Have you looked for it on archive.org?
Unfortunately, I didn't try the site you've listed to see. I will do some more digging to hopefully see it cached somewhere.
As a follow up to some of the impressions provided by Joe Doe, I can see where it is quite clear that the SennGrads do not really need amplification and if utilized, one could really not tell any difference when the headphones are connected to one -- unless the amplifier does color the sound a bit, or if the DAC used in conjunction with the amp would add some improvement in sound. Aside from those two components and potentially changing the sound signature, that would be the only reason where I'd indicate one could use an amp and a DAC. Also, to utilize such components might mean adding additional components (and money) into the chain when one really doesn't need to invest the additional $150 on the low end to $1,000+ or more on the high end.
A few mornings back, I went between the output of my Harman Kardon AVR-310 receiver with the headphone output and connected to my oDAC, as well as the iPod Classic model 7 music player that I have. The iPod was just running "neutral" and I didn't have any form of EQ or tone adjustment applied. With the iPod, I didn't have the volume up very high at all, yet the sound was being produced at a nice, comfortable listening level without any strain. There was also quite a bit more distance in the volume control before one would get the iPod player to the level of distortion. I did not push the iPod to that level at all, because doing so would not make any sense at all. The sound difference between the iPod and the H/K / oDAC configuration was slightly different. The iPod had a bit more weight to it, but that doesn't mean that the H/K / oDAC option was "light" in any way. It just was a good experience that spoke volumes about the capability of using the SennGrads with the efficiency in the high-90s decibel range.
Also, though, between switching between the sources, I would quite possibly give a slight nod to the H/K oDAC option (more on that a bit later) as I could sense a bit of a better width in the soundstage based on the music tracks that I tried. Granted, not a significant amount, but still one that could be determined and heard. The iPod Classic 7, though, certainly did not disappoint when one considers that it is a $120 - $150 (used market) player with a sizable hard drive for lots of music and a good battery life. Pair that with the SennGrads having the foldable headband (for very portable storage) and the very lightweight that is offered, it makes for a very portable as well as comfortable (from a weight aspect) pair of headphones.
Where I heard the best details, happened to be with the various jazz tracks that I'd use for listening. The instrument sound was very realistic and the distinction between the instruments could easily be heard. There are quite a few headphones out there that are a bit weak when it comes to instrument distinction. I know for me, I'd rather have the option for hearing great separation - from a stereo sense, as well as the separation of the instruments, too, which is what really engages me when it comes to the music. What I could really appreciate was the percussion used in the jazz tracks. The separation was quite vivid and often I'd hear a part of the track appear through one of the sides, but a few inches behind my ears, to further demonstrate the depth of the soundstage.
I really hate to come across as loving these too much. It seems like I'm trying a bit hard to promote these. In a sense I am, but that is just because I'm enjoying what I hear and I've had more than a few dozen headphones through my listening section to be able to equate to what my ears prefer and what they just think is OK, but not excellent. Finally, a note on the SennGrads. I've realized that I can be quite critical of the sound of a headphone because when I drop some coin on a pair of headphones, I really want to ensure they are something that I could really enjoy - and during a relatively long period of ownership (yeah, like that will happen), but that I really do mean.
Now, a note about upgrading. Very frequently, one will own a pair of headphones (let's just say hypothetically $150 headphones). After a period of time, the owner might get to really enjoy the headphones, but then they do take some time to read reviews on sound impressions for another pair of headphones (again, $300 headphones in this hypothetical example) and then the person gets a plan together to work out a process to achieve that next pair of headphones. Does this always mean that the person during the upgrade will achieve a 100% upgrade in sound because they've doubled their investment? Not really. I've been in that position many times and have felt that where I've anticipated an upgrade, it turned out to be a lateral move in the sound department, yet I just went through the exercise of spending money to realize what just happened.
I also have another paragraph on cheap amplification. As noted in earlier posts, I've been noting the differences between some of my headphone amps as well as some full-sized receivers and amps that I've been trying out due to the low cost when you find a gem on Craigslist. The latest addition happens to be the Harman Kardon AVR-310 receiver. A bit aged at this point when one considers that H/K has gone trough a few design phases and about 6 or 7 model revisions since the AVR-310 was released. However, the good thing about newer receivers as opposed to vintage receivers is that one hopes they'll have a bit of better life because they have a receiver with newer components (caps, etc.) that, in theory, should provide a longer life. Plus, these receivers are very abundant in the used market because people who are into home theater gear tend to switch out their gear based on revisions to processing formats, video switching capabilities, etc. This means that this "surplus" of receivers allows for them to be listed at relatively cheap prices (less than $100 usually). When new, these receivers would have sold on the $500 to $700 range. The AVR-310 is a real gem. I mean a real gem. As one who has owned many home theater receivers, but never used any of the previous ones with headphones, I can confirm that the H/K does have a beautiful sound to it and this can be often noted in the reviews of such receivers. In the situation with the H/K, it doesn't appear that they hurt the headphone output with respect to sound quality just so that they could advertise that the receiver had that option. I really is a joy to listen to with the headphone output section. It is not harsh on the upper end and the mid and lower ends offer a lot of clarity and quality. When I use my Beyerdynamic DT-880 (250 Ohm version) with the H/K, the upper frequencies just sound wonderful. They have detail, but they are not overwhelming, nor overbearing either. Nothing but beautiful sound on a shoestring budget.
Enjoy!
