[nudd]

   
 
At matching volume level I found both O2/ODAC and M8 sounded similar on a blind test listening with T1. But with sensitive iems, M8 sounded a bit grainier background. Most likely because it has a higher noise floor than O2.

 
M8 is known to hiss with sensitive IEMs and their fix is to drop gain by 6 dB. That drive the background noise to below audible levels at low gain apparently. And it costs $100 to get them to do it.

 

[headwhacker]

   
M8 is known to hiss with sensitive IEMs and their fix is to drop gain by 6 dB. That drive the background noise to below audible levels at low gain apparently. And it costs $100 to get them to do it.

 
I know, it was suppose to be a swiss army knife of DAC/Amp device as it was advertised and should handle iems to full-sized cans. The iem mod will also reduce the overall power output to half. So pick your poison 

 

[Heartsmart]

My choice is between hifi m8 and iDSD Micro. someone who has experience of both wanting to give their opinion?

 

[doctorjazz]

Can't answer the question on iDSD. I have been comparing it to the Geek Out Special Edition (have a 1K also, should compare at some point). It's close, each does some things better, the SE seems to flesh things out a bit more, the M8 has better control low end, depends what I'm listening to, early impression GO SE a bit more enjoyable, M8 a ton more flexible/functional. Just a short comparison yesterday, listen some more...

 

[kelvinwsy]

I am still waiting for my GO PULSE but have owned and sold he M8 LX, after I bought the iDSD MICRO. M8 usb driver and recognition by JRiver was unstable. SQ wise the m8 was a bit dry. The IDSD gas better highs . M8 does have better bass control with it 3 position switch but even on my H800, the iDSD XBass was ample bass boost.

 

[ai_enabled]

I have a pair of Fostex TH-600 headphones and can hear a little hiss even on lowest gain setting (with lowest output impedance), when I order M8 I was informed it will hiss a little only with IEM (without IEM-mod)...
 
Quote:

   
M8 is known to hiss with sensitive IEMs and their fix is to drop gain by 6 dB. That drive the background noise to below audible levels at low gain apparently. And it costs $100 to get them to do it.

That's frustrating, as many customers leaving not in US. In my case, I will need to pay ~30% of full M8 price to customs when receive item back from CEntrance.
Is there any DYI solutions for doing that? I bet is not harder than (de)soldering a few resistors. I don't care about the warranty as it expires soon anyway.

 

[NZheadcase]

  That's frustrating, as many customers leaving not in US. In my case, I will need to pay ~30% of full M8 price to customs when receive item back from CEntrance.
Is there any DYI solutions for doing that? I bet is not harder than (de)soldering a few resistors. I don't care about the warranty as it expires soon anyway.

 
I use my TH900s with the M8. In fact I have them on my head right now. It is strange as I don't hear any hiss at all. Does it do this with all your sources? Which input is most affected? 
 
I've experienced a bit of hissing before, but that was due to the old iPhone cable I used. Got a shorter one from monoprice. No hissing since then. 

 

[ai_enabled]

   
I use my TH900s with the M8. In fact I have them on my head right now. It is strange as I don't hear any hiss at all. Does it do this with all your sources? Which input is most affected? 
 
I've experienced a bit of hissing before, but that was due to the old iPhone cable I used. Got a shorter one from monoprice. No hissing since then. 

I've tried multiple sources: iPhone 3GS with 30-pin cable, iPad Air with lightning cable, PC with different USB cables, also MacBook Pro...
Also I've tried both single-ended outputs (my TH-600 isn't modified to use balanced output).
A little hissing is still present, it especially noticeable on middle volume (and nearly disappears on low and high volume). Changing gain to more high seems to not increase hissing.
And of course when I turn off the M8, hissing disappears - so I'm sure is not a problem with my ears .
Maybe my M8 has a bad quality volume pot? Also the headphones cracks/pops a little when I rotate volume pot.

 

[NZheadcase]

 
I've tried multiple sources: iPhone 3GS with 30-pin cable, iPad Air with lightning cable, PC with different USB cables, also MacBook Pro...
Also I've tried both single-ended outputs (my TH-600 isn't modified to use balanced output).
A little hissing is still present, it especially noticeable on middle volume (and nearly disappears on low and high volume). Changing gain to more high seems to not increase hissing.
And of course when I turn off the M8, hissing disappears - so I'm sure is not a problem with my ears .
Maybe my M8 has a bad quality volume pot? Also the headphones cracks/pops a little when I rotate volume pot.

 
If it crackles or pops when you adjust the pot, then, well. Have you contacted centrance? You probably don't need the mod, if the pot is to blame.  

 

[ButtUglyJeff]

I'm now suspecting the pot as well (not that I'm an electrical engineer).  My stock TH600 and now in its modded LA600 configuration never gave me any hiss either...

 

[kayza]

I've tried multiple sources: iPhone 3GS with 30-pin cable, iPad Air with lightning cable, PC with different USB cables, also MacBook Pro...
Also I've tried both single-ended outputs (my TH-600 isn't modified to use balanced output).
A little hissing is still present, it especially noticeable on middle volume (and nearly disappears on low and high volume). Changing gain to more high seems to not increase hissing.
And of course when I turn off the M8, hissing disappears - so I'm sure is not a problem with my ears .
Maybe my M8 has a bad quality volume pot? Also the headphones cracks/pops a little when I rotate volume pot.

I have TH600 and M8. Tonight I will be a/b'ing them with my new Momentum Wireless, so I'll let you know if I notice any hiss with my Fostex. My memory tells me I haven't experienced this.

 

[doctorjazz]

I'm now suspecting the pot as well (not that I'm an electrical engineer).  My stock TH600 and now in its modded LA600 configuration never gave me any hiss either...

It must be somewhere on this large thread, but could someone educate me on this mod?Thanks

 

[ai_enabled]

Quote:

I have TH600 and M8. Tonight I will be a/b'ing them with my new Momentum Wireless, so I'll let you know if I notice any hiss with my Fostex. My memory tells me I haven't experienced this.

Great!
I hear noise at medium volume pot position even when no source connected.
 

   
If it crackles or pops when you adjust the pot, then, well. Have you contacted centrance? You probably don't need the mod, if the pot is to blame.  

But as far as I know the cracking volume pot is a common issue with M8...
The main reason why I still not contact CEntrance, because I'm thought it's normal as with AKG K702 I didn't hear any hiss. It has higher impedance - 62 Ohm vs 25 Ohm - TH-600 very close to IEMs, so I'm thinking about the IEM-mod for M8... If kayza really can't heard any noise, I will contact with CEntrance.

 

[ButtUglyJeff]

It must be somewhere on this large thread, but could someone educate me on this mod?Thanks

 
Its often called the "IEM mod".  CEntrance just lowers the impedance/power to eliminate hiss for the more "delicate" phones that are prone to hiss with lots of power being thrown at them.  Something is lost for higher demanding headphones, so pick your poison.
 
If you're interested, just contact CEntrance.  I believe there is a small fee...

 

[doctorjazz]

It must be somewhere on this large thread, but could someone educate me on this mod?Thanks

Its often called the "IEM mod".  CEntrance just lowers the impedance/power to eliminate hiss for the more "delicate" phones that are prone to hiss with lots of power being thrown at them.  Something is lost for higher demanding headphones, so pick your poison.

If you're interested, just contact CEntrance.  I believe there is a small fee...

Thanks-does seem to go against what the original claim to fame of the M8 was...and now, there is a lower powered version, with more input options. Better to get that if you haven't already purchased an M8.