which headphones???

For all around listening flexibility and comfort at a reasonable price the Sennheiser 600 is extremely hard to beat, I have tried most of the main contenders under $500. If you search internet you will find Senn 600 for @$250 new, they must be driven by good headphone amp however because of high 300 ohm impedance rating vs 32 ohm rating for Grado. (which is another topic)

I have a couple other headphone sets for variety, but if I had to have only one it would be Senn 600. There are aftermarket cables that replace stock ones and improve performance even more.

The mecca for headphone gear is Headroom:
http://headphone.com/layout.php

Megasam, I agree! I have both the Sen. 600 and the Grado SR-125. I am using a Headroom Cosmic (battery portable) amp, and the Sen. 600 is a far superior set of phones. However, it is much more difficult to drive and does not play as loudly. For cruising on the backroads of the Sonoran Desert with the windows down/sunroof open, the Grado-125's are the choice (wind noise). When in the hotel room, definitely the Sen. 600's!

You might try upgrading within the Grado line. My 225's have decent bass response.

Could someone please explain to me why, as previously quoted;

"must be driven by good headphone amp however because of high 300 ohm impedance rating vs 32 ohm rating for Grado."

8 ohm impedance is easier to drive in normal speakers that 4 ohm, so why does it appear the other way round with phones?

My amp, an Audiolab 8000LX has the following stats:

Headphone output:

Output Imp: 330 Ohms
Suitable for headphones 8 - 2K ohm Imp.

Will the Senn 600's be OK with this?
(I am currently using a tired old pair of BeyerDynamic DT 331's - 40 ohm)

Thx in advance,
Josh

Joshcloud ... an 8Ohm speaker impedance is easier to drive for most amplifiers because it draws less current than a 4Ohm impedance, and most cheaper amps are more limited in their ability to drive current than voltage, because high current equals large power supply equals expensive parts.

Now I think that headphones require very little current, but a 600Ohm headphone will require 10 times the voltage of a 60 Ohm headphone in order to drive the same current. In battery powered devices higher voltages are bad news for battery life, and so a small battery powered portable might have difficulty and/or very short battery life driving a pair of HD600s.

In summary the limiting aspect of the design of an integrated amp (current limited) and a portable CD player (voltage limited) are very different, leading to the apparent contradiction in driving capabilities. Hope this makes sense.

Your audiolab amp should have no problem at all with HD600s. I have an audiolab 8000C preamp and it drives higher impedance headphones with ease. My Marantz CD67SE headphone socket will also drive the higher impedance phones with ease.

So I think the HD600s will work with most decent mains powered equipment but might struggle with battery power.