Portable amp for AKG K7xx

[Sherako]

So I obviously just ordered the AKG K7xx's. What amp is good for them. I have the O2, but I'm only going to be carrying it around if this thread doesn't help me. Okay, so what is a good amp for 62 Ohm headphones? Obviously with non-USB in, WAIT, can mobile devices output digital audio!? Prob not but whatever. I have power bank if that is a part of the setup. Under $100 USD. Sorry if this is hard to read, can't say without breaking COC/Rules whatever. I saw some Altoids amp, yeah. I like how FiiO's stuff looks, and WTF is FiiO's website or do not have?

[EmoRarity]

They really dont need an amp in the first place, but w/e

[CHEEZE-IT]

Mobile phones can use usb dacs. iPhones have the camera connection kit and android phones can use an otg adapter. With android you want android 5.0 or a rom that supports usb audio. android lollipop added support for digital usb audio. As for amp/dac portable solutions i dont have any suggestions but i want to hear what other people think. But i have heard good things about the C5 amp/dac from JDS audio. Theres also alot of fiio solutions.

[SSL]

Why don't you wait till you have the damn things before you run out and buy more shit, hmm?

[spwath]

Why don't you wait till you have the damn things before you run out and buy more shit, hmm?

I would like to know amps for them too, i dont have mien but they are about to be here in 2 days, so i can get stuff for them

[Sherako]

Why don't you wait till you have the damn things before you run out and buy more shit, hmm?

Very logical.

[Sherako]

Mobile phones can use usb dacs. iPhones have the camera connection kit and android phones can use an otg adapter. With android you want android 5.0 or a rom that supports usb audio. android lollipop added support for digital usb audio. As for amp/dac portable solutions i dont have any suggestions but i want to hear what other people think. But i have heard good things about the C5 amp/dac from JDS audio. Theres also alot of fiio solutions.

I like Cheez-Its now... 

[creatip123]

There's an explanation/analogy I read somewhere on the net. Let's say you're buying a new garden sprinkler for your garden. Sprinkler = headphone. Now there's a chance that your public plumbing or existing water pump already got enough pressure to use the sprinkler, and there's a chance that it's not, meaning you'd need an additional water pump dedicated  to push the sprinkler. Existing public plumbing/water pump = device's internal amp, additional water pump = additional amp or dac/amp combo.

 

What's the best way to go?

 

- Get the sprinkler and the water pump, gambling that you'd need a dedicated water pump, and if it turns out that you don't need it, you'd have wasted money on a redundant water pump

or

- Get the sprinkler and try to run it with the public plumbing/existing water pump first to see if it will operate nicely or not. If it's not, it's not really to late to then go shop for a water pump.

 

A Fiio E6 will work just fine for a portable amp.

 

To use DAC with iDevices, to extract digital audio data: http://linustechtips.com/main/topic/151857-ipadidevice-mobile-audio-solutions-image-heavy/

[NannerBeans]

Why don't you wait till you have the damn things before you run out and buy more shit, hmm?

I don't do that...

[SSL]

I don't do that...

 

Maybe you should...

[Scratchy1215]

I just got my AKG 701s and a FiiO E11 and it sounds great. My headphones work without the amp but max volume from my pc and phone don't even make the headphones all that loud. It sounds fine but with the amp it sounds much better.

[ShearMe]

They really dont need an amp in the first place, but w/e

They do for most people.

[ZycaManiac]

 

So I obviously just ordered the AKG K7xx's. What amp is good for them. I have the O2, but I'm only going to be carrying it around if this thread doesn't help me. Okay, so what is a good amp for 62 Ohm headphones? Obviously with non-USB in, WAIT, can mobile devices output digital audio!? Prob not but whatever. I have power bank if that is a part of the setup. Under $100 USD. Sorry if this is hard to read, can't say without breaking COC/Rules whatever. I saw some Altoids amp, yeah. I like how FiiO's stuff looks, and WTF is FiiO's website or do not have?

I also got that Massdrop K7xx here, and I tried it on various phones, tablets and even my notebook, as well as an USB DAC/AMP combo unit.

(Disclosure: I'm the designer of that USB DAC/Amp combo unit, as well is the seller for it.  Take it with a grain of salt, or a bag of salt. )
 

 

Now I'd like to clarify a few basic concepts, lower impedance means lower impedance, it does not have anything to do with headphone is easy to drive or not.  Low impedance headphones CAN be extremely hard to drive as well, and please remember, stereo speakers usually have 8 ohm impedance, but no one ever dare to drive them with your cellphone's headphone out.

Lower impedance headphones can demand a lot of current, and when it exceed the limit of your phone's capability, it can sound REALLY bad. (Try Sony's XBA-4, it have impedance of 8ohms, and sounds positively bad without a proper headphone amp)

 

Large headphones like K7xx simply demands more power to drive more mass, to fill a much larger area with sound requires more energy, and most phone don't have that kind of power.  Mostly because it costs power, and it costs precious space inside the phone to implement a good headphone amp.

 

• With my Thinkpad W520, that was a big mistake, the low freq sound are flopping around like jello, it is so disgusting that I stopped right away.
  This basically mean that the output of W520 does not have very good dampening factor, it can punch out the power needed to move the voice coil, but when it gets moving, the coil creates its own power that interferes with amp's attempt to control it.  If you hear a drum slams but does not quite stop as cleanly as in real world, that basically means the amp is having trouble controlling the diaphragm's motion once it got moving.
   
• With my Samsung TabPro 10.1, it just basically felt like the bottom end is not quite there, it doesn't sound like jello as does my notebook, but it also doesn't produce much bass to speak of.  I suspect it is possibly due to the use of output capacitor, which will adversely affect the bottom end if it is not large enough.  And come'on, the tablet is so thin, I don't think electronic engineer are given enough room to stuff proper sized capacitors.
   
• With my Sony Xperia Z2, it sounds much better compared to my notebook, and moderately better than samsung tablet, but it still lack the power to present stuff like "Phantom of Opera" properly.  With higher energy music (that's how I refer to music with instruments playing in most of the frequencies, fairly loud too), it just isn't able to compose sound properly to give you that illusion of being there.
   
• With USB DAC/AMP (PDM-10s), it is able to reproduce the music quite well, and produce MUCH higher output for music that needs it.  For some reason I was not able to run it from Xperia Z2, but I was able to run it on Samsung's TabPro 10.1 quite well.  (I'm guessing the power cap on the PDM-10s is a little too large, causing Z2's current limit function to trip.)

 

My setup now: 

[creatip123]

• With my Thinkpad W520, that was a big mistake, the low freq sound are flopping around like jello, it is so disgusting that I stopped right away.

  This basically mean that the output of W520 does not have very good dampening factor, it can punch out the power needed to move the voice coil, but when it gets moving, the coil creates its own power that interferes with amp's attempt to control it.  If you hear a drum slams but does not quite stop as cleanly as in real world, that basically means the amp is having trouble controlling the diaphragm's motion once it got moving

 

 

I'm actually thinking of adding a resistor in my amp's headphone out, to deliberately add output impedance. My headphone, the HE400, is a fast headphone, a bit too energetic for my taste. In theory, more output impedance could make it slower, but in reality I don't know yet. I'll try it as soon as I got my hands on some resistors.

 

 

With USB DAC/AMP (PDM-10s), it is able to reproduce the music quite well, and produce MUCH higher output for music that needs it.  For some reason I was not able to run it from Xperia Z2, but I was able to run it on Samsung's TabPro 10.1 quite well.  (I'm guessing the power cap on the PDM-10s is a little too large, causing Z2's current limit function to trip.)

 

I think it's the USB enumerator on the DAC. When it's connected, the device (in this case, the Z2) reads the USB enumerator to get basic info, such as how many ampere does it need to draw. If the DAC's enumerator reports a number beyond the Z2's allowed limit, it won't allow the DAC to be used. Same thing happens in iDevices. A workaround is to use a powered USB hub in between. 

[ZycaManiac]

I'm actually thinking of adding a resistor in my amp's headphone out, to deliberately add output impedance. My headphone, the HE400, is a fast headphone, a bit too energetic for my taste. In theory, more output impedance could make it slower, but in reality I don't know yet. I'll try it as soon as I got my hands on some resistors.

 

It will change the frequency response, you can check out the difference between ER4P and ER4S as an example, they are essentially the same earphone, but S got a resistor in the audio signal path.  Could be interesting to see the result.

But by energetic, do you mean sounding harsh or sharp? Early on, I had some pretty bad experience with Music II headphone from Grado, it was not comfortable AND too sharp sounding.  However, when I was testing my prototype DynaLo headphone amp with it, damn, all the sharpness is gone, it is smooth and sweet.  It is just another example of low impedance headphone that is not as easy to drive well as it is to just drive loud.

What kind of headphone amp are you using with HE400?

 

I think it's the USB enumerator on the DAC. When it's connected, the device (in this case, the Z2) reads the USB enumerator to get basic info, such as how many ampere does it need to draw. If the DAC's enumerator reports a number beyond the Z2's allowed limit, it won't allow the DAC to be used. Same thing happens in iDevices. A workaround is to use a powered USB hub in between. 

 

Actually I found out the reason, I just tried again with a "split power OTG adapter" that allow me to power up the DAC ahead of time, and then plug it in.  The phone accepted the DAC just fine and is playing now... Damn, I can't stop grinning.  For some reason the same adapter didn't work a couple of days ago, maybe the power on sequence wasn't quite right or something.  I'm just glad both my android device is happily working with PDM-10s.

[creatip123]

It will change the frequency response, you can check out the difference between ER4P and ER4S as an example, they are essentially the same earphone, but S got a resistor in the audio signal path.  Could be interesting to see the result.

But by energetic, do you mean sounding harsh or sharp? Early on, I had some pretty bad experience with Music II headphone from Grado, it was not comfortable AND too sharp sounding.  However, when I was testing my prototype DynaLo headphone amp with it, damn, all the sharpness is gone, it is smooth and sweet.  It is just another example of low impedance headphone that is not as easy to drive well as it is to just drive loud.

What kind of headphone amp are you using with HE400?

 

 

It's fast-on-fast-off. Everything sounds so tight. Not saying it's bad. Maybe good for fast songs like Greenday or something like that, but that's not my kind of song.

 

I'm thinking of adding a resistor in the ground cable. I'm not sure if by doing so I'm adding the output impedance of the amp, or the impedance of the headphone. Actually tried this with a scrap 20 ohms resistor. It does sound a bit different but not much, not really worth the effort. 

 

The amp is Aune T1

[spwath]

I also got that Massdrop K7xx here, and I tried it on various phones, tablets and even my notebook, as well as an USB DAC/AMP combo unit.

(Disclosure: I'm the designer of that USB DAC/Amp combo unit, as well is the seller for it. Take it with a grain of salt, or a bag of salt. )

Now I'd like to clarify a few basic concepts, lower impedance means lower impedance, it does not have anything to do with headphone is easy to drive or not. Low impedance headphones CAN be extremely hard to drive as well, and please remember, stereo speakers usually have 8 ohm impedance, but no one ever dare to drive them with your cellphone's headphone out.

Lower impedance headphones can demand a lot of current, and when it exceed the limit of your phone's capability, it can sound REALLY bad. (Try Sony's XBA-4, it have impedance of 8ohms, and sounds positively bad without a proper headphone amp)

Large headphones like K7xx simply demands more power to drive more mass, to fill a much larger area with sound requires more energy, and most phone don't have that kind of power. Mostly because it costs power, and it costs precious space inside the phone to implement a good headphone amp.

• With my Thinkpad W520, that was a big mistake, the low freq sound are flopping around like jello, it is so disgusting that I stopped right away.

  This basically mean that the output of W520 does not have very good dampening factor, it can punch out the power needed to move the voice coil, but when it gets moving, the coil creates its own power that interferes with amp's attempt to control it. If you hear a drum slams but does not quite stop as cleanly as in real world, that basically means the amp is having trouble controlling the diaphragm's motion once it got moving.

• With my Samsung TabPro 10.1, it just basically felt like the bottom end is not quite there, it doesn't sound like jello as does my notebook, but it also doesn't produce much bass to speak of. I suspect it is possibly due to the use of output capacitor, which will adversely affect the bottom end if it is not large enough. And come'on, the tablet is so thin, I don't think electronic engineer are given enough room to stuff proper sized capacitors.
• With my Sony Xperia Z2, it sounds much better compared to my notebook, and moderately better than samsung tablet, but it still lack the power to present stuff like "Phantom of Opera" properly. With higher energy music (that's how I refer to music with instruments playing in most of the frequencies, fairly loud too), it just isn't able to compose sound properly to give you that illusion of being there.
• With USB DAC/AMP (PDM-10s), it is able to reproduce the music quite well, and produce MUCH higher output for music that needs it. For some reason I was not able to run it from Xperia Z2, but I was able to run it on Samsung's TabPro 10.1 quite well. (I'm guessing the power cap on the PDM-10s is a little too large, causing Z2's current limit function to trip.)

My setup now:

Hmm I guess I should get an amp for my k7xx.

My eb01(not -e) seems to have a built in amp, but I don't think it is powerful enough. I haven't tried them with an amp.

Any good 50-100$ amps to pair with my k7xx and eb01?

[ShearMe]

Hmm I guess I should get an amp for my k7xx.

My eb01(not -e) seems to have a built in amp, but I don't think it is powerful enough. I haven't tried them with an amp.

Any good 50-100$ amps to pair with my k7xx and eb01?

FiiO E6 should get the job done. An E7k or E11 would do well also if you want something fancier.

[Lutkeveld]

@creatip123 You can use the word fast as a description, but FYI it's not possible to have a fast headphone/driver. Why would extra impedance change the sound?

[creatip123]

@creatip123 You can use the word fast as a description, but FYI it's not possible to have a fast headphone/driver. Why would extra impedance change the sound?

 

Hmmmm, the way I understand it, high output impedance (less than 1:8) cause dampening problem, which is the driver will stop moving slower. This is my definition of slower headphone, slow-start-slow stop. 

[ShearMe]

Hmmmm, the way I understand it, high output impedance (less than 1:8) cause dampening problem, which is the driver will stop moving slower. This is my definition of slower headphone, slow-start-slow stop.

No.... Low damping factor merely means uneven power output vs the impedance curve of the headphones. As the amp's output impedance gets closer to the headphone's, voltage output drops

[Lutkeveld]

If it moves slower, it will just produce a lower frequency. It has to follow the waveform, you can't stay behind or jump ahead ;p

[spwath]

FiiO E6 should get the job done. An E7k or E11 would do well also if you want something fancier.

And those are amps, not amp DACs?

Edit: e11k same price as e11. Better?

[ShearMe]

And those are amps, not amp DACs?

Edit: e11k same price as e11. Better?

E7k has a DAC for computer use. Didn't know the E11k was out, but they should be basically the same. Get the k if they've the same price.

[spwath]

E7k has a DAC for computer use. Didn't know the E11k was out, but they should be basically the same. Get the k if they've the same price.

Was going to, looks prettier.