Headphone

I'm using the 650's and an older, upgraded Headroom Cosmic.

Depends on what your source material is! Using C.F. will add a bit of upper bass and mid-range, which is useful for some CD's that sound bright, especially if you listen to Rock.

However, the C.F. blending can have some undesirable effects. If you are listening to albums that use panning effects, you will definitely NOT get the total side to side pan. This is very noticeable when the producer uses phasing tricks to place a sound to the "outside" of the speaker. Using headphones, the resulting re-centering of the effect can be quite dramatic.

The most interesting difference was on one of my favorite albums, Dan Fogelberg's CAPTURED ANGEL. Apparently, there was an out of phase problem on the master tape, because the highs always sounded "washed out" on both vinyl and CD, when listening to conventional speakers. Same effect using headphones with the C.F. on. Turning it off, the high frequencies literally jumped out, resulting in a major improvement...I had never heard the guitars sound so airy and open.

I would highly recommend the Stefan Art Audio Equinox cable for your 650's. Well worth the price and wait!

I'm using a Singlepower PPX3 SLAM to drive my Sennheiser HD-650's and absolutely love the combination! The "hardness"/"softness" dial is used to control feedback in the amplification circuit and is nice for tweaking. I don't really buy the crossfeed circuit, as this is something our brain does naturally when presented with biaural information... just my $0.02 though. There's a great thread on this over at headfi.org that you may want to check out:

http://www6.head-fi.org/forums/showthread.php?t=196753

I've had a headroom max for several years with various phones & sources & I have never liked the crossfeed feature at all. It adds some unnatural, annoying ambiance. I do highly recommend the max (last generation, preferably with the later reference module) as a great, smooth amp.
(I also dislike the the high filter.)

I also use the 650s (with a Zu Mobius cable), but now prefer the AKG 701s (they are more liquid-sounding, but the 650s may be better with any abrasive or piercing recordings).

Good luck.

Firstly, I do not think there should be any issues regarding importing from Meier Audio or other international manufacturers. Check out how easy it is over at head-Fi. I live in South Africa where it is much more difficult (much higher shipping costs, higher customs charges etc.) but ordering from overseas nowadays is fairly hassle free.

More on topic, I have a PS Audio GCHA running my HD650s and I love it. It does not have crossfeed but I run all my music via the PC with foobar and use either its built-in crossfeed filter or one of the numerous crossfeed plugins available.

Cheers,
X

I have owned a Headroom amp and preferred not to use the crossfeed. If your looking for an amp you should check out www.singlepoweraudio.com You can read many reviews and opinions of there amps on head-fi.com.
They are VERY good. I have had two offerings from Singlepower and have found nothing close to them when it comes to headphone listening.
Also the Zu Mobius aftermarket HD650 cable will really add to the alredy nice HD650.
Singlepower offers crossfeed as an option to there amps if you want it.