[preproman]

Does any one know why the EF-6 has only unbalanced inputs but yet has a balanced output.  So in fact what your getting is an unbalanced signal going to a balanced connection?  What's the point in that?

 

[Iron_Dreamer]

Quote:

Does any one know why the EF-6 has only unbalanced inputs but yet has a balanced output.  So in fact what your getting is an unbalanced signal going to a balanced connection?  What's the point in that?

It is not a balanced output.  The EF-6 is not a balanced amp.  It is a 4-pin XLR connector for ease of use with the HE-6's standard cable, so that no adapter is necessary.  It drives the headphones unbalanced from the 4-pin XLR, and extremely well I might add.  I will be posting a full review of the EF-6 shortly.

 

[Tetsuma]

It almost looks stylish/pretty. Great effort for the price!

 

[Iron_Dreamer]

Here is the review I referenced earlier  (In short, if you have an HE-6, you NEED an EF-6): http://www.head-fi.org/t/593646/review-hifiman-he-6-ef-6-an-elite-headphone-system-under-one-roof#post_8108323

 

[nigeljames]

Or the Audio-gd Master-6 that I have ordered

 
Nice review by the way.

 

[saisunil]

Is it discrete or or chip based amp like EF-5 ...
 
Thanks

 

[Iron_Dreamer]

It has seperate, fully discrete, class-A output stages for each channel.  The closest existing headphone amps in topology are the Dynahi and Beta22, which are DIY-only.

 

[jtaylor991]

I don't know anything about Classes (Class A etc) but the Darkvoice 337 is a tube amp that has discrete amps for each channel, and dual volume knobs which I felt made the imaging un natural like I was controlling it but I wanted it the way the artist intended (and fiddling with them to make things balanced in both ears like I naturally would want got very annoying) so I sold it. I downgraded (price wise) to an Audio-gd Compass with my 650s and enjoyed it much more.

 

[Iron_Dreamer]

Quote:

I don't know anything about Classes (Class A etc) but the Darkvoice 337 is a tube amp that has discrete amps for each channel, and dual volume knobs which I felt made the imaging un natural like I was controlling it but I wanted it the way the artist intended (and fiddling with them to make things balanced in both ears like I naturally would want got very annoying) so I sold it. I downgraded (price wise) to an Audio-gd Compass with my 650s and enjoyed it much more.

The Compass is a much less powerful and sophisticated amplifier than the EF-6.  While the Compass might drive the HD650, it doesn't appear to have the power to drive an inefficient headphone like the HE-6, or AKG K1000, as the EF-6 can.

 

[jtaylor991]

Oh I know that for sure, just mentioning another separately amped channels type of amp. Someday I hope to own this combo. After I read your review on EF-6 and HE-6 I was HOOKED! But I saw others disappointed by what they heard at CES but it's not like I'd have the money anytime soon anyway. I might want a sidegrade from my 650s with my current setup. HE-400s?
 
Quote:

The Compass is a much less powerful and sophisticated amplifier than the EF-6.  While the Compass might drive the HD650, it doesn't appear to have the power to drive an inefficient headphone like the HE-6, or AKG K1000, as the EF-6 can.

 

 

[Benjamin6264]

How many steps does the attenuator have?

 

[Iron_Dreamer]

24 steps

 

[munz]

i've  order this amplifier but its keep delaying  with so many excuses  ...now almost one month.  even the its ready stock...

 

[estreeter]

Quote:

Does any one know why the EF-6 has only unbalanced inputs but yet has a balanced output.  So in fact what your getting is an unbalanced signal going to a balanced connection?  What's the point in that?

 
Ignoring the EF6 for a moment - your question was answered below - I would draw your attention to this from Donald North on the design of his Sonett tube amp. This has little to do with the EF6, but your question seems to crop up all over the net whenever someone sees XLR connections on a single-ended amp. 
 
 

[size=x-small]Some comments about balanced headphone drive[/size] [size=x-small]I am frequently asked why the balanced output version does not include balanced inputs. This is because balanced inputs are not necessary to provide balanced headphone drive. Being a single ended amplifier, all it needs for input is a single ended (unbalanced) signal. The Sonett operates single ended triode with transformer loading the plate of the 6H30 amplification tube. The secondary windings on the output transformers are center tapped (and grounded for safety), thereby providing a true, differential, balanced output. Thus, you get balanced drive without the complexity from additional balanced input circuitry or input transformers. Again, the simpler - the better.[/size]

 

[.Sup]

Quote:

 
Ignoring the EF6 for a moment - your question was answered below - I would draw your attention to this from Donald North on the design of his Sonett tube amp. This has little to do with the EF6, but your question seems to crop up all over the net whenever someone sees XLR connections on a single-ended amp. 
 
 

[size=x-small]Some comments about balanced headphone drive[/size] [size=x-small]I am frequently asked why the balanced output version does not include balanced inputs. This is because balanced inputs are not necessary to provide balanced headphone drive. Being a single ended amplifier, all it needs for input is a single ended (unbalanced) signal. The Sonett operates single ended triode with transformer loading the plate of the 6H30 amplification tube. The secondary windings on the output transformers are center tapped (and grounded for safety), thereby providing a true, differential, balanced output. Thus, you get balanced drive without the complexity from additional balanced input circuitry or input transformers. Again, the simpler - the better.[/size]

I'm no audio expert and theoretically "the simpler the better" sounds reasonable but Audio GD for example makes super complicated devices yet they sound amazing.