I remember coming up with similar issues when I first got my big pair of headphones (HD650's) albeit I think that I had a NEED for an amp whereas in you're case, an amp would be a luxury of sorts (then again so is anything outside of bread and water) for a pair of grados. While grados will do better with some amplification, I would hardly call them crippled or diminished by running them out of your computer. Just grab some good quality songs and output through your computer and you're good to go. On the other hand, a portable amp would be recommended with your ipod to bypass the ipod's internal amp. I used an RSA tomahawk as well as an Ibasso D2 Viper to pair with my ipod in the past and was happy with the results. Since the grado's are on the easier side to amplify, you won't really need to delve into the realm of the LISA III, diablo etc... and a lot of the much smaller/portable amps will do. I may even go so far as to say that a simply well built CMOY amp would do or a Fiio E5 let alone a Fiio E11. My suggestion is decide if you would like to upgrade your ipod set up or your computer. If the choice is with the ipod, go with a good Line out Dock and just grab a small amp (i.e. Fiio E11, the fiio e5 worked for me but have never tried the fiio e11). The whole set up should cost you at most $70 and less if you buy used and shop around. Then in a few months when your ink is dry, pick up another source.