Just wondering, is the HD600 made in Germany like the rest of Sennheiser's high-end 'phones?

my 600's and 650's say Ireland.  I think I remember someone on HF saying that there are China models of these cans too, but that sounds fishy.

Pre-measurement Impressions.

CT sent these to me and I love them. They don't have super detail extraction, are a little bit murky in the bass (not too different from the HD650 bass really), but are well balanced. If there is a minor niggle, I think the region around 3-4k sounds slightly emphasized (compared to me reference systems.) We are not talking nasty peaks here, and the HD600's tonal accuracy still blows 95% of all other headphones out of the water, but it's something to note.

There's a reason why the HD600 is in the hall of fame / Pirate's booty.. I think people entering the hobby and wanting an accurate sounding open headphone that does well with a wide variety of genres and recordings should seriously consider this headphone. One of my favorite rigs early on (many years ago) was an HD600 <- 4-ch B22 <- tubed Chinese CD-player (a good sounding one)

A good HD650 doesn't sound too different from the HD600. The main difference to me is that the HD650 is more laid back in the upper mids.

Measurements later after I take a nap.

My impressions, pretty much; acquired and kept the HD-600 (and HD-580, since way back) on my way to HD-800 and Stax rig. Discarded the HD-650, which I have owned twice, used with several (not expensive) amps and find hopelessly colored, someone's idea of what a "audiophile" HP might sound like. Not close to the 600 in my opinion, and I for one would never have predicted the HD-800 from the company that produced the 650. But that's just me.

I have definitely heard differences between HD650 pairs.  Don't know if it is variability due to actual revisions or not.
 
Sounds like the HD600 variability can be attributed to pads at times...
 
Have heard HD650s that I really like (bit more upper mids/treble with a couple pairs).  Maybe what what I want is a pair of HD625 or HD630. 
 
Seems like you pick your poison at times:  a little too much 3-4Khz or a bit "not enough".