Correct way of using a headphone amp with IEM's

If you are using the headphone-out on your DAP to the amp, than you should set the volume on DAP high (90% or more) and use amp to control the volume.

Some DAPs has line-out function like ipod classic, S-Flo2, X1061 and ipod Classic volume stop working when it connected with AMPs through line-out dock cable and DAPs HP volume has limit, it's better if it's on high volume when connected to AMPs and not on %100.

When using my iPod with an LOD, I can't control the volume on the player directly but in the case that I use its headphone out, I usually set the volume at 90% or so and use the amp to regulate the volume.

The question made in this thread is the same I have made to myself some years ago and I have considered it from the point of view of the electronic theory.

The full distortion that is measured from an audio device is made when distortion is measured at its full volume. Observe the distortion vs. output plots and you will see this.  So, if an audio source has full volume you will be amplifying audio at its most distorted output. And when it comes to amplifiers, they use tubes or ICs that add their own distortion. I think that is preferable to have moderate volume at the source, and then control the amplifier's volume. I think this gives less distortion. That is the reason many IC amps have negligible distortion measurements. On equipments that have LODs the volume is always at some average output, not full.

The point about LO is the signal is at line level, which means it has the best dynamic range, where the signal is at maximum before distortion increase, a.k.a. the best possible SNR the output can have. Most DAP today can easy output upward to 90% or so without distortion. For example, Sansa Fuze or Clip can output at 100% volume without any audible distortion, so if you are amping the headphone-out, you will be wise to set their volume at max to get the best dynamic range possible for amplification. Of course it all depends on the performance of the DAP itself.

Yes totally agree with you. For the sake of "clarity"  (in the equipment, that is) I use about 70% volume (if no LO is present) and then I play with the amp's volume.

Quote:

Originally Posted by ClieOS 

The point about LO is the signal is at line level, which means it has the best dynamic range, where the signal is at maximum before distortion increase, a.k.a. the best possible SNR the output can have. Most DAP today can easy output upward to 90% or so without distortion. For example, Sansa Fuze or Clip can output at 100% volume without any audible distortion, so if you are amping the headphone-out, you will be wise to set their volume at max to get the best dynamic range possible for amplification. Of course it all depends on the performance of the DAP itself.

Quote:

Originally Posted by iemmustiane 

what is a DAP?

Your mp3 player. I don't know the exact acronym, but it's your iPod, Fuze, whatever you use to play the music... my random guess would be that it stands for "Digital Audio Player"...?

I would go for digital audio processor.

Quote:

Originally Posted by Sinth 

I would go for digital audio processor.

2 for 3 isn't bad. ;)

It is player but it`s more "head-fi" with processor

Great Thanks!  My recievers company Denon said 75%.

Quote:

Originally Posted by vhbaske    I use about 70% volume (if no LO is present) and then I play with the amp's volume.

What effect does this have on clipping?

Guys DAP stands for Digital Audio Player (http://en.wikipedia.org/wiki/Digital_audio_player)  :)

I really think there isnt a number that can be used across the board. remember that the DAP has a fixed output level, so far as the amp itself, turning the volume up on the DAP does not increase the amplification level, it just attenuates it less. this attenuation is a digital process, so if your dap distorts at full volume, then it is generally because the output is too hot or flawed in some other way, output impedance is wrong, or cannot handle the load attached to it. the amp stage as with any amp, is at full gain the whole time, regardless of the volume setting