[Fungus]

I just got my c5 I totally agree.  
 
The only gripe is the background hiss is quite loud when using my um3x.
 
Is this normal because I heard one of the benefits of the c5 is having a complete black background. 
 
Another niggle is when I switch it off, I can sometimes hear a pop. I'm concern that it may damage my iems. 

 

[FiJAAS]

No hiss or pops here on my end.

 

[miceblue]

I just got my c5 I totally agree.  

The only gripe is the background hiss is quite loud when using my um3x.

Is this normal because I heard one of the benefits of the c5 is having a complete black background. 

Another niggle is when I switch it off, I can sometimes hear a pop. I'm concern that it may damage my iems. 

I only heard a slight hiss with custom in-ear monitors. Other than that, the background hiss should be pretty much non-existent.

 

[jseaber]

  I just got my c5 I totally agree.  
 
The only gripe is the background hiss is quite loud when using my um3x.
 
Is this normal because I heard one of the benefits of the c5 is having a complete black background. 
 
Another niggle is when I switch it off, I can sometimes hear a pop. I'm concern that it may damage my iems. 

 
@Fungus: What audio source, and how is volume set at the source and amp? This sounds like a source issue. C5's published noise floor is excellent and should be very quiet with sensitive IEMs, if not inaudible. You may be experiencing a noisy source.
 
Many portable amps exhibit turn on/off transients. This is normal and will not damage your IEMs. If you're concerned, simply connect the headphones after the amp is switched on.

 

[jseaber]

  Does anybody know where I can buy this tiny interconnect connector.  
 
Apparently it can be bought from jds labs with the purchase of the c5 as an option accessory according to a review a read but when I went on the website, it's not listed?
 

 
We have 5000 of these cables in production now. They'll be available soon!

 

[Fungus]

Source is from my sony hd5 via lineout.

 

[jseaber]

Source is from my sony hd5 via lineout.

 
I'm having trouble finding an exact noise or SNR specification for the Sony HD5. A few searches suggest it's close to 95dB for the line-output, which would be rather noisy for high efficiency IEMs. Please correct me if this is bad information.
 
Have you tried any other audio sources? What happens if you disconnect the audio input cable and turn volume towards the minimum position? If noise is minimized this way, you have source noise.

 

[ClieOS]

   
We have 5000 of these cables in production now. They'll be available soon!

 
Nice, gonna get myself a pair!

 

[Fungus]

   
I'm having trouble finding an exact noise or SNR specification for the Sony HD5. A few searches suggest it's close to 95dB for the line-output, which would be rather noisy for high efficiency IEMs. Please correct me if this is bad information.
 
Have you tried any other audio sources? What happens if you disconnect the audio input cable and turn volume towards the minimum position? If noise is minimized this way, you have source noise.

Yes I tried disconnecting the audio input cable from the source and could still heard the same level of hiss.  
 
It's definitely the c5, not the source (hd5). 

 

[Fungus]

I've had another listening with the volume set to minimum position.
 
The hiss is quite minimal but is still audible in a quiet environment.
 
However, when the volume to turned up to iem listening levels with no music player, the hiss is clearly evident.
 
On the bright side, the hiss doesn't increase a lot more once I turned the volume to maximum. 
 
This test is done without the source connected, just my um3x connected to the output jack. 
 
Charging while playing doesn't increase the hiss at all. 
 
Switching the power off does cause a pop. 

 

[jseaber]

  Yes I tried disconnecting the audio input cable from the source and could still heard the same level of hiss.  
 
It's definitely the c5, not the source (hd5). 

 
C5's published noise floor is -107dbV, which is quite low. Highly sensitive IEMs will yield slightly audible hiss with even the best source/amp; a truly black background is nearly impossible with 124 db/mW headphones like UM3X. Still, hiss should be incredibly quiet @ -107dbV . Feel free to email us if you need further inspection.

 

[skamp]

a truly black background is nearly impossible with 124 db/mW headphones like UM3X.

I don't understand the point of such ridiculously high sensitivity. It's more of a flaw than anything else.

 

[Fungus]

Ok, I tested the c5 again the background noise is pretty much non existent.  
 
The reason why I initially found the hissing to be so loud was because it was set to high volume on high gain with no music playing. 
 
However having said that, I'm still getting the a popping noise ever-time I switch off the amp. 

 

[Fungus]

I don't understand the point of such ridiculously high sensitivity. It's more of a flaw than anything else.

I agree but on the other hand it's useful for testing out the background noise level of equipments. 

 

[skamp]

The reason why I initially found the hissing to be so loud was because it was set to high volume on high gain with no music playing.

You definitely don't want to set the C5 to high gain with those IEMs, ever.