A Question for the audiophiles and sound engineers in the Forum:

What is the Thinkpad with the best/HiFi headphones sound ever made?

I mean the quality of the internal sound card on the headphone output,
not the quality of the built in speakers.

Well, my T42 sounds better than my old T20 or T23 did with headphones, and maybe slightly better than the T30 or even the Z61t.

But...in my experience it's the headphones themselves that made more of a difference. And I almost always use my most expensive headphones, a Koss pair, with that T42. So like a lot of audiophile stuff, I think it all comes down to perception and the quality of the headphones.

Note I'm no true audiophile - not enough money - nor a sound engineer.

I tend to agree that headphones will make the biggest difference. However, for use in loud environments, like on an airplane, I have found the X100e to have the most powerful signal of all the machines I've flown with. I used an Echo Indigo PC Card with all prior laptops because even at full volume, I couldn't hear music or movies with an X22, X23, X24, X40, X41, X60s. However, with the X100e, everything is audible at about 50% volume level.

For excellent qualtiy, an add-on adapter, like the Echo Indigo, is your best bet.

I do actually use a closed studio headphone by Koss.

But I'm more interested in the specs of the internal sound system
inside the Thinkpads, because I want to attach one to my stereo amplifyer
as a jukebox and later also to some active studio monitors.

I'm getting acceptable resutls directly connecting the headphone out with the
HDD-IN on my amplifyer. Slightly better it is with the Roland Cakewalk UA-1G
external audio interface.

Besides a comment as a Thinkpad nerd: The UA-1G is black with a rubber
finish an a tiny red LED indicator. Just perfect next to a classic TP.

I was just wondering if any of the Thinkpads had a hifi-quality sound
equipment inside?

I just use my Etymotic ER4Ps with my T410 without any external devices. The integrated solution seems to be superior over the T43 in the SNR department.

I used to be a Sound engineer & was erm rather anal about Sound in my younger days & into higher end stuff for recording etc. But if i am being honest for general use,listening to CDs, mp3s etc (using as a digital jukebox as i have done) all the t20, X20 series & above should be fine. In my experience onboard Intel AC 97 chips (& their successors) do a decent enough job for most folks (including me) on playback.
Earlier sound i tried in very old models 600e, 570 etc were in my opinion not good enough.

Now the thing you probably need to look at is the output quality of the signal, then you will be getting into how the motherboard design may effect this, the db level produced & what kind of effect this may have on its ability to drive amps or headphones.
In my experience anyway a clear strong loud source output is always best, although you could get a headphone amp to boost the original signal if needed. My t42 headphone output was certainly louder than my x31 or x40. Size of machines?
However my X60s happily seems louder than the x31/x40, all were clear enough.
Mike Blake, Undeclocker & Navck al make good observations of real world use,
An external card may certainly improve things, Interesting that Navck nentions SNR (Signal to Noise Ratio) I went through a stage of being pretty obsessed by this when recording but then found out it is not the be all & end all. Besides i think for most playback as long as its around CD quality cant remember the exact figures 96DB? You should be fine.
Im certainly no expect on the matter but unless you are into multi channel Audio, for Stereo Playback the standard on board chip for most will suffice. If you are not happy with it or needed a better standard or maybe wanted to do some recording as stated you can always look for a decent cardbus/usb solution.
I use to be fairly up with what decent cards were out there, Back in my day M-Audio use to offer decent semi pro/consumer options but im sure things have moved on.

Oh poshgeordie who is a very helpful member on here, ex sound engineer & all round electronics whizz could i am sure offer a far more informed opinion.