[Fungus]

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

Unless I set the volume position to low. I always prefer listening to my um3x on high gain regardless of the amp. 
 
It also means I don't have to change back the gain to high when I'm using other headphones that require the power. 

 

[skamp]

Unless I set the volume position to low. I always prefer listening to my um3x on high gain regardless of the amp.

Sorry, but you're doing it wrong. You complain about "quite loud hiss": this is why. High gain with those IEMs will make them sound worse, not better.

It also means I don't have to change back the gain to high when I'm using other headphones that require the power. 

I can only imagine the sheer effort required to push a button…

 

[mandrake50]

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

If you would post here when they are available, I would appreciate it. This looks just like what I have been looking for.

 

[jseaber]

 
If you would post here when they are available, I would appreciate it. This looks just like what I have been looking for.

 
Will do!

 

[mandrake50]

  Unless I set the volume position to low. I always prefer listening to my um3x on high gain regardless of the amp. 
 
It also means I don't have to change back the gain to high when I'm using other headphones that require the power. 

Try low gain and let us know the results.
I have the C5D and do not notice any background hiss on low gain at max volume settings (no signal) with high sensitivity IEMs.
 
Not sure why you would worry about having to change a setting when changing among headphones or IEMs... that is why it is there.

 

[skamp]

He did already:

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.

 

[gauchotodd]

I just got my C5D and can't get it to work through my LG G3. It's plug and play with the micro-mini USB through my Galaxy Tab, and both are running 4.4.2 (G3 is stock, Tab is a custom ROM, not CM). The only troubleshooting I could think to do was to enable USB debugging and reboot, but that didn't solve it, it still plays through the phone speaker instead of through the C5D.
 
Also, when playing through my Tab, after a couple songs (~8-10 minutes) I will start to hear a light pop/crackle that gets progressively worse. If I pause it, wait a moment, then resume playback it goes away, and I've noticed it on both gain settings and with or without bass boost. Power indicator is solid green, and is set to BAT... wondering if it may be a lemon?

 

[Fungus]

 
I have the C5D and do not notice any background hiss on low gain at max volume settings (no signal) with high sensitivity IEMs.

I've tried switching between low and high again and the level of background hiss is identical. It's mainly when I turn the volume over 10 steps that the hiss increases. When I set the volume to max on both gain setting, I can definitely hear the hiss, not just with my um3x, but with my other full size headphones. 
 
I find this peculiar since the c5 and objective2 which I also own share the same noise floor rating of -107dBV yet it is clearly evident to my ears that the o2 is much quieter at listening levels. 
 
I'm not sure if my c5 is defective cos it's just about dead quiet with the volume turned all all the way down yet as I increase the volume to normal listening levels with my highly sensitive um3xs, the hiss level dramatically increases.  
 
I'm also getting the pop every time the amp is turned off as mentioned before. 
 
I'm currently contemplating whether I should send it back to get it tested or just ask for an exchange since I bought it from a local shop not far from my home.  
 
It's a shame cos besides these issues, I'm really enjoying it. 

 

[FiJAAS]

I can confirm a slight hiss when I trun the volume up or down with no music playing. Tested with Sennisheiser cx500, ipod classic and fiio l9.

 

[jseaber]

  I've tried switching between low and high again and the level of background hiss is identical. It's mainly when I turn the volume over 10 steps that the hiss increases. When I set the volume to max on both gain setting, I can definitely hear the hiss, not just with my um3x, but with my other full size headphones. 
 
I find this peculiar since the c5 and objective2 which I also own share the same noise floor rating of -107dBV yet it is clearly evident to my ears that the o2 is much quieter at listening levels. 
 
I'm not sure if my c5 is defective cos it's just about dead quiet with the volume turned all all the way down yet as I increase the volume to normal listening levels with my highly sensitive um3xs, the hiss level dramatically increases.  
 
I'm also getting the pop every time the amp is turned off as mentioned before. 
 
I'm currently contemplating whether I should send it back to get it tested or just ask for an exchange since I bought it from a local shop not far from my home.  
 
It's a shame cos besides these issues, I'm really enjoying it. 

 
We'll gladly re-inspect your C5 on our audio analyzer. Turn on/off transients are normal, and it's also normal for hiss to be present with 124db/mW headphones and for that hiss to increase proportionally with volume. Let us know how we can help.

 

[mandrake50]

I can confirm a slight hiss when I trun the volume up or down with no music playing. Tested with Sennisheiser cx500, ipod classic and fiio l9.

I wonder if you are not referring to something other than what Fungus is hearing. I thought that he was talking about background "hiss"/noise all of the time. Maybe I am the one not getting it though.
I just turned my C5D on and plugged in my RE 400s. No source connected as this will isolate any noise to only coming from the C5D.
I ran the volume to max and back to minimum. While the digital control is tracking I can hear a low sort of clicking sound. It is almost like static, keeping time with the digital volume steps...not what I would call hiss... or any kind of continuous background noise of any kind.
 
At either extreme of the volume control or anywhere in the middle, once I stopped changing the volume level, there is no detectable noise. The thing, with those IEMs and my ears, had a pitch black noise free background.
 
Fungus, have you tried to see if your noise is present when the C5 is not connected to anything other than your IEMs ?
 
If you still hear noise all of the time, I would think about that exchange. You can send it to JDS and I think that they will take care of you. I sent my C5D in for something I messed up. I sent it on Monday and had it back on Friday of the same week. Hard to beat going to a local store and just walking out with a new unit though.

 

[Fungus]

 
I wonder if you are not referring to something other than what Fungus is hearing. I thought that he was talking about background "hiss"/noise all of the time. Maybe I am the one not getting it though.
I just turned my C5D on and plugged in my RE 400s. No source connected as this will isolate any noise to only coming from the C5D.
I ran the volume to max and back to minimum. While the digital control is tracking I can hear a low sort of clicking sound. It is almost like static, keeping time with the digital volume steps...not what I would call hiss... or any kind of continuous background noise of any kind.
 
At either extreme of the volume control or anywhere in the middle, once I stopped changing the volume level, there is no detectable noise. The thing, with those IEMs and my ears, had a pitch black noise free background.
 
Fungus, have you tried to see if your noise is present when the C5 is not connected to anything other than your IEMs ?
 
If you still hear noise all of the time, I would think about that exchange. You can send it to JDS and I think that they will take care of you. I sent my C5D in for something I messed up. I sent it on Monday and had it back on Friday of the same week. Hard to beat going to a local store and just walking out with a new unit though.

You're right, I am referring to the continues hiss present in the background, not the digital control tracking click which I also hear. 
 
I disconnected the source in my testing. 
 
After jeseaber's response, I'm pretty sure it's normal since I'm using more sensitive iem, 124db/mW.
 
However, it's strange that at max volume, I can detect hiss even with other non sensitive headphones. 
 
Are you hearing any hiss out max volume with no music sound playing with your RE 400? 
 
Having said that, I pretty sure it's normal as jesaber said, for the hiss to increase proportionally with volume. Hiss has always been present with all the portable amp I've owned and tried when set to near max volume. 
 
I'm just going to enjoy my new c5 and stop worrying. 

 

[FiJAAS]

I wonder if you are not referring to something other than what Fungus is hearing. I thought that he was talking about background "hiss"/noise all of the time. Maybe I am the one not getting it though.
I just turned my C5D on and plugged in my RE 400s. No source connected as this will isolate any noise to only coming from the C5D.
I ran the volume to max and back to minimum. While the digital control is tracking I can hear a low sort of clicking sound. It is almost like static, keeping time with the digital volume steps...not what I would call hiss... or any kind of continuous background noise of any kind.

At either extreme of the volume control or anywhere in the middle, once I stopped changing the volume level, there is no detectable noise. The thing, with those IEMs and my ears, had a pitch black noise free background.

Fungus, have you tried to see if your noise is present when the C5 is not connected to anything other than your IEMs ?

If you still hear noise all of the time, I would think about that exchange. You can send it to JDS and I think that they will take care of you. I sent my C5D in for something I messed up. I sent it on Monday and had it back on Friday of the same week. Hard to beat going to a local store and just walking out with a new unit though.

It could be static instead of hiss, but either way it's a slight noise that's not bothersome. Nothing extreme. I'm not complaining, I love this amp.

 

[dbdynsty25]

  I just got my C5D and can't get it to work through my LG G3. It's plug and play with the micro-mini USB through my Galaxy Tab, and both are running 4.4.2 (G3 is stock, Tab is a custom ROM, not CM). The only troubleshooting I could think to do was to enable USB debugging and reboot, but that didn't solve it, it still plays through the phone speaker instead of through the C5D.
 
Also, when playing through my Tab, after a couple songs (~8-10 minutes) I will start to hear a light pop/crackle that gets progressively worse. If I pause it, wait a moment, then resume playback it goes away, and I've noticed it on both gain settings and with or without bass boost. Power indicator is solid green, and is set to BAT... wondering if it may be a lemon?

 
Mine works perfectly w/ my G3.  Just be sure the switch on the back is set to Battery prior to turning it on AFTER connecting it to the G3.  What variant do you have?  Mines the At&t version. 

 

[gauchotodd]

Mine works perfectly w/ my G3.  Just be sure the switch on the back is set to Battery prior to turning it on AFTER connecting it to the G3.  What variant do you have?  Mines the At&t version. 

Mine is the T-Mo variant, and I've tried every combination of switches on the thing with no luck.