, just over top of a background hum.

 

You are correct that I did not buy a new Compass two weeks ago. I am fairly certain the model was discontinued a few months back. I paid for my compass March 30th, 2009. It probably arrived a few weeks later.

 

When the Compass arrived I used it almost exclusively with my AKG K701 headphones. The Compass was always set to the lower of the gain options. I could never get the optical setting to work with the Compass, so I use the USB from my computer to deliver the digital signal.

 

So, it worked fine one minute, you started using the IEMs and they buzz.  Doesn't matter that they don't buzz with a POS iPod opamp.  The real interest here is how they do with your 701s when you get them back working.  As far as the optical not working.  Don't take this the wrong way, but most people don't know how to switch the output of their soundcards.  I've been sent a number of pieces of gear that the optical was austensibly not working and it was a Windows Control panel issue or a SC software issue with being able to switch the output.  Not saying that is what is going, just something to consider.

I never meant to imply the optical is broken. It could be, but I agree that I probably just couldn't figure out how to switch the output. Then again, the computer said it was switched and was emitting light from the optical port so I have no idea.

 

Here's an important part. I believe I used the SE420 IEMs with the compass at some point. I do not remember hearing the buzzing I hear now, though I might have just never noticed it since music drowns it out at normal listening volumes. I am to uncertain to say whether I heard it or not.

 

That of course would be an interesting fact to KNOW.

I wish my memory was better. What else can I say?

 

As I state before, I had to send in the balanced to 1/4th inch connector I use with my balanced 701s, and thus, have been using the SE420 IEM's with the compass for the past nearly three weeks. I noticed the buzzing the first time I listened to music with the Compass.

 

You noticed it the first time you used it with the IEMs, not the 701s ever, Correct?

Correct.

 

Allow me to clarify what the buzzing sounds like. The buzzing noise is just that, buzzing (or maybe a hum, I really don't understand there to be a difference between the two). Not static, not hissing, not noise. It is a buzzing that sounds like a medium frequency sound at a constant pitch. It is not piercing or low, but in the medium range of noises. It sounds like there may be an emphasis on the left channel of audio, but both channels have some buzzing. It is difficult to determine if one is louder than the other.

 

Does this noise only occur at high volume? NO. As I have tried to explain before it occurs at ALL volumes, regardless of the gain setting and regardless of whether the VOLUME is turned up. It does appear to become slightly amplified when the volume is turned up, but never rises above an annoying whisper (still clearly audible, but not amplified like music).

 

You might want to look over any wire connection in the box and see if any wire looks loose or a cracked solder joint.

I took a good look at everything and did not see any wires or connections or transistors that appeared damaged in any way.

 

The Bose headphones I used I can't really tell you much about. They were just over the ear Bose nonsense that my roommate uses.  What I can tell you is that when I cranked the gain or volume or whatever it is called, the Bose produced a nice static hiss. The same static hiss you get with all headphones when the gain is increased. The Bose headphones raised the noise floor much higher than the K701's at the Compass's maximum volume however. They also raised the noise floor higher than the SE420's at the Compass's maximum volume. The Bose did not however reproduce the buzzing of the SE420's.

 

So, the bose don't buzz and the 701s don't buzz, n'est-ce pas?  The place where hiss/noise occurs on a set of headphones will change with each set of different phones you use.  Has to do with the impedance and sesnsitivity.

I am aware of this. I suppose I am just dissapointed that the Compass introduces an "artifact" so to speak into the signal. As I have explained before, ALL signs point to the DAC circuit NOT the AMP. In my mind this means that driving the headphones to powerfully or any other amp/headphone incompatibility is a moot point. The DAC, which is a low level signal (as far as I know... thats why it needs amplified) is producing the buzzing noise. 

 

 

I also used a no-name cheap pair of Sony earbuds I listen to when I go to bed, and they produced the buzzing/hum that the SE420's experience when plugged into the Compass. The buzz/hum was at a much lower level than with the SE420's however.

 

I'm thinking that IEMs are not the strong suit of the Compass, nor really should they be.  It is called a Headphone amp after all.  Although, after I typed that, makes me remeber when the Chinese translation was EarAmp.  Which adds at least one layer of amusement.

I believe that if I used the DAC output from the compass to provide the source for a headphone amp that is compatible with IEM's the buzzing would continue. Why? I believe the DAC is causing the noise, NOT the AMP.

 

Can I listen to music? Yes I certainly can listen to music. Can I enjoy music? That really depends. I ran across this browsing Head-Fi a few days ago. I apologize to the author for not remembering her name.

 

 

 

 

 

The Compass buzz/hum completely destroys this experience and makes any music that employs silence un-enjoyable. The hum is still there with louder music, but difficult to detect because it is a much lower volume.

 

As I said before, I have taken extreme caution with the Compass and have never damaged it in any way.

 

Here is my laundry list of circumstances that produce the Buzzing/Hum:

Causes Buzzing:

  • Placing unit in any location. Buzzing not from external RF noise
  • Using "S" Super mode
  • Earth HDAM
  • Moon HDAM
  • No HDAM

This bothers me, because I have no idea what running a system with part of the circuit missing would do to it.   The fact that you know this fact, is cause for at least worry that you damaged it on my part. The HDAMs in themselves lend themselves to being plugged in halfway and backwards.  That is an issue with a piece of gear that encourages experimentation like the Compass does.

I will explain what running the system with a part of the circuit missing does. It eliminates a variable from the equation. IF, the Compass were to stop buzzing without the HDAM I would have to determine whether a) the HDAM is damaged (replace it with another HDAM) or b) the DAC cannot complete its circuit and is no longer outputting anything. What happened when I removed the HDAM is this: IT kept buzzing (so nothing changed). Great, at least I know the HDAM is not damaged.

 

Which brings me to my next point. Since you keep disregarding my assurance that I absolutely in no way, shape or form damaged the HDAM or reinstalled it improperly, let us assume I completely damaged it when I installed it. It stands to reason that since the humming/buzzing did not change with the HDAM missing, that the HDAM is irrelevant to this issue and it does not matter what condition it is in (except of course if I wanted to listen to music and not just the annoying humming noise, which I do, and have since reinstalling the HDAM).

 

  • Increasing gain makes buzzing slightly louder
  • USB, COAX, and OPT produce buzzing
  • Using no input produces buzzing
  • Buzzing heard with sensitive headphones like Sure SE420 (In ear headphones)
  • Different power cords

 

Does not cause buzzing:

  • Unit turned off
  • switching unit to Pre-Amp only mode (not using DAC

 

 

Regards,

Evan

 

So, you should make sure it is broken.  That's the first thing. It is a headphone amp, does it work with headphones?  The fact that your IEMs are buzzing/humming does not prove there is a problem to me.  I don't know if you have noticed or not, but a common question on this forum about amps is  "how does  amp X work with brand X headphones".   Secondly, you might want to parse over the Compass threads.  I think there are two threads because the forum screwed up and I think a second was started.  There is a place in there where a mod had to be done related to Super Mode use, I think.  It might have been a hum issue.   I didn't  have the issue, so didn't pay much attention to it.  Third, are you asserting that A-GD is failing to fulfill their warranty provided when you bought the unit?  You are like at the 19th or 20th month of ownership and it seems they are saying they will fix it if you send it back, which I think was the original warranty.  I understand it is expensive to send it back, but you are insinuating they are not supporting their product, so make your justification for that.  It sounds to me that they said, send it back, we'll fix it.  That's what all companies do.  The issue is that "Large" companies in Asia have depots in many countries, A-GD hasn't progressed to that level yet.  But it really comes back to, you need to make sure it is broken in some fashion.  It may be just an incompatability with low impedance high sensitivity IEMs.  That would be the real question for the thread here.

 

I guess A-GD is being far to ambiguous for my liking. I don't want to ship the amp all the way to China to have them say "Works with our headphones, please provide return postage." They haven't seemed to take a word I've said seriously or into consideration or at least tried to have a conversation about it with me like you have.

 

I got rid of my Compass or I would try it out.  I didn't want to get rid of it, I just had too many other pieces of gear.  I liked the Compass, a lot.

 

At this point it seems like I'm at the end of the road. Maybe I'll buy a DAC that works with all types of headphones, not just ones that aren't sensitive enough to reveal it's design flaws.

 

edit;typo

post #933 of 956

I apologize for confusing you with my previous posts. I will attempt to address your questions as systematically and thoroughly as possible in the hope that we might be able to determine the nature of the issue I am having with the Compass (Audio-GD is not replying to me anymore).

 

You keep saying that, and it appears you are trying to bring pressure to bear here.

It's just frustrating when you type up a long, detailed explanation for a company and they disregard it. Thats all.

Long detailed explanations they have trouble with.  You need to send simple, brief, and clear communications to them.  You send them a bunch of paragraphs and it's too much for them.  You also shouldn't use contractions or idioms.  I read all my correspondence with them over very carefully to make it as simple as possible to comprehend and try to make sure nothing can be interpreted 2 ways.  I send my PM's like it was being written for a 6 year old.  I don't mean this in an insulting fashion.  I just try to make it easy for them to understand.

 

I understand an iPod can't power full size headphones well, or really at all. I also understand IEM's are designed for a low output device like an iPod and do not need much to drive them. When I use the Compass to drive the IEM's I leave the VOLUME control at about 8:30 (if you were looking at a clock). I compared the Compass to the iPod and computer because both are not high end audio equipment and both do a better job reproducing music with the SE420's. The Compass, in my mind, should not produce any humming or buzzing no matter what headphones are used, if they are used at listening volume.

 

Not true, he can't make them work with everything.  Humming can be a sign of being overdriven.  Not saying that's for sure, but you're using a big piece of Hardware to drive IEM's.

Okay, maybe not. Maybe it is overdriven, but I find that hard to believe since it plays music with the Compass, just over top of a background hum.

 

Ok, let's simplify.  Let's say you get 10 more sets of headphones and they all play well.  Real headphones, that is.  What would you assume at that point?

 

You are correct that I did not buy a new Compass two weeks ago. I am fairly certain the model was discontinued a few months back. I paid for my compass March 30th, 2009. It probably arrived a few weeks later.

 

When the Compass arrived I used it almost exclusively with my AKG K701 headphones. The Compass was always set to the lower of the gain options. I could never get the optical setting to work with the Compass, so I use the USB from my computer to deliver the digital signal.

 

So, it worked fine one minute, you started using the IEMs and they buzz.  Doesn't matter that they don't buzz with a POS iPod opamp.  The real interest here is how they do with your 701s when you get them back working.  As far as the optical not working.  Don't take this the wrong way, but most people don't know how to switch the output of their soundcards.  I've been sent a number of pieces of gear that the optical was austensibly not working and it was a Windows Control panel issue or a SC software issue with being able to switch the output.  Not saying that is what is going, just something to consider.

I never meant to imply the optical is broken. It could be, but I agree that I probably just couldn't figure out how to switch the output. Then again, the computer said it was switched and was emitting light from the optical port so I have no idea.

 

When you turn on the computer, light comes out.  That doesn't mean there is any data in that light.  The light is just a light, an LED as it were.  Won't have any data on it till you set the SC to route data to it.  Light will always be there.  Unless you go out of your way, it will not be active.  VERY common problem.

 

Here's an important part. I believe I used the SE420 IEMs with the compass at some point. I do not remember hearing the buzzing I hear now, though I might have just never noticed it since music drowns it out at normal listening volumes. I am to uncertain to say whether I heard it or not.

 

That of course would be an interesting fact to KNOW.

I wish my memory was better. What else can I say?

 

As I state before, I had to send in the balanced to 1/4th inch connector I use with my balanced 701s, and thus, have been using the SE420 IEM's with the compass for the past nearly three weeks. I noticed the buzzing the first time I listened to music with the Compass.

 

You noticed it the first time you used it with the IEMs, not the 701s ever, Correct?

Correct.

 

Allow me to clarify what the buzzing sounds like. The buzzing noise is just that, buzzing (or maybe a hum, I really don't understand there to be a difference between the two). Not static, not hissing, not noise. It is a buzzing that sounds like a medium frequency sound at a constant pitch. It is not piercing or low, but in the medium range of noises. It sounds like there may be an emphasis on the left channel of audio, but both channels have some buzzing. It is difficult to determine if one is louder than the other.

 

Does this noise only occur at high volume? NO. As I have tried to explain before it occurs at ALL volumes, regardless of the gain setting and regardless of whether the VOLUME is turned up. It does appear to become slightly amplified when the volume is turned up, but never rises above an annoying whisper (still clearly audible, but not amplified like music).

 

You might want to look over any wire connection in the box and see if any wire looks loose or a cracked solder joint.

I took a good look at everything and did not see any wires or connections or transistors that appeared damaged in any way.

 

The Bose headphones I used I can't really tell you much about. They were just over the ear Bose nonsense that my roommate uses.  What I can tell you is that when I cranked the gain or volume or whatever it is called, the Bose produced a nice static hiss. The same static hiss you get with all headphones when the gain is increased. The Bose headphones raised the noise floor much higher than the K701's at the Compass's maximum volume however. They also raised the noise floor higher than the SE420's at the Compass's maximum volume. The Bose did not however reproduce the buzzing of the SE420's.

 

So, the bose don't buzz and the 701s don't buzz, n'est-ce pas?  The place where hiss/noise occurs on a set of headphones will change with each set of different phones you use.  Has to do with the impedance and sesnsitivity.

I am aware of this. I suppose I am just dissapointed that the Compass introduces an "artifact" so to speak into the signal. As I have explained before, ALL signs point to the DAC circuit NOT the AMP. In my mind this means that driving the headphones to powerfully or any other amp/headphone incompatibility is a moot point. The DAC, which is a low level signal (as far as I know... thats why it needs amplified) is producing the buzzing noise. 

 

Only with IEMs.  You have shown that this Headphone amp has a problem with Headphones.

 

 

I also used a no-name cheap pair of Sony earbuds I listen to when I go to bed, and they produced the buzzing/hum that the SE420's experience when plugged into the Compass. The buzz/hum was at a much lower level than with the SE420's however.

 

I'm thinking that IEMs are not the strong suit of the Compass, nor really should they be.  It is called a Headphone amp after all.  Although, after I typed that, makes me remeber when the Chinese translation was EarAmp.  Which adds at least one layer of amusement.

I believe that if I used the DAC output from the compass to provide the source for a headphone amp that is compatible with IEM's the buzzing would continue. Why? I believe the DAC is causing the noise, NOT the AMP.

Let us know how that experiment works out.

 

Can I listen to music? Yes I certainly can listen to music. Can I enjoy music? That really depends. I ran across this browsing Head-Fi a few days ago. I apologize to the author for not remembering her name.

 

 

 

 

 

The Compass buzz/hum completely destroys this experience and makes any music that employs silence un-enjoyable. The hum is still there with louder music, but difficult to detect because it is a much lower volume.

 

As I said before, I have taken extreme caution with the Compass and have never damaged it in any way.

 

Here is my laundry list of circumstances that produce the Buzzing/Hum:

Causes Buzzing:

  • Placing unit in any location. Buzzing not from external RF noise
  • Using "S" Super mode
  • Earth HDAM
  • Moon HDAM
  • No HDAM

This bothers me, because I have no idea what running a system with part of the circuit missing would do to it.   The fact that you know this fact, is cause for at least worry that you damaged it on my part. The HDAMs in themselves lend themselves to being plugged in halfway and backwards.  That is an issue with a piece of gear that encourages experimentation like the Compass does.

I will explain what running the system with a part of the circuit missing does. It eliminates a variable from the equation. IF, the Compass were to stop buzzing without the HDAM I would have to determine whether a) the HDAM is damaged (replace it with another HDAM) or b) the DAC cannot complete its circuit and is no longer outputting anything. What happened when I removed the HDAM is this: IT kept buzzing (so nothing changed). Great, at least I know the HDAM is not damaged.

 

Which brings me to my next point. Since you keep disregarding my assurance that I absolutely in no way, shape or form damaged the HDAM or reinstalled it improperly, let us assume I completely damaged it when I installed it. It stands to reason that since the humming/buzzing did not change with the HDAM missing, that the HDAM is irrelevant to this issue and it does not matter what condition it is in (except of course if I wanted to listen to music and not just the annoying humming noise, which I do, and have since reinstalling the HDAM).

 

None of your logic makes sense here.  Look at a HDAM.  It is a bunch of resistors, transistors, and capacitors.  You took those out of the circuit and fired it up?  Do that to your TV and see how it does?  The HDAM is part of the circuit.  You should ask KW if running without the HDAM would damage the DAC.  That would be a good question to know the answer to.  I don't have the balls to try it.  I also don't know how many times doing that experiment that you would get away with it.  I am not prepared to underwrite the cost of the experiment as you were.

 

  • Increasing gain makes buzzing slightly louder
  • USB, COAX, and OPT produce buzzing
  • Using no input produces buzzing
  • Buzzing heard with sensitive headphones like Sure SE420 (In ear headphones)
  • Different power cords

 

Does not cause buzzing:

  • Unit turned off
  • switching unit to Pre-Amp only mode (not using DAC

 

 

Regards,

Evan

 

So, you should make sure it is broken.  That's the first thing. It is a headphone amp, does it work with headphones?  The fact that your IEMs are buzzing/humming does not prove there is a problem to me.  I don't know if you have noticed or not, but a common question on this forum about amps is  "how does  amp X work with brand X headphones".   Secondly, you might want to parse over the Compass threads.  I think there are two threads because the forum screwed up and I think a second was started.  There is a place in there where a mod had to be done related to Super Mode use, I think.  It might have been a hum issue.   I didn't  have the issue, so didn't pay much attention to it.  Third, are you asserting that A-GD is failing to fulfill their warranty provided when you bought the unit?  You are like at the 19th or 20th month of ownership and it seems they are saying they will fix it if you send it back, which I think was the original warranty.  I understand it is expensive to send it back, but you are insinuating they are not supporting their product, so make your justification for that.  It sounds to me that they said, send it back, we'll fix it.  That's what all companies do.  The issue is that "Large" companies in Asia have depots in many countries, A-GD hasn't progressed to that level yet.  But it really comes back to, you need to make sure it is broken in some fashion.  It may be just an incompatability with low impedance high sensitivity IEMs.  That would be the real question for the thread here.

 

I guess A-GD is being far to ambiguous for my liking. I don't want to ship the amp all the way to China to have them say "Works with our headphones, please provide return postage." They haven't seemed to take a word I've said seriously or into consideration or at least tried to have a conversation about it with me like you have.

 

I got rid of my Compass or I would try it out.  I didn't want to get rid of it, I just had too many other pieces of gear.  I liked the Compass, a lot.

 

At this point it seems like I'm at the end of the road. Maybe I'll buy a DAC that works with all types of headphones, not just ones that aren't sensitive enough to reveal it's design flaws.

 

As I asked above, where have they violated their warranty?  Additionally, you haven't proven anything is wrong with the gear except that it doesn't like your IEMs.  Get some real canz, see if it works.  Sell it if you don't want it, or send it to them for "repair" under warranty.  Seems clear as crystal to me.

 

Ohhh, and quit running it with the HDAMs out...

post #934 of 956

Les,

 

The fact of the mater is that something in the compass is creating a noise that is not part of the music. The noise goes away when the DAC board is not in use. The DAC is meant to convert digital information to an analogue signal. From this alone it seems that the DAC is creating this extra noise. Insofar as this is true, we have a problem. The DAC is not supposed to produce any noise other than what is provided for by the digital signal, let alone a very audible hum. Just because most equipment isn't able to detect this hum does not mean it does not exist.  

 

You seem very quick to dismiss my criticism of the Compass. I can tell you like Audio g-d's products and the compass is no exception. Suspend your pre-concieved notions for a minute and look at what I am telling you is happening. Unless you really believe, despite everything I have told you, that the AMP introduces this sound and not the DAC, I think you will agree that the Compass is introducing a noise that it should not be. This might be a design flaw or it might simply be an issue with my unit, but I do not think it is reasonable to say there is no real issue to address. I may be misinterpreting your comments, but the sentiment I have gathered is that you feel I am doing something wrong by using the Compass with IEM's, not that the Compass is introducing a noise that should not be there. 

 

Thanks for the help so far. It seems like I'm at the end of the line. As I said before, I can't justify sending the unit back to China to get "repaired', especially if Kingwa and the rest of Audio-GD are going to express similarly dismissive opinions.

 

By the way, I noticed the noise before running the unit without the HDAM. It didn't get worse after running it with the HDAM out either. You may be skeptical, but until I see evidence that suggests otherwise I am inclined to believe the Compass did not sustain damage. 

post #935 of 956

Never mind...

 

Sounds like you have it all figured out...
 

Quote:
Originally Posted by EvanLikesFruit View Post

Les,

 

The fact of the mater is that something in the compass is creating a noise that is not part of the music. The noise goes away when the DAC board is not in use. The DAC is meant to convert digital information to an analogue signal. From this alone it seems that the DAC is creating this extra noise. Insofar as this is true, we have a problem. The DAC is not supposed to produce any noise other than what is provided for by the digital signal, let alone a very audible hum. Just because most equipment isn't able to detect this hum does not mean it does not exist.  

 

You seem very quick to dismiss my criticism of the Compass. I can tell you like Audio g-d's products and the compass is no exception. Suspend your pre-concieved notions for a minute and look at what I am telling you is happening. Unless you really believe, despite everything I have told you, that the AMP introduces this sound and not the DAC, I think you will agree that the Compass is introducing a noise that it should not be. This might be a design flaw or it might simply be an issue with my unit, but I do not think it is reasonable to say there is no real issue to address. I may be misinterpreting your comments, but the sentiment I have gathered is that you feel I am doing something wrong by using the Compass with IEM's, not that the Compass is introducing a noise that should not be there. 

 

Thanks for the help so far. It seems like I'm at the end of the line. As I said before, I can't justify sending the unit back to China to get "repaired', especially if Kingwa and the rest of Audio-GD are going to express similarly dismissive opinions.

 

By the way, I noticed the noise before running the unit without the HDAM. It didn't get worse after running it with the HDAM out either. You may be skeptical, but until I see evidence that suggests otherwise I am inclined to believe the Compass did not sustain damage. 

post #936 of 956
Thread Starter 

Les is being grumpy.   Plug it in as a DAC to another amp and tell us whether you still get buzzing.

post #937 of 956

I'll get back to you guys in the next few days. I'm wrapping up finals tomorrow and will see if the local Hi-Fi shop can volunteer the use of an amplifier or two. 

post #938 of 956

Hi how is the Compass when plugged into a Darkvoice amp? Currently looking around for a DAC to improve my source ( My amp is plugged directly to my mobo's line out jack )

post #939 of 956

Should be good, but I think you should get an NFB-3 instead.

post #940 of 956

how much is an NFB-3 used going for?  I think I can't afford a brand new set haha

post #941 of 956

Hi I take this thread to ask  a response.
I have a mac connected via optical to the compass, the compass connected to the output pre to the amp.
Supermode off, output pre on.
The DAC converter inside the compass works? or bypass

 

many thanks


Edited by 55dsl - 12/15/11 at 2:51pm
post #942 of 956

yes...but at dac-out rca. if you wish to use dac+preamp output...u have route from dac out to line-in then line-out to amp.

post #943 of 956
Quote:
Originally Posted by rioven View Post

yes...but at dac-out rca. if you wish to use dac+preamp output...u have route from dac out to line-in then line-out to amp.



Ok ..yes but as you say the same thing.

 

1 MAC > INPUT OPTICAL COMPASS > OUT PRE > AMP

2 MAC > IMPUT OPTICAL > DAC OUT > LINE IN COMPASS > OUT PRE > AMP the sound is equal if you push the button on or off Supermode !!

 

Thanks

post #944 of 956
Thread Starter 

That's right. Super mode disconnects the DAC and headphone/pre-amp. So in Super mode, connecting the DAC out to the Line In with a pair of cables has the same effect as turning Super mode off.

 

If you are using a digital input (optical, USB or coax), it is going through the DAC regardless, as a digital input has to be converted to analogue somewhere.

post #945 of 956

My compass has been a workhorse for years now, but something has gone wrong.  I can no longer get any audio output.

 

My setup has been dead simple; Computer -> (USB) -> Compass -> Headphones (front output) / Speakers (rear output); switching between them with the Super button.

 

Now, I am getting zero signal out of either output; even when I crank the volume as high as it will go.  My computer still detects the DAC though, when I power on and off the unit Windows reacts as expected.

 

The most alarming thing though is, the unit no longer gets hot.  This leaves me to believe that there is a power issue somewhere in the unit.  The front power LED still works though.

 

Any suggestions on what could be wrong?  I do have a multimeter to help.

 

Worst case scenario though; I've been looking for an excuse to buy a Xonar.  This might be it.

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