[koreill1]

Hey Guys,
 
I have a pair of Sennheiser HD650s that I picked up about a year ago.  I've been using them on my computer with a Nuforce uDAC-2 running into a LittleDot MK III amp.  They worked great for awhile, but now I'm having some confusing problems.
 
1) The left speaker was buzzing, and mostly playing only the lows, so I took the pads off to clean out any stray hairs/dust.  I found nothing, and when I plugged it back it, it worked.
2) Moments later, the right speaker started buzzing (same problem/sound), so I did the same.  I plugged it back in, and it still buzzed.
3) I plugged the headphones directly into an iPod, and cranked the volume - both speakers worked flawlessly.
4) When I plugged back into my computer/amp, the headphones worked great for about 2 seconds, then the right speaker started buzzing again.
5) I've been able to repeat 3 and 4 a couple times.
 
 
The LittleDot amp puts out 350mW of power at 300ohms (same resistance as the Senn 650s) - any idea if/why the amp may be causing this?
 
Thanks

 

[wolfetan44]

Quote:

Hey Guys,
 
I have a pair of Sennheiser HD650s that I picked up about a year ago.  I've been using them on my computer with a Nuforce uDAC-2 running into a LittleDot MK III amp.  They worked great for awhile, but now I'm having some confusing problems.
 
1) The left speaker was buzzing, and mostly playing only the lows, so I took the pads off to clean out any stray hairs/dust.  I found nothing, and when I plugged it back it, it worked.
2) Moments later, the right speaker started buzzing (same problem/sound), so I did the same.  I plugged it back in, and it still buzzed.
3) I plugged the headphones directly into an iPod, and cranked the volume - both speakers worked flawlessly.
4) When I plugged back into my computer/amp, the headphones worked great for about 2 seconds, then the right speaker started buzzing again.
5) I've been able to repeat 3 and 4 a couple times.
 
 
The LittleDot amp puts out 350mW of power at 300ohms (same resistance as the Senn 650s) - any idea if/why the amp may be causing this?
 
Thanks

Sounds like something is wrong with the speakers in the HD650's. Or the amp. Or DAC. lol.

 

[zeinharis]

The tubes perhaps, have you tried to change the tubes?

 

[dsound]

I would try to eliminate items from your signal chain to isolate the problem.  Try:
Computer>uDac>650's 
Ipod>Little Dot MKIII>650's  
 

 

[davidgotsa]

Are you plugging the amp into a grounded outlet? Try moving the amp around your house to different ones to see what happens. 
 
I also had that problem for a while before I realized what was going on. 

 

[koreill1]

The headphone has the same buzzing problem whether it's plugged into the Amp, or into the DAC directly.
 
I have not tried to change the tubes, but since they have the same problem directly into the DAC, I'm not sure the tubes are the issue...

 

[ProTofik]

Do you have any other headphones to try them with your setup?

 

[xaval]

Quote:

Hey Guys,
 
I have a pair of Sennheiser HD650s that I picked up about a year ago.  I've been using them on my computer with a Nuforce uDAC-2 running into a LittleDot MK III amp.  They worked great for awhile, but now I'm having some confusing problems.
 
1) The left speaker was buzzing, and mostly playing only the lows, so I took the pads off to clean out any stray hairs/dust.  I found nothing, and when I plugged it back it, it worked.
2) Moments later, the right speaker started buzzing (same problem/sound), so I did the same.  I plugged it back in, and it still buzzed.
3) I plugged the headphones directly into an iPod, and cranked the volume - both speakers worked flawlessly.
4) When I plugged back into my computer/amp, the headphones worked great for about 2 seconds, then the right speaker started buzzing again.
5) I've been able to repeat 3 and 4 a couple times.
 
 
The LittleDot amp puts out 350mW of power at 300ohms (same resistance as the Senn 650s) - any idea if/why the amp may be causing this?
 
Thanks

The problem doesn't seem to be with the heaphones then.
The most common problem would be either a grounding issue with the DAC or Amp or a troublesome tube within the amp.

 

[koreill1]

Quote:

The problem doesn't seem to be with the heaphones then.
The most common problem would be either a grounding issue with the DAC or Amp or a troublesome tube within the amp.

Nailed it... It was a grounding issue with the DAC, which I found by removing the DAC from the equation and using iPod/Amp only.
 
Put the system back together and I'm back in audio bliss.
 
Thanks All!

 

[xaval]

Welcome to Headfi koreill1
Sorry about your grounding issue... erm wallet!