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).
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.
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.
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.
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.
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).
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.
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.
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.
Quote:
Silence has been a fundamental building block of classical music composition for over hundred years. And pauses all have well defined lengths for a much longer time. The silence of a pause intends to present a different perspective to the just heard as it decays in the acoustic short term memory and generally throws back the listener's attention at himself.
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:
[size=10.0pt]Causes Buzzing:[/size]
- [size=10.0pt]Placing unit in any location. Buzzing not from external RF noise[/size]
- [size=10.0pt]Using "S" Super mode[/size]
- [size=10.0pt]Earth HDAM[/size]
- [size=10.0pt]Moon HDAM[/size]
- [size=10.0pt]No HDAM[/size]
- [size=10.0pt]Increasing gain makes buzzing slightly louder[/size]
- [size=10.0pt]USB, COAX, and OPT produce buzzing[/size]
- [size=10.0pt]Using no input produces buzzing[/size]
- [size=10.0pt]Buzzing heard with sensitive headphones like Sure SE420 (In ear headphones)[/size]
- [size=10.0pt]Different power cords[/size]
[size=10.0pt]Does not cause buzzing:[/size]
- [size=10.0pt]Unit turned off[/size]
- [size=10.0pt]switching unit to Pre-Amp only mode (not using DAC[/size]
Regards,
Evan
