My impressions of HE-6 vs HD800 vs Stax SR-007

[AudioCats]

I think what is needed is "current capability", i.e. how easily can the amp dump current so it can keep up with the transient (after all, in a dynamic or ortho it is current that makes the sound). Has to do with the output impedance of amp, and, usually, the bigger the amp the lower the output impedance, and since the amp's usually don't show output impedance spec on the decal, we use the amp's wattage to "gusstimate" the output impedance.
 
Here is my guesstimate: per my experience, I want the amp to be able to safely dump at least 20x the I-max to a safe load ( I-max is the current used by the phone at a loud max volume), so I can make sure the amp is not stressed at peak transients. In the HE6's case, I will use 1W as the desired max output, the I-max is about 1/7 amp. Times 20 it will be about 3 amp. So I want the amp to be able to safely dump 3 amp all day long. To use a amp that is rated to drive 4R, I will need 35W per channel. not that the phone will use the 3 amp current, but the amp must be able to do it if needed to.... Just a ball-park guess.
 
 
 
Quote:

It's the same thing... Divide power (watts) by resistance (ohms), take the square root of the result, and you get the current (amperes). Providing current and power go hand-in-hand. If an amplifier can't drive the amperes, it won't drive the watts either and vice versa.
 
I see only 4 potential explanations:
 

• The HE-6 sensitivity isn't really 83.5dB at 50Ohm and 1mW.
• The HE-6 impedance isn't flat, and it goes under 50Ohm.
• Amps with a rating of 1W that we tried don't actually perform well at power levels anywhere near that.
• I'm missing some chunk of physics here.

 
  

 

[visualguy]

Quote:

The Gilmore Lite outputs the max 1W at 32 Ohms: http://gilmore2.chem.northwestern.edu/projects/showfile.php?file=gilmore3_prj.htm
 
I find your impressions interesting btw - and encouraging for the OII/KGSS combo. Just goes to show it doesn't necessarily take a Blue Hawaii for the OII to beat out the HE-6 and HD800.

Thanks - I had already looked at Kevin Gilmore's write-up on the Dynalo, but I wasn't sure the specs he talks about apply to the GLite since Justin may have customized the Dynalo, and also I'm not sure how the power supply affects things (I have the big wall wart).
 
I never listened to the Blue Hawaii, but I'm very happy with the way the KGSS drives the OII, and that combo beats the HE-6 and HD800. Some people say the BHSE amp improves the bass when compared to the KGSS, but other than that I haven't seen much exaplanation of how the BHSE is better than the KGSS.
 
I hope to get a chance to listen to the BHSE some day, but amps with tubes just aren't my thing. Too much hassle and heat. If I remember correctly, the BHSE power consumption is somewhere around 150W.

 

[visualguy]

Quote:

I think what is needed is "current capability", i.e. how easily can the amp dump current so it can keep up with the transient (after all, in a dynamic or ortho it is current that makes the sound). Has to do with the output impedance of amp, and, usually, the bigger the amp the lower the output impedance, and since the amp's usually don't show output impedance spec on the decal, we use the amp's wattage to "gusstimate" the output impedance.
 
Here is my guesstimate: per my experience, I want the amp to be able to safely dump at least 20x the I-max to a safe load ( I-max is the current used by the phone at a loud max volume), so I can make sure the amp is not stressed at peak transients. In the HE6's case, I will use 1W as the desired max output, the I-max is about 1/7 amp. Times 20 it will be about 3 amp. So I want the amp to be able to safely dump 3 amp all day long. To use a amp that is rated to drive 4R, I will need 35W per channel. not that the phone will use the 3 amp current, but the amp must be able to do it if needed to.... Just a ball-park guess.
 
 
 
Quote:

 

I can see why you might want two times I-max just to make sure you don't push the amp to its limit, but why 20 times? Seems like way too much headroom and overkill... Even 35W into 50Ohm is less than 1A, not to mention that it's over 40V which would probably fry the handphones!
 
The output impedance of the DAC1 headphones amp is under 0.11Ohm.

 

[moodyrn]

No it want fry your headphones(others, sure but not these). There's one person who used a pair of 300 watt monoblocks, and claims to have the volume knob set on 12:00. I can't remember who it was. I have used mine on a 140 watt receiver(one of the few receivers to put out it's rated output) and it takes just as much on the volume knob to get them to decent levels as it takes for my psb floorstanders. I'm not saying you should use 150-300 watt speaker amp, but some have used high powered speaker amps with good success, but you do need around 6 watts at 50ohm to really do them justice. I'm basing this on experience and not any technical info. I'll leave it up to the experts like AudioCats to explain why that is. I've learn long ago not to rely on technical data. IME it had little to do with sound and real world performance.

 

[visualguy]

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No it want fry your headphones(others, sure but not these). There's one person who used a pair of 300 watt monoblocks, and claims to have the volume knob set on 12:00. I can't remember who it was. I have used mine on a 140 watt receiver(one of the few receivers to put out it's rated output) and it takes just as much on the volume knob to get them to decent levels as it takes for my psb floorstanders. I'm not saying you should use 150-300 watt speaker amp, but some have used high powered speaker amps with good success, but you do need around 6 watts at 50ohm to really do them justice. I'm basing this on experience and not any technical info. I'll leave it up to the experts like AudioCats to explain why that is. I've learn long ago not to rely on technical data. IME it had little to do with sound and real world performance.

Fair enough - real-world experience means the most. However, you have to realize that 6W into 50 ohms is over 17V which is way too much voltage and volume for headphones which supposedly produce 83.5dB of SPL at 0.224V. You're talking about over 120dB of SPL which would damage your hearing very quickly even if the headphones were capable of this kind of SPL. Either the headphone specs are wrong or you don't really need this kind of power. Something has to give...

 

[moodyrn]

I don't listen as loud as some, but I will say, I've never seen a headphone demand so much power. There were a lot of initial impressions that mirrored yours. There were people in the beginning recommending speaker amps, and they got ripped for it. But soon after more and more people tried them, and it eventually became to universal standard to use speaker amps with them. I never turned the volume to ear blasting levels, but when I listen to music with huge dynamic peaks, the power reserve is there. They flame out whenever I used high power headphone amps.

 

[AudioCats]

 
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Fair enough - real-world experience means the most. However, you have to realize that 6W into 50 ohms is over 17V which is way too much voltage and volume for headphones which supposedly produce 83.5dB of SPL at 0.224V. You're talking about over 120dB of SPL which would damage your hearing very quickly even if the headphones were capable of this kind of SPL. Either the headphone specs are wrong or you don't really need this kind of power. Something has to give...

we don't listen to that 120 dB all day long. But we might need 130dB when the kick drum goes boom or the cannon fires. We will detect any slacky-ness if the amp/phone can not do that.
 
you are mostly talking about steady-state #'s, while my guesstimate is for the dynamic/transient situation.
 
Or I can try another approach to guesstimate the amping need:
say, the loudest spike of the passage is 130dB, I want the amp to be able to handle it with ease, so I want it to be able to go at least 140 dB (probably not a lot of head-room there).
The sensitivity spec is 83 dB at 1mW, to make it simple I'd use 20dB per 10x, so 103 dB at 10mW, 123 dB at 100mW, and 143 dB at 1W (kind of agree with me using 1W as desired max peak output) . This is 1W on a 50R load. That requires about 7V RMS, while means a 12.5W speaker amp if it is 4R rated. Now if I want a little more head-room and add a few more dB's to the max peak power reserve, then I use 3dB per 2x, so 25~30W@4ohm is better...
 
By the way, I don't have a HE6, I have only listened to the prototype on a ZDT. All my guesstimates are "generalized speculations"

 

[Shahrose]

Nice comparison. Thanks for sharing.
 
I have to say though, both the HE-6 and *especially* the HD800 deserve a better source/amp driving them to make this comparison fair.

 

[visualguy]

Quote:

 


we don't listen to that 120 dB all day long. But we might need 130dB when the kick drum goes boom or the cannon fires. We will detect any slacky-ness if the amp/phone can not do that.
 
you are mostly talking about steady-state #'s, while my guesstimate is for the dynamic/transient situation.
 
Or I can try another approach to guesstimate the amping need:
say, the loudest spike of the passage is 130dB, I want the amp to be able to handle it with ease, so I want it to be able to go at least 140 dB (probably not a lot of head-room there).
The sensitivity spec is 83 dB at 1mW, to make it simple I'd use 20dB per 10x, so 103 dB at 10mW, 123 dB at 100mW, and 143 dB at 1W (kind of agree with me using 1W as desired max peak output) . This is 1W on a 50R load. That requires about 7V RMS, while means a 12.5W speaker amp if it is 4R rated. Now if I want a little more head-room and add a few more dB's to the max peak power reserve, then I use 3dB per 2x, so 25~30W@4ohm is better...
 
By the way, I don't have a HE6, I have only listened to the prototype on a ZDT. All my guesstimates are "generalized speculations"

I was estimating half a watt into 50 ohms, but I'm ok with your estimate of 1W into 50 ohms. The thing is that the DAC1 headphones amplifier can easily do that, and supposedly the Gilmore Lite can do that as well. Actually, there are plenty of headphones amps that can do that, so why are people insisting on speakers amps for these headphones?
 
By the way, how loud can the HE-6 play anyway? Many headphones can't even reach 120dB, not to mention the 130dB and 140dB that you mentioned (which I wouldn't want to be exposed to even for a few seconds.)

 

[visualguy]

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Nice comparison. Thanks for sharing.
 
I have to say though, both the HE-6 and *especially* the HD800 deserve a better source/amp driving them to make this comparison fair.

The DAC1 HDR is a top-notch source. I have other good sources like the Marantz SA-7S1 and the Bel Canto DAC2.5. The DAC1 is in the same league. Anyway, I'm using it as a source with all my headphones (including the SR-007), so it's a fair comparison in terms of source.
 
I'm going to try the HD800 and the HE-6 with higher-end amps (Beta 22 and GS-X), and I'll post my impressions.
 
So far, I haven't found amps to make as much difference as one would expect based on Head-Fi discussions. I used to own a Meier Opera and an M^3 in addition to my GLite and DAC1. The differences between the Opera, GLite, and DAC1 were very minor. The M^3 sounded a little different, but I can't say that it was better or worse (just somewhat colored I guess). Headphones (my old HD650 and SA5000) retained the same characteristics across all these amps.

 

[AudioCats]

Quote:

I don't see how this is compatible with the sensitivity of the HE-6 and fundamental electric laws.
 
The HE-6 produces 83.5dB at 1mW and it's 50Ohm, so if you feed it 0.224V you will get 83.5dB of SPL.
 
The DAC1 is capable of providing a current of 0.250A, which is 12.5V and 3.125W at 50Ohm. 12.5V gives you 35dB of gain compared to 0.224V, so with the DAC1 the HE-6 can play at 118.5dB with the full power that you get from Ohm's Law (3.125W).  
 
118.5dB is way higher than the volume that you need even for peaks. I would conclude based on the above that the DAC1 has enough power to drive the HE-6 to their full capabilities.
 
The 6W @ 50Ohm that you mentioned would produce 17.3V which would result in a gain of 37.8dB instead of the 35dB that you get with the DAC1, so if the amp was feeding that to the HE-6, they would play at 121.3dB instead of 118.5dB - completely irrelevant...
 
The reality is that even the 3.125W that the DAC1 can provide won't be used fully because the voltage (i.e. volume) would be too high based on the sensitivity of the HE-6 and the basic electric laws.
 
If someone can show that I'm missing something here, then I'd be very interested in hearing that.

Are you sure the Dac-1 can do 250mA on a 50R load? just because the output buffer can do 250mA without being damaged doesn't necessarily mean it can pump that much in to any load.

 

[visualguy]

Quote:

Are you sure the Dac-1 can do 250mA on a 50R load? just because the output buffer can do 250mA without being damaged doesn't necessarily mean it can pump that much in to any load.

True, it may not be able to pump 250mA into 50 ohms. However, the spec does mention that it can pump 1.25W into 60 ohms, so I don't think that 1W into 50 ohms would be a problem.

 

[coolcat]

From my expericence with my HE6 ,they really need power.
I don't know about the theories ,but the sound of HE6 really change,when you connect to the different amp. M3 can't drive HE6 properly,Beta22 is fine,My DIY Tube amp with 9 watt per chanel (connect with speaker post) is also fine,Cary SLI80 from my friend is even better and out of my 60 watt harmarkardon home amp ,they sound good.It's like the more power you give them the better sound you get.I hope you try them with the Home amp,It is not hard to make the adater to use with the home amp like you see in the picture in a post before.
I myself  havn't found the HD800 sound better than the HE6.They have pros and cons,even though I like the HE6 and I think they are better headphones than HD800,but it's up to your taste,some may find the HD800 is better than HE6.
 

 

[Towert7]

Quote:

I've been happy with my Stax SR-007 (Omega 2 mk1) and KGSS amp for over 3 years now. I used to have a few dynamic headphones and amps, but I sold all of my dynamic headphones and most of my amps when I started using the SR-007. There was just no point in keeping the dynamic stuff because the SR-007 was much better.
 
I recently decided to check out a couple of new headphones - the HE-6 and the HD800 to see if stats really have some competition now.

Very nice info visualguy. 
 
I made a similar comparison between the HD800 powered by my GS-1 and two stats, the Senn HE60 and Stax O2 Mk1 powered by my GES.
The O2 were significantly better for me than the HD800 by a huge margin.  The O2 edged out on the HE60 in the bass and smoothness department, so I kept the O2.  HE60 were still a great phone.
 
I'm curious to compare an LCD-2 to my O2 setup.  My hunch is that it will not be as good, but I won't know until I try it.

 

[InnerSpace]

 
Has anyone independently measured the HE-6's impedance?  It could be way lower than the quoted 50 ohms (or way higher, but that seems less likely) which would explain a lot.