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How do I know if an amp has enough output power for 600ohm ?

FloraSerie

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Hello !

I have a Beyerdynamic DT880 600ohm, and I'd like to buy an amp in the 150 Euros range.
I'm new to this hobby and I'm not yet 100% confident with my knowledge of the technical terms. I've been looking into the Topping brand and unfortunately, they don't write the output power of their amps for 600ohm. Only up to 300ohm.

For example, the output power of Topping L30 is as follow : 280mW x 2 @300ohm.
I've been using this website (http://www.digizoid.com/power.php) to see what would be required for a 600ohm, 96 dB SPL/V sensitivity headphones, and it says that i'd need 41.83 mW to have enough power for 110 dB, at peak level. I'm not sure that i'm able to find the voltage / current given by the amp as well.

So how would I know if the amp would correctly drive my headphones ? How can I calculate that ? I also EQ the headphones to Harman so I guess that it might need a little more power since it lowers the volume.

If you have any advises regarding the amp I should get, be it from the Topping line or another, I'd be glad to read them as well !

Thanks for your time and your help !
 

NTK

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Welcome to ASR!

Power = V^2 / R_load​

When the amplifier is voltage limited (and not current limited, which happens at low load impedances), maximum output power is inversely proportional to load impedance. The L30 is rated at 280 mW @ 300 ohms, and therefore will provide 140 mW @ 600 ohms (and will give you 5 dB more SPL than with 42 mW).
 

NTK

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After a little bit of investigation ....

Amir's measured max power output was 117 mW at 300 ohm.
https://www.audiosciencereview.com/...topping-l30-headphone-amplifier-review.15226/

And from Beyerdynamic's spec, the max power for DT880 is 100 mW.

DT880.JPG
 

3125b

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The L30 is rated at 280 mW @ 300 ohms, and therefore will provide 140 mW @ 600 ohms (and will give you 5 dB more SPL than with 42 mW).
... with 3Vrms input. As Amir measured it, 59mW is all you get.

You can more or less buy the Magni Heresy in Europe, you'd have to import the JDS Atom.
If you have an old integrated amplifier or something like that lying around you could also use that, the high output impedance wouldn't be much of an issue, if it's a particularly bad one the limited SINAD might be audible.
 

3125b

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Thats still importing it into the EU. Also, thats the DAC.
 
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FloraSerie

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Thank you very much for your help guys ! I'll try to apply this formula in the future.
I'll probably buy the JDS atom amp then. Seems like it's the one to get.
 

3125b

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Right, start of next year. However it costs at least 158€ delivered from that vendor, so importing it from the US would actually be cheaper.
 

NTK

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... with 3Vrms input. As Amir measured it, 59mW is all you get.
L30 has a +9 dB gain mode. If it is indeed correct, a 2 V rms input with give 5.64 V rms output, which corresponds to 106 mW @ 300 ohm (close enough to full power). Thus, the standard single-end/unbalanced line level of 2 V rms should drive the L30 to full output.
 

3125b

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Full output would be 9.17Vrms.
With its 9.5dB gain the output at 2.1Vrms input (real output of E30) would be 6.27Vrms, wich is 131mW at 300 and 66mW at 600Ohms. Amir measured a little bit less but whatever. 2Vrms input gives you nowhere near full output level.
With 1.1Vrms input from say an OnBoard audio chip from a mainboard, the maximum output of the L30 would be limited to 3.28Vrms or just 18mW at 600Ohms. Wich is not that much.
With the Atom 1.1Vrms input would be 4.95Vrms output level or 41mW @600Ohms.
... and now I forgot what I was trying to say.
Point is: For normal listening levels, this is all more or less irrelevant. But the 600Ohm DT 880 definitely requires a fair amount of power to drive compared to other headphones.
 
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Jimbob54

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Full output would be 9.17Vrms.
With its 9.5dB gain the output at 2.1Vrms input (real output of E30) would be 6.27Vrms, wich is 131mW at 300 and 66mW at 600Ohms. Amir measured a little bit less but whatever. 2Vrms input gives you nowhere near full output level.
With 1.1Vrms input from say an OnBoard audio chip from a mainboard, the maximum output of the L30 would be limited to 3.28Vrms or just 18mW at 600Ohms. Wich is not that much.
With the Atom 1.1Vrms input would be 4.95Vrms output level or 41mW @600Ohms.
... and now I forgot what I was going trying to say.
Point is: For normal listening levels, this is all more or less irrelevant. But the 600Ohm DT 880 definitely requires a fair amount of power to drive compared to other headphones.
Yes. And the L30 and atom both more than adequately deal with 600 ohm beyers. At unity gain.
 
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FloraSerie

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Just to be sure, before I really study your posts and try to understand them 100% (I have to sleep !), you're saying that both the Atom and the L30 are ok as long as I activate their high gain mode ? But the Atom should have an edge in its output, is that right ? As far as I know it seemed like the L30 was a bit better overall, so if both are capable of providing enough power for a normal listening experience, I guess that I should choose the Topping L30 ?

Thanks again, and sorry for the dumb question. I'll try to understand everything a bit better when I get some sleep !
 

solderdude

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The DT880 can handle 8V continuously but has no issues with 12V.
To reach 'impressive' levels which you can only sustain for a short moment you will need about 15V (0.4W)
When you just want very loud which you can sustain for the duration of a song 0.1W is sufficient.
As the DT880-600 is quite insensitive you will need an amp that has at least a high gain setting IF you want to play comfortable loud.

This means an amp with 12 to 15dB gain and minimal 200mW in 300 Ohm or when you always want distortion free 'power' available 0.8W in 300 Ohm. There aren't many SE amps that can do this (John is working on one)
8V (200mW in 300 Ohm) will do fine for most people.
Because of the high gain needed to play loud and a low price I would suggest Schiit Heresy, JDS labs Atom

But to address your 2nd and valid concern. Your usage of EQ means the gain of 12 to 15dB may be a bit too low (so not power output but gain)
15 to 20dB gain would make more sense.
Schiit Asgard (16.5dB gain and power in abundance) or Heresy for cheap 15dB gain.
JDS Atom on high gain = 12dB gain.
The L30 on high gain and using a 2V DAC + software EQ may not play loud enough. It will be enough for casual to almost loud listening levels.

My advice: buy something with at least 15dB gain and capable of at least 200mW in 300 Ohm (= 100mW in 600 Ohm)
 
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Jimbob54

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The DT880 can handle 8V continuously but has no issues with 12V.
To reach 'impressive' levels which you can only sustain for a short moment you will need about 15V (0.4W)
When you just want very loud which you can sustain for the duration of a song 0.1W is sufficient.
As the DT880-600 is quite insensitive you will need an amp that has at least a high gain setting IF you want to play comfortable loud.

This means an amp with 12 to 15dB gain and minimal 200mW in 300 Ohm or when you always want distortion free 'power' available 0.8W in 300 Ohm. There aren't many SE amps that can do this (John is working on one)
8V (200mW in 300 Ohm) will do fine for most people.
Because of the high gain needed to play loud and a low price I would suggest Schiit Heresy, JDS labs Atom

But to address your 2nd and valid concern. Your usage of EQ means the gain of 12 to 15dB may be a bit too low (so not power output but gain)
15 to 20dB gain would make more sense.
Schiit Asgard (16.5dB gain and power in abundance) or Heresy for cheap 15dB gain.
JDS Atom on high gain = 12dB gain.
The L30 on high gain and using a 2V DAC + software EQ may not play loud enough. It will be enough for casual to almost loud listening levels.

My advice: buy something with at least 15dB gain and capable of at least 200mW in 300 Ohm (= 100mW in 600 Ohm)
Totally missed the OP saying he used eq. Solderdude nails it again
 
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FloraSerie

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Thanks for the in depth answer, I really appreciate it !
Unfortunately, the Asgard is a bit outside of my budget. I'll re-read the review about The Heresy and the Atom, but the Heresy indeed seems like the best choice for my use case.

Thanks everyone for being so helpful !
 

Sharur

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The DT880 can handle 8V continuously but has no issues with 12V.
To reach 'impressive' levels which you can only sustain for a short moment you will need about 15V (0.4W)
When you just want very loud which you can sustain for the duration of a song 0.1W is sufficient.
As the DT880-600 is quite insensitive you will need an amp that has at least a high gain setting IF you want to play comfortable loud.

This means an amp with 12 to 15dB gain and minimal 200mW in 300 Ohm or when you always want distortion free 'power' available 0.8W in 300 Ohm. There aren't many SE amps that can do this (John is working on one)
8V (200mW in 300 Ohm) will do fine for most people.
Because of the high gain needed to play loud and a low price I would suggest Schiit Heresy, JDS labs Atom

But to address your 2nd and valid concern. Your usage of EQ means the gain of 12 to 15dB may be a bit too low (so not power output but gain)
15 to 20dB gain would make more sense.
Schiit Asgard (16.5dB gain and power in abundance) or Heresy for cheap 15dB gain.
JDS Atom on high gain = 12dB gain.
The L30 on high gain and using a 2V DAC + software EQ may not play loud enough. It will be enough for casual to almost loud listening levels.

My advice: buy something with at least 15dB gain and capable of at least 200mW in 300 Ohm (= 100mW in 600 Ohm)
Does an integrated amp count as a single ended amp in this case? My NAD C 316BEE V2's headphone out gets the DT880 600 ohm ridiculously loud before even reaching half volume.
 

solderdude

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The output voltage on the HP out with a 600 ohm load = 7.2V peak (88mW) so very loud.
Output R = 68 Ohm. Fine for high impedance headphones can be terrible for certain low impedance headphones.
 

twsecrest

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Thanks for the in depth answer, I really appreciate it !
Unfortunately, the Asgard is a bit outside of my budget. I'll re-read the review about The Heresy and the Atom, but the Heresy indeed seems like the best choice for my use case.
Thanks everyone for being so helpful !
Me, I would replace the DT880 600-Ohm with a Soundmagic HP200 headphone, it's like a combo of the DT880 and DT990.
Seller off your DT880 and use that cash to buy a DAC/amp (Schiit Fulla 3?).
 

Sharur

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The output voltage on the HP out with a 600 ohm load = 7.2V peak (88mW) so very loud.
Output R = 68 Ohm. Fine for high impedance headphones can be terrible for certain low impedance headphones.
Thanks for the response! I know the 68 ohm output impedance gives a load:source impedance ratio of over 10:1, but does the high output impedance adversely affect things like impulse response and square wave responses?
 
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