[RCBinTN]

What OTHER headphones (besides the expected HD 800, HD 650, HD 600, and maybe HD 700) have you successfully used your HDVD 800 with?

With an output impedance carefully selected to be 43 ohms, it is high enough that it violates the rule of 1/8 recommended for headphone damping (headphone input impedance should be at least 8 x amp output impedance), except for headphones with 300 ohm + impedance.

Do you actually HEAR a degradation when you use the HDVD 800 with a lower impedance headphone, say a Grado, as compared to an amp with lower output impedance?

 
That's interesting, I hadn't heard about the 1/8 rule but it makes sense.
I tried driving my LCD-X (22 ohms) with the HDVA600, and the sound was terribly muddy.  Fooled around with the adjustable gain but it didn't make much difference.
I was not overly disappointed, however, as I bought the HDVA600 specifically to drive my HD800.
 
Enjoy the music!
RCBinTN

 

[ALRAINBOW]

The rule was not made for headphones , it's for speakers or anything with a crossover.
I own a head dac it's OTL at 1K ohm output imp. The he 800 and my lcd3 sound wonderful.
The output imp is for speakers and is based on counter emf mainly for woofers and is related to something called dampening effect. No headphone has enough of coil and or magnet to delvelop any or extremely little counter emf.
How ever it does has a profound effect on iems as they have crossovers and it greatly effects the high freq curves .
It more likely bad synergy for the lcds. You have and maybe not enough power to drive them well.
ES amps are otl and the headphones are also high imp but not as high as the output once they become electrified by the bios voltage. My phonitor is aslo relatively high output imp at I think 25 or so. My MyTek dac was 20 ohms until I lowered it to use with ciems. Some reviewers make claims of the rule. But I do one have not heard its effects.
And I not claiming you are wrong but things do not seem what they are sometimes .
Just my point of view
Also most amps like to add the resistance at the output for short protection. If they thiught it was effecting our sound would they. But it does mess with our iems.
Al

 

[ruthieandjohn]

The rule was not made for headphones , it's for speakers or anything with a crossover.
I own a head dac it's OTL at 1K ohm output imp. The he 800 and my lcd3 sound wonderful.
The output imp is for speakers and is based on counter emf mainly for woofers and is related to something called dampening effect. No headphone has enough of coil and or magnet to delvelop any or extremely little counter emf.
How ever it does has a profound effect on iems as they have crossovers and it greatly effects the high freq curves .
It more likely bad synergy for the lcds. You have and maybe not enough power to drive them well.
ES amps are otl and the headphones are also high imp but not as high as the output once they become electrified by the bios voltage. My phonitor is aslo relatively high output imp at I think 25 or so. My MyTek dac was 20 ohms until I lowered it to use with ciems. Some reviewers make claims of the rule. But I do one have not heard its effects.
And I not claiming you are wrong but things do not seem what they are sometimes .
Just my point of view
Also most amps like to add the resistance at the output for short protection. If they thiught it was effecting our sound would they. But it does mess with our iems.
Al

Here's a nice article by Jan Meier, quoted by Tyll Hertsens in his Inner Fidelity column, with explanatory notes by Tyll, about the interplay of amp output impedance and headphone input impedance.
 
http://www.innerfidelity.com/content/musings-headphone-amplifier-output-impedance

 

[ALRAINBOW]

I know the article and he is the guy to make the claims. I just feel there is other things at play and I do it hewr what he does. But I do respect what he says and is a nice guy . But even some of hisnrevoews I feel are off for me. We all hewr a little diffent . He feels the Lcds are fine , I find them dull and mid reseed . Who is right answer both of us. For me the lcd whole line is mid reseed and nice to listen to for hours and non fatiguing but not for a reference can.
I own the lcd3. And feel as I posted. Some love the Lcdx. I hate that can it just sounds odd to me.

 

[BrunoS72]

How did the 43 ohm impedance specification came about? Has Sennheiser published this data or it is forum lore?

 

[ALRAINBOW]

Not sure but it's 20 SE And double that in balnace mode

 

[RCBinTN]

I know the article and he is the guy to make the claims. I just feel there is other things at play and I do it hewr what he does. But I do respect what he says and is a nice guy . But even some of hisnrevoews I feel are off for me. We all hewr a little diffent . He feels the Lcds are fine , I find them dull and mid reseed . Who is right answer both of us. For me the lcd whole line is mid reseed and nice to listen to for hours and non fatiguing but not for a reference can.
I own the lcd3. And feel as I posted. Some love the Lcdx. I hate that can it just sounds odd to me.

Al - have you heard the LCD-XC?  It's a little different...

 

[ALRAINBOW]

No I have not. I do want to hear the new he1000 from hifiman. As I like the he6 very much

 

[kazsud]

The LCD-X and LCD-F sound fine (balanced) on the HDVA600 but sound better on the GSX mkii.

 

[ALRAINBOW]

And i am sure it does. My only point it's sysnergy not the claim of damping factor there is just no justice in it being true. What can be going on is other factors. There is many high output imp Amps they are loved
You would be surprised maybe even the one you just quoted. It's only with a iem with a crossover they it's imperative to be low very low. But as I say it's my subjective view not saying I am a god and know it all
Al

 

[ruthieandjohn]

I wonder how a damping factor applies to speakers but not to headphones (except IEMs with crossovers), since both are basically the same type of electromagnetic transducers.

 

[Cheebamaster]

Just bit the bullet and ordered the Sennheiser HDVA600, HD800, and Sennheiser upgraded balanced cables. For the DAC I went with the upgraded Bifrost from schiit. Does anyone have experience in pairing the Schiit Bifrost with the HDVA600? I didn't want to break the bank more than I already did, but would this be lacking in the DAC department or will it be perfect?

 

[ALRAINBOW]

It spoiled to all voice coil devices. But the coils I headphones are too tiny to crest any counter emf to effect dapining effect. And planers as in auduzze a do others have no voice coli it's the entire foils diafram so. No inductance at all. The inductance is what is counter emf. He entire concept is just not correct and why it's posted as such and has become legendary is just that a legend without merrit. Don't look at me as a wizard I am only pointing g out facts not myths
Google about it. And learn as I did. It's just wrong. But some make claims so it's real. It's like headphones wires making a difference it too is myth but strongly argued into a beleaf. I am sorry and not looking to be myth busters but it's just facts.

 

[ruthieandjohn]

It spoiled to all voice coil devices. But the coils I headphones are too tiny to crest any counter emf to effect dapining effect. And planers as in auduzze a do others have no voice coli it's the entire foils diafram so. No inductance at all. The inductance is what is counter emf. He entire concept is just not correct and why it's posted as such and has become legendary is just that a legend without merrit. Don't look at me as a wizard I am only pointing g out facts not myths
Google about it. And learn as I did. It's just wrong. But some make claims so it's real. It's like headphones wires making a difference it too is myth but strongly argued into a beleaf. I am sorry and not looking to be myth busters but it's just facts.

I'm just here to learn!  Your idea that it is a matter of scale (big coils vs. tiny coils) and type (with coils vs. without coils) makes sense. 
 
Getting there...
 

 

[ALRAINBOW]

I have an electrical engineering degree and do understand the stuff some say here
But audio does diverse from theory and does make as some sound changes that not always can be explained by theory. So I too read tykes words and I too become concerned until I tested my and many others headphones and measure there amps and rest the specs. Although it makes for good reasoning it's just not so. Not saying some do sound better on some Amps then others. The why is still Illusive in some cases. But for me and only me it's only when a crossover is envokved it becomes imperative
The why is complex but can be shown in theory and heard easily. Another odd thing but a fact is why some Iems buzz or hiss woth some amps until music plays.
I do understand a probable cause but the better sounding Amps do this and the ones that are silent are sometimes vailed.