[Brent Hutto]

I recently bought an iPod Mini which I really like. It sounds good with some PX200 headphones although at some point I'll try "better" ones (or at least more expensive ones).

Anyway, I've been reading on this forum about how portables like the iPod, running on three to six volts and with questionable-quality output stages, aren't really up to driving any but the most undemanding loads like my PX200s. So generally people add some sort of simple amplifier and attach it to the line-out from the portable, right?

Where do full-sized CD players fit in this scheme? Are their output sections typically akin to an el cheapo headphone amp or is it really not much different than a portable. And BTW I am aware that the headphone output on the iPod Mini is particularly weak, although mine is the new generation one.

To be specific, I have a semi-ancient Adcom GCD-575 which has always sounded good in my home stereo system. I've plugged the PX200s into its output jack and can't really tell much difference the iPod at least on female vocal music with acoustic guitar accompaniment. Maybe I ought to try it on something more demanding of bass power, although the PX200 doesn't do much down low.

 

[neilvg]

Quote:

Originally Posted by Brent Hutto So generally people add some sort of simple amplifier and attach it to the line-out from the portable, right? Where do full-sized CD players fit in this scheme? Are their output sections typically akin to an el cheapo headphone amp or is it really not much different than a portable. And BTW I am aware that the headphone output on the iPod Mini is particularly weak, although mine is the new generation one. To be specific, I have a semi-ancient Adcom GCD-575 which has always sounded good in my home stereo system. I've plugged the PX200s into its output jack and can't really tell much difference the iPod at least on female vocal music with acoustic guitar accompaniment. Maybe I ought to try it on something more demanding of bass power, although the PX200 doesn't do much down low.

I'll try to put in a few words here. As for the first question, it depends on what kind of headphones you have, your px200's, which are easy to drive, will not benefit from the amplifier very much since the ipod may very well be getting almost all the mileage out of it.

Full sized CD players vary greatly. Generally speaking the line output is sent to a preamp of some sort (headphone or otherwise). A low impedence speaker or headphone is harder to drive because it stresses a receiver or amp by asking it to put out more current, and that can be trouble especially if your amplifier is incapable of putting out the amount of current the low impedance speaker demands. This is basically where the tires hit the road, so to speak. Difference amps in combination with different headphones of different impedence factors will mate in different ways and produce a wide range of output. This is a simplification but good enough.

I do not know anything about you Adcom GCD-575 so cannot comment. But my guess is that an amp will provide minimal if any benefits to you with those headphones. And also realize that between amps, there can sometime be exceedingly subtle differences and it becomes a matter of taste as to which subtle variety is preferred.

Neil

 

[pramod]

present cd players like marantz cd5400 or the sony players(cd/sacd) have a good headphone out put
marantz is 18mw@32ohms
sony if using the same headphone circuitry from their older models then it is 28mw@32 ohms
now both of these is just good power if ur using headphones having an impedance of 32ohms or less and a good sensitivity then there shud b absolutely no problem driving these headphones.

 

[Brent Hutto]

After posting my question last night I did a little listening test with the song "Gallows Pole" from a Page & Plant live CD. Now I'm pretty sure the iPod Mini is lacking in ability to drive those PX200s compared to my CD player. Once you get about 2:30 into that track and all the drums and instruments are going at once there's stuff you just can't hear playing through the iPod's headphone jack.

The CD player doesn't supply any more bass (I don't get a good enough seal on the headphones to produce hard and heavy bass) but all of the different string instruments come through even when the drums are pounding. There's one point where I think Jimmy Page must be strumming or frailing on the banjo (at about 2:42-ish) and all I can hear with the iPod is a slight rattle in the right channel whereas playing it through the CD player it's clearly a banjo and not a guitar. Cool.

Fortunately for me, I don't listen to that kind of music on the iPod much. Mostly I stick to acoustic stuff that's much more midrange oriented which the iPod/PX200 does quite well. But I assume a halfway decent headphone amp would really bring out details on stuff like Page & Plant.

 

[go_vtec]

iPod does have fairly descent headphone out circuit for a portable device, however a home CD player powered by amp can provide significantly better details, definitions and more dynamic sounds especially in bass area.

As you pointed out, your headphone is fairly efficient so it won't see much improvement using amp. Of course, you can always purchase a better pair of phones (say Audio Technica ATH-A500 or A900) to really hear how good iPod can sound. When I've tried iPod and A900 combo without an amp, I was suprised how good they sounded for portable device standard.