fmzip said:

What are you using for a DAC Reddog?

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I am using a old school pioneer Reciever that has a 192/24bit dac. I hope to get the Gungnir dac next year. Although the irrational audiophile beast within me demands I save up for the Yggdrasil lol.

Reasessment of the Alpha Dogs, I really like them them but they do need some serious EQ adjustments to my ears.
 
Here's my curve for Flamenco Sketches, outstanding!
 
Whoever said they were  bright, not to my ears particularly with Jazz & Samba
 
 

fmzip said:

  Reasessment of the Alpha Dogs, I really like them them but they do need some serious EQ adjustments to my ears.
 
Here's my curve for Flamenco Sketches, outstanding!
 
Whoever said they were  bright, not to my ears particularly with Jazz & Samba
 
 

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Wow... that is quite an EQ

Hi All,
 
I'm new to this thread as I'm considering a Mjolnir to drive my LCD-X and XC.  I bought the Senn HDVA600 and HD800, hoping the amp would also drive the Audez'e cans.  Well, it won't, so now I'm looking at Schiit.
 
I started reading this thread at page 1.  
 
The interesting part - observing those of you who pre-ordered the Mjolnir as early adopters and, from your current profiles who still have the amp to this day.  That's fun.
 
So to sum it up, and will you please come back - how does the Mjolnir do at driving the LCD-X/XC?  How about at driving two pair of Audez'e cans at the same time?
 
All the Best -
RCBinTN

During a brief listen of the HDVA600, a while ago, i felt it was too thin but airy, and a bit on the dry side. This was as i say after only a brief listen.
 
The Mjolinir (which i have for about six months now) is punchy, and full bodied with excellent detail, although it might sound a bit grainy at times.
 
I can't remember if the HDVA600 lacked power and control, but the Mjolnir certainly doesn't.
 
As far as driving two headphones, i drive sometimes the HD800 (Anax II mod) together with HiFiMan HE-500 or Fostex T50rp (modded) and there is no lack in power for either phones.
 
I haven't tested the LCD's you mention though, but i suppose it is no problem whatsoever for the Mjolnir. 

rcbintn said:

 
 
I'm new to this thread as I'm considering a Mjolnir to drive my LCD-X and XC.  

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I've just moved from the Mjolnir to the Rag for my LCD-X.  It is a big step up, potentially in part since the output impedance of the Mjolnir, 1.5 ohm, is just too high for the LCD-X with its impedance of only 20 Ohm.  I know, recommending a more than twice as expensive amp isn't all that useful/informative.  But I do suspect that the Mjolnir output impedance may be problematic.  

stefanjk said:

  ............... It is a big step up, potentially in part since the output impedance of the Mjolnir, 1.5 ohm, is just too high for the LCD-X with its impedance of only 20 Ohm.  I know, recommending a more than twice as expensive amp isn't all that useful/informative...................................  

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Stefan,
 
Glad you are enjoying your Ragnarok.  However, I don't understand the linking of the output impedance of the Mjolnir to poorer performance of the LCD-X.  The Audeze are quite flat in their impedance vs. frequency, so 1.5 ohms should have almost no effect on sound quality or frequency response.  Please explain.  Thanks!

wilcox said:

   
Stefan,
 
Glad you are enjoying your Ragnarok.  However, I don't understand the linking of the output impedance of the Mjolnir to poorer performance of the LCD-X.  The Audeze are quite flat in their impedance vs. frequency, so 1.5 ohms should have almost no effect on sound quality or frequency response.  Please explain.  Thanks!

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I'm no EE and new to audio, so I may be mistaken, but my understanding that frequency dependent HF impedance  and hence equalization problems isn't the only way output affects sound.  Additionally, low damping ratios also lead to lack of bass control and 'muddy bass'.  I do think I hear that in the difference between the Rag and the Mjolnir...although it could be due to something else, the audible difference it there.    BTW, Purrin makes the same claim elsewhere, both for what you can hear and the cause, so I may be too influenced by that (but do blame him, if this is wrong about the cause). 

One way to think of the dampening factor ratio is the amount of 'direct control' the amp has on the driver in terms of over/under shoot along with the 'momentum' that the driver has built up (especially in the bass), and the amps ability to negate it.
 
Dampening factor is of course is a 'design criteria' and can be 'taken into account' in other ways, and sometimes by the design of the headphone driver itself, (which seems to be the case in our 800's).  And The Rok's output impedance of ≤ 0.1Ω (as compared to < 1.5Ω for the Mojo amp) while impressive in and of themselves, means it should be able to control (and in some cases it may be over control) the driver all the more.
 
But my observations of the pairing of The Rok and the 800's and the resultant impressive bass response, is that the matched volume control and the cpu monitored and controlled operating parameters of the circlotron circuit, specifically the bias and controlling the near dc FR of the amp, are the responsible major factors.  I of course could be wrong, but these 2 design criteria, when tweaked, DO result in impressive bass response, all other things being equal.
 
It is also of interest that there are no 'DC blocking' caps nor coils in the output path, due to the control the cpu has in terms of the DC control of the outputs.  Which means the driver and the active ouput devices are 'optimally' coupled, which can make for stupendous bass.
 
To take this further, this can be pointed at by this 'The Rok' spec.
Frequency Response: 20Hz-20KHz, -0.1dB, 2Hz-180KHz, -3dB  (emphasis mine)
This power bandwidth spec is quite impressive for a power amp.
The Mojo amp has a similar low frequency response spec.
 
 
JJ
 
 
Quote:

stefanjk said:

  I'm no EE and new to audio, so I may be mistaken, but my understanding that frequency dependent HF impedance  and hence equalization problems isn't the only way output affects sound.  Additionally, low damping ratios also lead to lack of bass control and 'muddy bass'.  I do think I hear that in the difference between the Rag and the Mjolnir...although it could be due to something else, the audible difference it there.    BTW, Purrin makes the same claim elsewhere, both for what you can hear and the cause, so I may be too influenced by that (but do blame him, if this is wrong about the cause). 

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Thanks, all, for your information.
 
The HDVA doesn't lack power.  It drives the HD800 very well from the Uber Bifrost (unbalanced) feed from a Macbook pro.  Volume dot at 10:00 is plenty of dB.
 
The HDVA also drives the LCD-X to loud levels, but the sound quality is poor.  Everything sounds muddy (even the treble).  I was suspecting this may be caused by the output impedance of the HDVA which is 16 ohms.  In comparison, my Asgard 2 with output impedance of <2 ohms can drive the X with clear sound quality.
 
The X specs recommend 1-4W of input power.  The Asgard delivers 1W into 32 ohms.  The Mjolnir delivers 8W into 32 ohms.  Both these amps have output impedance of 1.5-2.0 ohms.  My conclusion from reading these specs is the Mjolnir should drive the X more fully with similar sound quality.  Does this seem correct ?
 
I agree the Rag is completely different with 15W into 32 ohms and only 0.03 ohms of output impedance.
 
Thanks -
RCB

You will have no problem driving the LCD-X with Mjolnir neither clarity wise nor power wise.
 
It will be (far) superior in sound quality than the Asgard 2.
 
Impedance variations leading to under damping or over damping (as opposed to critical damping) are not in the region of a few ohms that you describe as the difference between the amps you use, so this is not the reason for your findings concerning the sound quality of the HDVA.
 
I suspect something wrong with the HDVA.

I own this combination (Mj +X & XC). Very Nice pairing, Good synergy.

purrin said:

   
I can't make up my mind if I want to sell my BA or not. If I do, I will need a low cost high performance replacement. (I mostly listen to my electrostatics now.) Also, a solid-state reference quality amp is always nice to have on hand for my measurements and subjective impressions of the plethora of overpriced crappy headphones which the big companies seem to be churning out these days.
 
It also matters because I know for a fact that there a lot of lurkers who trust my opinion (I'm sure there are also quite a few who think I'm full of crap), mainly because I'm not afraid to say that a lot the stuff which tends to be highlighted on HF is crap, so if I'm tempted to buy something myself, that may actually mean something to someone who's seriously considering the Mjolnir.

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You are right.
Much of it is crap, but not your posts, IMO.
You work mainly on facts, not opinions.  You are very careful with statements of your conclusions, and for that I, at least for one, thank you.
Don't think the objectivity doesn't go un-noticed.
 
Just my opinion, Purrin.
Regards,
Dick Bailey

rcbintn said:

  Thanks, all, for your information.
 
The HDVA doesn't lack power.  It drives the HD800 very well from the Uber Bifrost (unbalanced) feed from a Macbook pro.  Volume dot at 10:00 is plenty of dB.
 
The HDVA also drives the LCD-X to loud levels, but the sound quality is poor.  Everything sounds muddy (even the treble).  I was suspecting this may be caused by the output impedance of the HDVA which is 16 ohms.  In comparison, my Asgard 2 with output impedance of <2 ohms can drive the X with clear sound quality.
 
The X specs recommend 1-4W of input power.  The Asgard delivers 1W into 32 ohms.  The Mjolnir delivers 8W into 32 ohms.  Both these amps have output impedance of 1.5-2.0 ohms.  My conclusion from reading these specs is the Mjolnir should drive the X more fully with similar sound quality.  Does this seem correct ?
 
I agree the Rag is completely different with 15W into 32 ohms and only 0.03 ohms of output impedance.
 
Thanks -
RCB

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Output impedance really shouldn't matter, what will matter is the power delivered at a specified impedance. 
 
I think the biggest difference between the Asgard and Mjolnir is in the tuning. The Asgard is tuned a bit warmer, but the Mjolnir is a really uniquely aggressive sounding amplifier. The really tight bass is a great pairing for the Audeze headphones. 

Sound very nice when paired with the 650's! An odd but awesome combo!