[XERO1]

The Asgard 2 will make close to 1W into the 70 Ohm impedance of the Z7.  
 
How is that not enough power for a 102 dB/mW sensitive headphone?

 

[takato14]

  The Asgard 2 will make close to 1W into the 70 Ohm impedance of the Z7.  
 
How is that not enough power for a 102 dB/mW sensitive headphone?

It's not that it's not enough. It's too much. The Asgard favors voltage over current, which is good for high impedance (250+ ohm) headphones. It's not quite so good for low impedance headphones, which will get too loud too early on the volume control, preventing you from getting as much current into the headphone as you could with a lower voltage design.
 
It's almost always better to put as much current into something as possible, as it generally increases driver control and transient response. This is why planar-magnetics like the HE-6 respond so well to speaker amps, which are designed around low impedance loads and thus push a huge amount of current by design.

 

[XERO1]

  It's not that it's not enough. It's too much. The Asgard favors voltage over current, which is good for high impedance (250+ ohm) headphones. It's not quite so good for low impedance headphones, which will get too loud too early on the volume control, preventing you from getting as much current into the headphone as you could with a lower voltage design.
 
It's almost always better to put as much current into something as possible, as it generally increases driver control and transient response. This is why planar-magnetics like the HE-6 respond so well to speaker amps, which are designed around low impedance loads and thus push a huge amount of current by design.

 
I don't want to get too deep into this rabbit hole, but are there any published specs or info that supports this?
 
Thanks.

 

[XERO1]

 
I just found this on the Bakoon HPA-21 amp page (which btw, has both a high-current and a high-voltage headphone output) and the link to the FirstWatt article answers my questions.
 
 
Quote:

  You mentioned that there is no difference between the HE6 and LCD-3 like there is for the HD800. The main reason for that is because of the flat impedance curve on planar magnetics which generally lead to the same response in either setting. However for dynamic drivers this changes because power is calculated with P=I²R instead of P=V²/R. In voltage mode the power drops with an increase in impedance whereas in current mode the power actually increases with impedance. A lot of this is covered in this article by Nelson Pass.
 
http://www.firstwatt.com/pdf/art_cs_amps.pdf
 
He argues that for single driver full range speakers a current mode amp makes a lot of sense. While there aren't too many speakers made like this, headphones are basically universally made this way.
 

 

[takato14]

   
I just found this on the Bakoon HPA-21 amp page (which btw, has both a high-current and a high-voltage headphone output) and the link to the FirstWatt article answers my questions.
 
 
Quote:

  You mentioned that there is no difference between the HE6 and LCD-3 like there is for the HD800. The main reason for that is because of the flat impedance curve on planar magnetics which generally lead to the same response in either setting. However for dynamic drivers this changes because power is calculated with P=I²R instead of P=V²/R. In voltage mode the power drops with an increase in impedance whereas in current mode the power actually increases with impedance. A lot of this is covered in this article by Nelson Pass.
 
http://www.firstwatt.com/pdf/art_cs_amps.pdf
 
He argues that for single driver full range speakers a current mode amp makes a lot of sense. While there aren't too many speakers made like this, headphones are basically universally made this way.
 

That is not related to what I was talking about in any way. That's talking about a specific amplifier topology that is (currently) very esoteric and nothing like the Asgard's design.
 
What I was talking about was amplifier/headphone matching. There is an ideal ratio of voltage to current for every headphone. Specifics for any particular headphone are very difficult to calculate, but the generalization is that low impedance requires a lot less voltage to push adequate volume levels than high impedance. For headphones that NEED a lot of voltage (HD600), the Asgard would be ideal, but for something like the Z7 it'll only cause excessive gain at low amplifier settings because the headphone doesn't need that much voltage to reach listening levels.
 
If you still don't believe me, I have had experience with the Asgard myself and low impedance headphones were not its strong suit. I could never get to 9 o'clock on the volume pot without reaching ear splitting levels on my low Z gear, and it sounded smeary and muddy. Couple that with the sound signature of the MDR-Z7 and you're probably going to have a very unpleasant, lo-fi experience.
 
Also, yes cspirou, Mjolnir would be a much better match for the Z7.

 

[cspirou]

The Asgard 2 will make close to 1W into the 70 Ohm impedance of the Z7.  

How is that not enough power for a 102 dB/mW sensitive headphone?

Asgard 2 has a gain switch for low gain mode at 1.5dB. The Z7 should be fine with the Asgard especially with 70 ohms.

The main reason to have low gain is because of transmitted noise. Higher gain means the noise gets amplified as well. At high voltages this isn't an issue because of the high signal above the noise. But for low voltages needed for sensitive headphones you start hearing the background noise.

The Z7 seems inherently balanced so I think the Mjolnir would be an ideal match (but more expensive).

 

[Robseth]

   
Hey Robseth, it's € 367 over here. The site is in Dutch but according to their info they do ship to certain countries within the EU. It states you have to contact them for the possibilities and costs.
 
You can try calling them at +31 184 417267 or use the contact form. I hope the form speaks for itself but if not, please let me know.
 

 

Thanks I wrote to them and until yesterday there was no answear. However yesterday I got an email from them and placed my order. Thanks again.

 

[Mink]

  Thanks I wrote to them and until yesterday there was no answear. However yesterday I got an email from them and placed my order. Thanks again.

Good to hear it worked out!

 

[Gandah]

  Seems that my "go to" setup for my Z7s is my AK100II....simply amazing together!

I've only tried the Z1 once on the GS-X m2 with diy balanced cable, I extremely liked it, what is your views with this combo ?
 
Right now the z1 is my next purchase

 

[grizzlybeast]

Does anyone here listen to the Z7 with dubstep, hip hop, and edm etc?
 
How do they fair?
 
Edit: I need to be patient for them to arrive here in a couple of days. NVM. I hope they are keepers.
 
I would however be very interested in a comparison of the z7 to the dx1000/2000 (hint hint @Oregonian ) specifically in clarity, soundstage, and dynamics. I have had the dx700 and thought it to be a bit too clouded with reverb but great otherwise. 

 

[purk]

  I've only tried the Z1 once on the GS-X m2 with diy balanced cable, I extremely liked it, what is your views with this combo ?
 
Right now the z1 is my next purchase

I am using the Z7 with a DIY silver cable out of the GS-X MK2 and like it a great deal too.  
 
My DIY silver upgraded cable (old headphile cable) help tighten the bass while improved the clarity as well as bettering the soundstage.  Originally, I'm not to keen on the Z7 as I found them to be too bass heavy, but now they are considerably better and I'll keep them.  For the price that Sony is charging for the their upgrade cable, I suggest to get a good upgraded silver cable instead.

 

[grizzlybeast]

Wrong thread!

 

[dweaver]

After a busy few days and only having time to use the Z5 I am having a listen to the Z7 tonight and the Z7 definitely has more of a WOW factor for me. When I listen to the Z5 I hear I hear an amazing IEM but I don't get lost in my music as easily. The Z7 on the other hand is just so much more immersive I slip into the music just enjoying what I hear almost instantly. I am glad I have both because I think they are an amazing well matched set of products that are so clearly cut from the same cloth so I get to have a similar experience when out and about as when at home. But the big boys do edge out their portable counterpart in immersion.

 

[XERO1]

  After a busy few days and only having time to use the Z5 I am having a listen to the Z7 tonight and the Z7 definitely has more of a WOW factor for me. When I listen to the Z5 I hear I hear an amazing IEM but I don't get lost in my music as easily. The Z7 on the other hand is just so much more immersive I slip into the music just enjoying what I hear almost instantly. I am glad I have both because I think they are an amazing well matched set of products that are so clearly cut from the same cloth so I get to have a similar experience when out and about as when at home. But the big boys do edge out their portable counterpart in immersion.

 
Thanks for that.  The Z7 will definitely be my next set of cans as soon as I have the extra cash for them.  I was this close to getting a pair but there was a killer flash sale on the Sennheiser HD 650's a couple weeks ago that was just too good to pass up.
 
But soon they will be mine!

 

 

[longboy]

   
Thanks for that.  The Z7 will definitely be my next set of cans as soon as I have the extra cash for them.  I was this close to getting a pair but there was a killer flash sale on the Sennheiser HD 650's a couple weeks ago that was just too good to pass up.
 
But soon they will be mine!

 

I know the feeling! I found a new NuForce DAC-9 for the MSRP of my old DAC-100. I couldn't resist, telling myself that, by the time that I get that kind of paper, again, the price of the Z7 may well have dropped. You never know.
BTW, NuForce has been bought out by a Chinese video-projector company. So, if there are other NuForce fans out there, it may pay them to watch for sales as older NuForce audio inventory gets dumped. I hope!