DT 770 pro 80Ω, AKG K550, or Ultrasone HFI-780. The AKG K550 is overall the best of the three, but is just outside your price range, and gives a little in bass power for clarity.

1.) AKG K550 2.) Grado Sr225i 3.) Senn HD600

Since you want the base not the headphones, I would remove the receiver from the sony headphones and wire the output from the receiver to a female headphone jack. Then you could plug the DT 990's into to the receiver.   To attach a headphone jack to the base you would need to find a place to...

This are probably  the most modded headphones on here. Here is a huge thread on modding them. http://www.head-fi.org/t/508459/sr60-mod   Steam works really well to open the headphones. I would stay away from the senn hd600 cable its both really long and thin.

I use Custom Grado 225i's and a turtle beach virtual surround sound unit.  They give you an amazing soundstage.

Blue is ground Red is right White is left

There should be holes under the thin felt and poking holes in it can increase bass. There is no point to remove the entire thing and removing the entire thing likely would hurt the sound quality. This thread covers doing this mod to grado headphones.

The 4g has more room then the 5g. You would need to do the compact flash card mod to the 5g to fit the caps inside. I don't believe that the iPhone 3g or the iPad have high end DAC that this mod is taping in to.   Quote:

thanks for this thread Bilavideo.   Here is what I have done to my SR-225i's so far...   Mods: Removed most of the plastic (still has the plastic grill over the driver) Removed the white mesh Vented the back of the drivers (huge increase in the base) Dynamat on the back of...

That happened when I built my Mini^3 the opamp was fried

You could try using wine to install the windows program on your mac. If that doesn't work VMware is better than parallels. Max works great for ripping. Songbird is great for flac playback on mac.

I built the same amp from that tutorial earlier this week with all the parts from Mouser and it sounds really good for $20 in parts