The Beyerdynamic DT880 Discussion thread

[wahsmoh]

I get 380mw @ 250 ohms with my Schiit Asgard 2

 

[devhen]

I've got 1100mW (& 16V) into 250 ohms with my G109 (default +8db gain) and still have to use almost all of the volume knob if I want to really rock out to some older, uncompressed, quietly recorded stuff, for example the original recordings of Talking Heads' Remain In Light or The Smiths' Meat Is Murder. With my DT770 Premium 600 ohm I occasionally actually run out of volume! (595mW & 18.9V into 600 ohms). Its enough for regular listening levels though. How quietly your music is recorded has a big effect on whether an amp will be enough for you but I guess a lot of people are probably just using gain normalizers.

 

[Chris J]

Because we love to "discuss" amp power,
I ran some numbers on the various impedances of DT880 to show current draw and voltage needed for various power levels.

 
32 Ohm Versions   (note: Innerfidelity specs the efficiency as 0.47 mW = 90 dB SPL)
1 mW = 179 mV, 5.6 mA
5 mW = 400 mV, 12.5 mA
10 mW = 565 mV, 17.6 mA
25 mW = 935 mV, 27.9 mA
100 mW = 1.79 V, 55.9 mA
 
250 Ohm versions   (note: Innerfidelity specs the efficiency as 0.38 mW = 90 dB SPL)
1 mW = 500 mV, 2.0 mA
5 mW = 1.12 V, 4.4 mA
10 mW = 1.58 V, 6.3 mA
25 mW = 2.5 V, 10.0 mA
100 mW = 5.0 V, 20.0 mA
 
600 Ohm versions   (note: Innerfidelity specs the efficiency as 0.43 mW = 90 dB SPL)
1 mW = 775 mV, 1.29 mA
5 mW = 1.73 V, 2.89 mA
10 mW = 2.45 V, 4.0 mA
25 mW = 3.87 V, 6.5 mA
100 mW = 7.74 V, 12.9 mA

 

[Argyris]

Here's where I get confused with all this stuff. If 0.38 mW produces 90 dB (which is reasonably loud), even assuming a non-linear increase in power requirements (set me straight here if I'm wrong), why wouldn't even the 30 mW output from the amp whose specs were listed earlier produce ear-shattering output? How about an amp that reached the maximum input of 100 mW for the DT880? Clearly I'm missing something here.

 

[Chris J]

  Here's where I get confused with all this stuff. If 0.38 mW produces 90 dB (which is reasonably loud), even assuming a non-linear increase in power requirements (set me straight here if I'm wrong), why wouldn't even the 30 mW output from the amp whose specs were listed earlier produce ear-shattering output? How about an amp that reached the maximum input of 100 mW for the DT880? Clearly I'm missing something here.

 
The missing ingredient is voltage gain!
When you turn the volume up and down on your headphone amp you are actually increasing and decreasing the amount of the voltage the amplifier is outputting.
If no headphone was plugged into the headphone amplifier, the amplifier would still output voltage.
Now, when you plug headphones into the headphone amplifier, the headphones will draw current from the headphone amplifier.
 
You're probably wondering where am I going with all this????
 
Take a look at the power tables I showed you in the previous post.
You'll notice that the 32 Ohm headphones take a lot less voltage at 1 mW than the 600 Ohm headphones.
Hence, you need to turn the volume control up more with 600 Ohm 'phones than with 32 Ohm 'phones.
If your source is not outputting enough voltage, or your headphone amplifier does not have enough gain (really voltage gain), then you might be turning the volume up on your headphone amplfier and wondering why am I not getting much volume out of this damn headphone amp?

 

[Chris J]

 
Here's where I get confused with all this stuff. If 0.38 mW produces 90 dB (which is reasonably loud), even assuming a non-linear increase in power requirements (set me straight here if I'm wrong), why wouldn't even the 30 mW output from the amp whose specs were listed earlier produce ear-shattering output? How about an amp that reached the maximum input of 100 mW for the DT880? Clearly I'm missing something here.

BTW, yes, apparent volume is rather non-linear.

10 mW is 10 dB louder than 1 mW

100 mW is 10 dB louder than 10 mW.

Subjectively, the average person will say that 10 dB louder sounds "about twice as loud".

So 10 mW is only "about twice as loud" as 1 mW.

 

[Chris J]

  sorry, truly, but one more amp related question... if I may
 
do you guys think an external amp will be necessary to use dt880-250ohm with below DAP:
 

Output Power 1	> 540 mW@16Ω	Output Impedance	<0.3Ω
Output Power2	> 270 mW@32Ω	Crosstalk	>75 dB@1KHz
Output Power3	> 30 mW@300Ω	THD+N	< 0.005%@1KHz
Frequency Response	10Hz~20KHz（+/-0.2)	MAX output voltage	> 8 Vp-p
SNR	> 105 dB (AUX IN)	MAX output current	> 250 mA

[td=colspan:4]X3[/td]

 
 
where can a girl learn what all those numbers mean? 

 
Try this link:
 
http://www.head-fi.org/a/headphone-impedance

 

[Makiah S]

if we are posting power specs
 
580mw into 600 ohms Balanced out NFB 10ES2 <3 

 

[Chris J]

I was actually trying to show the difference in voltage and current requirements for various impedance DT800 for the same power levels.

I was trying to explain that a low impedance phone needs less voltage than a high impedance phone for the same SPL (i.e power level).

In addition, a high impedance can needs more amplifier gain (i.e. voltage gain) than a low impedance set of cans.

Wee little amps like the E17 or E07 or X3 aren't really built or designed for driving high impedance 'phones like our 600 Ohm DT880 and their Beyer brothers.

Or we can go back to teliing really, really rotten jokes!

 

[Sonic Defender]

Hi Chris J, I could use some clarification here. I can't find the article, but I remember reading an article written by an electrical engineer (I think) and his point was that the ohms have very little to do with the volume level a given amp can drive a headphone to. He provided a technical explanation that demonstrated that it is the sensitivity that actually influences the real volume level you can achieve. I wish I had bookmarked the article (which I normally do), but because I didn't I can't confirm this.

 

[genclaymore]

With a Little Dot MK II to IV SE there are some fine tubes to be had for less than $10 a pair. The higher in class you go the more expensive it will be, on a nice $3500+ Woo, $200 to $300 a tube is not unreasonable.

What are those tubes that you were talking about that could be had less then 10 dollars a pair and how is their sound signature,so I can save the link for future reference.

 

[Chris J]

Hi Chris J, I could use some clarification here. I can't find the article, but I remember reading an article written by an electrical engineer (I think) and his point was that the ohms have very little to do with the volume level a given amp can drive a headphone to. He provided a technical explanation that demonstrated that it is the sensitivity that actually influences the real volume level you can achieve. I wish I had bookmarked the article (which I normally do), but because I didn't I can't confirm this.

Yes, you could argue that sensitivity is the number or spec that best describes the real volume level you'll get from a pair of cans.

Sensitivity is a number that states how much voltage a headphone needs to achieve a given SPL.
Less sensitive = needs more voltage, in English, ya gotta turn the volume UP more.
More sensitive = needs less voltage, in plain old English, ya don't gotta turn the volume up as much

In that table I posted a few posts ago (yesterday) you can see that a 600 Ohm Beyer needs more voltage than a 32 Ohm Beyer.
If we do some calulations and round everything off a bit, the 32, 250 and 600 Ohm versions all need approx. 1 mW to create an SPL of 96 dB.
Since the 600 Ohm 'phone needs 775 mV for apprx. 96 dB SPL we could say that it is a less sensitive 'phone (i.e. needs more voltage to achieve the same SPL or volume) than the 32 Ohm version which only needs 179 mV for the same SPL.

And if you compare an AKG Q701 to a Beyer DT800/600 we'll see that the Q701 is a more sensitive 'phone.
For the DT880.......775 mV gets us an SPL of approx. 96 dB. (BTW this is the manufacturer's spec)
The Q701...............1000 mV gets us a lot more volume: 105 dB. (this is the manufacturer's spec) so for a little more voltage, we get a lot more volume.
And you can ignore the impedance!

Make sense? I hope?

 

[TrollDragon]

 
What are those tubes that you were talking about that could be had less then 10 dollars a pair and how is their sound signature,so I can save the link for future reference.

Here is the table from the Little Dot Tube Rolling thread, most of the tubes on it can be had for a few dollars each, my "best" tubes that I have are a pair of USAF Tung-Sol 6AH6WA from 1961. The tubes have a great bass and nice treble that doesn't drive nails in your head like some of the 6AV6's do, especially the NEC 6AV6 here, the treble from it is so sharp it will cut hair... Nasty little tube, for me anyway, there are other styles of 6AV6's out there that are not as bad as that NEC one and do actually sound quite good, but you have to seek them out on eBay.

 

[Sonic Defender]

Just noticing the little Canadian connection at tis point in the thread. Thanks for the info Chris J, but I still wonder about this aspect of things. Given that the headphone resistance shouldn't be a huge factor in the obtained SPL level, if all those 880 versions are the same sensitivity (which I am not sure if they are), would you not expect them to require fairly similar voltages to achieve the same volume? If not I would have to assume that the resistance is the major factor at play here.

 

[Makiah S]

Oh yea watching some NET FLIX and WHOA... that DT 880 bass YEA BABY, seriously though guys BALANCE YOUR DT 880 it's gets a nice Visceral bass boost! We are not talking more quanity but DEEPER TIGHTER more controlled [and some what forward bass] either way, Net Flix [watching Season 1 of the Arrow] just switched to a Club Scene with some kickin bass! I was a happy camper at that moment <3 Bass was perfecto!