The Stax Thread III

[chinsettawong]

If your headphones are old, it might take a little time to charge up.  Normally, it should take only a few minutes.  But if you have brand new ones, the charge up time is almost instantaneous.

 

[Bloos]

The ones I have are the L300s, and used them for a bit over a month, and I feel like the distortion goes away in about a minute or two.
Hoping that's normal. I guess this also depends on the time since they were last used? (~a week for me)

 

[chinsettawong]

L300 is so new. It shouldn't have this problem. Could it be your amp? What amp do you use with the headphones?

 

[Bloos]

L300 is so new. It shouldn't have this problem. Could it be your amp? What amp do you use with the headphones?

The SRM 252S

 

[Bloos]

Huh, Wierd thing... After testing today. I realized that the distortion doesn't go away after a while, but instead actually goes away when I turn on my amp (O2 amp) connected to the parallel outs of the 252S. (also goes away when disconnecting the O2 amp)
 
Wieeerd? anyone know why this might be?
(Whoa, connecting a different amp to the parallel outs, Fiio E10, makes the distortion much worse)

 

[gefski]

Huh, Wierd thing... After testing today. I realized that the distortion doesn't go away after a while, but instead actually goes away when I turn on my amp (O2 amp) connected to the parallel outs of the 252S. (also goes away when disconnecting the O2 amp)

Wieeerd? anyone know why this might be?
(Whoa, connecting a different amp to the parallel outs, Fiio E10, makes the distortion much worse)

What is the nature of the "distortion", what does it sound like? Connecting different amps to parallel outputs would suggest a ground loop, but that would be a hum, not distortion.

 

[Bloos]

What is the nature of the "distortion", what does it sound like? Connecting different amps to parallel outputs would suggest a ground loop, but that would be a hum, not distortion.

it's like a buzzing static that consistently happens in certain parts of a song.
But the sound definitely goes away after disconnecting the amp, so its not from the audio file.
Also if at a part where I hear it only in one ear, after switching the L and R connections, the buzz switches to the other ear.

 

[joseph69]

  it's like a buzzing static that consistently happens in certain parts of a song.
But the sound definitely goes away after disconnecting the amp, so its not from the audio file.
Also if at a part where I hear it only in one ear, after switching the L and R connections, the buzz switches to the other ear.

  Bad interconnect?

 

[zolkis]

It may be the amp's (or power supply) issue. The 252S deserves a better PSU for sure. Go to your Stax dealer and listen your headphones with other amps. Then you will know. 

 

[astrostar59]

Sounds like a cap is going letting DC through. Can you get hold of a meter and measure the outputs for DC?

 

[Bloos]

 
Sounds like a cap is going letting DC through. Can you get hold of a meter and measure the outputs for DC?

Which outputs are you referring to?

 

[astrostar59]

  Which outputs are you referring to?

The RCA or XLRs out. I had a pre-amp that did the same thing, caps were going and it gave out a wandering and inconsistent static noise which turned out to be DC. One of your pre-amps may have better input shielding that repels the DC, the others not, hens the change there.
 
It is an idea that can be easily checked. Other ideas may be more costly and need a tech.

 

[miko64]

@Zolkis: I use sr007/2 and sr252 with a 12V 10ah battery together with Chord Hugo which results in a very nice combo. The power supply is as a consequence extremely stable

 

[Bloos]

I don't have a working meter at the moment, but do you mean the ouputs of the 252S or my other Amp?
 
I also tested: 
1. Using different cables (at every connection)
2. Splitting the audio signal from the DAC into two, one to the 252S and one to the other amp, instead of using the parallel outs of the 252S.
 
And in both these cases it seems as long as another Amp (while it is off) is attached, there is this "distortion".

 

[kevin gilmore]

opamp input based amps (like o2) are going to clamp the audio signal when turned off to protect the chip.
the solution seems obvious.