[Brooko]

  @Brooko You can calculate the power at 300 Ohms by taking the V_p-p max divide that by 2, multiply by 0.707, then square that, then divide by 300.
(V_p-p max/2 * 0.707)² / 300
or
P = VRMS² / 300

 
Thanks Stan - then the E11K would be putting 31 mW into 300 ohm 
 
Vs HPA-50's 65mw per channel.
 
E12 would be ~ 93mW for 300 ohm.

 

[StanD]

   
Thanks Stan - then the E11K would be putting 31 mW into 300 ohm 
 
Vs HPA-50's 65mw per channel.
 
E12 would be ~ 93mW for 300 ohm.

Don't have the specs for the HPA-50's but you got the FiiO's correctly.
Voltage is usually the limiting factor on high impedance headphones as not much current is needed to achieve the same wattage as on low impedance cans.

 

[rigodeni]

Ugh, what I didn't want to hear. I got my hd 600 yestetday and while I have plenty of home amp I have an E11 (original not k ) on the way cause I got it for $50. Thought it would work for mobile

There's alot of variables here, and your results could vary. But the E11 should work OK. For me it's comfortable at about 80-90% volume (high gain), and I do go 100% on quieter tracks or noisier places. But I might like it louder than you. Also the ambient noise where you listen will affect how much volume you need, specially with an open headphone like the HD 600. Not all sources have the same output power also. On my Moto X I need 90-100% volume, but on my iPod Classic it's closer to 75-85%. My brother in-law's iPhone 6 Plus can actually drive the HD 600 pretty well without any amp (around 75% for me).
 
Although the E11 can be suitable for some, because there are so many variables I do generally suggest something more powerful. This will provide more headroom for quieter tracks, weaker sources, noisy environments, and deft people . And you never know if one day you will own a harder to drive headphone. The HD 600 is by no means the most difficult to drive. I own a pair of Beyerdynamic DT 770 Pro 250Ohm but they seem to require 10-20% more power than my HD 600 in my setup. Imagine the DT 880 600Ohm (which I plan to own at some point).

 

[Phishin Phool]

I just saw a review where they actually recommended three different amps for the 600 - entry level , mid level and upper level the e11 was the entry level one so it may be fine. Just in case I have committed to a combo DAC/AMP on massdrop if it hits the lowest level which it probably will. Since it also has opti and coax  outputs in the dac section I can use it as a usb-->toslink opti or s/pdif coax converter if I want and the headphone output is 120mw at 300ohms so it should certainly work.

 

[adtrance]

  I just saw a review where they actually recommended three different amps for the 600 - entry level , mid level and upper level the e11 was the entry level one so it may be fine. Just in case I have committed to a combo DAC/AMP on massdrop if it hits the lowest level which it probably will. Since it also has opti and coax  outputs in the dac section I can use it as a usb-->toslink opti or s/pdif coax converter if I want and the headphone output is 120mw at 300ohms so it should certainly work.

 
Just out of curiosity, which three amps were mentioned in this review you read?

 

[Phishin Phool]

They were the  Fiio E11 (budget)
Beyerdynamic  a200p (portable + mid level)
and Bottlehead crack for upper end.

 

[StanD]

  They were the  Fiio E11 (budget)
Beyerdynamic  a200p (portable + mid level)
and Bottlehead crack for upper end.

I'd kick up the budget, just a notch to the FiiO E12. If you're looking for the E11, the E11K is the newer model.
 
At the high end, I could think of many things. A Schiit Valhalla 2 comes to mind. The Asgard 2 does a fine job of it and is versatile. I don't think anyone has to spend thousands of dollars to amp the HD600 or just about any other headphones.

 

[Tuco1965]

The 600s sound very nice on my Lyr.

 

[bikerboy94]

I use E12 with my 600s works just fine. Prob will add higher end desktop system at some pint but no hurry.

 

[Phishin Phool]

I ordered the e11 regular (I read several spots the bass was better and the ergonomics of having the input/oupt on the same end as the volume knob was better than the k version and the volume knob was better with less channel imbalance at low levels). It was $50 delivered NIB. If I don't like it I will give it to a niece or nephew. I may also order the musiland monitor O2 US Dragon dac/amp combo as mentioned. It has gotten very good reviews and like noted has 120mw at 300 ohms and is either usb or external powered.  Inputs - usb, opti, coax, and one other as well as opti and coax out for transcoding from USB if desired and handles up to 32/382 so for less than $100 it should work as well. Found it much cheaper on aliexpress than the current lowest massdrop price so can get it from there If I want.  Either one would be for occasional travel listening - work, hotel, vacation etc. 

 

[Phishin Phool]

At the meet I was at I heard the 600 on a lyr and a Senn hdva amp. Both were stellar. Currently I am using a Garage1217 Project Sunrise and Music Hall 25.3 whic sound awesome as well. Both are better than the headphone out of my Pioneer Elite Sc-82 which is good but not great.

 

[yangian]

To be honest, I really wonder how much extent can fiio e12 drive 600? Is there anyon can give some comments?
Say, If a >$1000 amplifier fully drived 600, how much e12 can do? 50%, 60%, 40% of a fully driven?
Thanks!

 

[StanD]

  At the meet I was at I heard the 600 on a lyr and a Senn hdva amp. Both were stellar. Currently I am using a Garage1217 Project Sunrise and Music Hall 25.3 whic sound awesome as well. Both are better than the headphone out of my Pioneer Elite Sc-82 which is good but not great.

A mere 200mW will take a HD600 to 120dBSPL. One doesn't need high wattage amps for the HD600 to excel.

 

[bikerboy94]

  To be honest, I really wonder how much extent can fiio e12 drive 600? Is there anyon can give some comments?
Say, If a >$1000 amplifier fully drived 600, how much e12 can do? 50%, 60%, 40% of a fully driven?
Thanks!

What do you mean by fully drive. If you mean loudness. Louder than you should with out ear damage. I never get more than 1/3 of the volume control. Even my E6 will get to unsafe levels. Sound quality won't be the same as a high price amp but its very good.

 

[StanD]

 
What do you mean by fully drive. If you mean loudness. Louder than you should with out ear damage. I never get more than 1/3 of the volume control. Even my E6 will get to unsafe levels. Sound quality won't be the same as a high price amp but its very good.

Most decent amps have distortion levels far below our ability to perceive. One thing to look out for is transient distortion on peaks. This is rarely tested for or revealed to us. For most headphones and amps, IMO this bit about scaling is highly overrated.