um2 with the xenos headphone amp?

[vii_haven 0]

i tried the xenos portable headphone amp and the crossroads portable headphone amp at jaben that day. seems like the xenos was a better match with my ipod3G and the um2. anyone has the xenos amp and the um2 and care to share some reviews on them? what other amps are there around that i can consider?

[scanfiend 0]

Here ya go....

 

http://www.sgheadphones.net/index.php?showtopic=5165

 

I would suggest you hook up the amp via your headphone jack rather than the line-out of you ipod....unless it has a "true line-out" rather than a "max or constant volume" type of line-out

 

I do not have an ipod, so YMMV. Try out the 2 connections and pick the one you like best

Edited September 11, 2006 by scanfiend

[theory_87 0]

Here ya go....

 

http://www.sgheadphones.net/index.php?showtopic=5165

 

I would suggest you hook up the amp via your headphone jack rather than the line-out of you ipod....unless it has a "true line-out" rather than a "max or constant volume" type of line-out

 

I do not have an ipod, so YMMV. Try out the 2 connections and pick the one you like best

ipod 3g had real bad bass roll off problem so line out is still his best bet. not sure about hdd ipod (everyone told me vol can be adjust) but for ipod nano, line out had max or constant volume.

[scanfiend 0]

but for ipod nano, line out had max or constant volume.

 

That's what I was talking about. It goes without saying that when the signal is pumped out at almost maximum volume, the audio would be terribly compressed, with very little room for dynamic transients before you run into the very real risk of signal clipping. I was playing extensively with line-outs on my DAP's over the weekend and came to this conclusion. Music sounded flat, muddy, congested, and has no dynamism and sparkle at all. In fact, I can only tweak the amp volume control just a little before it became unbearably loud for my UM2. Connecting the amp to the headphone out jack resulted in better sound for me, contrary to all the information I have read. That's because I can adjust the volume of the output (typically half max volume), and adjust the headphone volume via the amp.

 

That got me thinking....why is this so? A line-out is a line-out right? My almost 10yr old Sony PCDP sounded heavenly with the AKG 601 and the Govibe through the line-out. Then I came across this:

 

On the other hand, the final power amplifier stage of a typical audio device often introduces distortion. But "line out" is derived from some point before that final amplification takes place. So "line out" signals tend to be of higher quality than those from a speaker (or headphone) connector.

 

"Line in" expects the kind of signal "line out" provides. So you can typically connect the "line out" connector of one device with the "line in" of another. However, if you do this with a straight cable, and both devices are AC powered, you may run into ground - loop - hum.

 

A typical "Line in" inputs is actually a high impedance input with an impedance of around 10,000 ohms. When a "Line out" signal output, with its impedance of around 100 ohms, is connected to a high impedance "Line in" input like this one, the result is that most of the voltage (over 99%) appears across the input resistance, and almost none of the voltage is dropped across the output impedance. This is the desired effect. Since the impedances are far from matched, very little power is transferred, but the goal is not power transfer, it is voltage transfer. These are voltage signals (as opposed to current signals*) and it is the signal information that is desired, not power to drive a transducer (e.g. speaker) or (transmitting) antenna.

 

I stuck my headphones into the line-out jack and got horrible audio distortion and fade-outs (it's all in the interest of science ) Makes sense, since there is barely enough current to drive the headphone in the first place.

 

All this makes me wonder - the fact that the audio comes out at some kind of volume (listenable using the headphones, albeit very, very loud ) imply some kind of amplification taking place, not exactly the "line-out" that I expect Wonder why this is so? Maybe the highly integrated circuit design of modern DAP's preclude the genuine "line-out" output?

 

[vii_haven 0]

you can't adjust the volume for the lineout from the ipod 3G (done with an adaptor). who has the LDM+ and has compared it to the xenos XEP?