CeeTee,
Do you still use the GO with your HD 600? I'm considering purchasing an HD 600 to pair with my GO 720. I'm currently using the GO as my desktop DAC, and its 47 ohm port is connected to my studio monitors. Is the .47 ohm port adequate for driving the 600's? Which port do you use?
I do still dig GO 450 with HD600. Not the cleanest/most resolving because of HD600, but a fantastic all-around and reasonable in size/cost/performance combo. I think GO 450/HD600 is a great little combo and I use the 0.47 ohm out.
I recently got a GO 720 and find it a little more u-shaped than the GO 450. (I find the GO 1000 definitely a bit u-shaped, but nice with HD800 and classical/acoustic). I'll have to do a comparison when I am listening to HD600 again and try them with 450/720/1000. Will report back. I appreciate the sharing on this thread! (Still have to tape the pin on my USB Y-cable too.)
Right now I am messing around with GO 450 to Vali to HD800. Need to move everything around and try to get the Crack on my desk.
Another thing that I have been doing is using Darin Fong's Out Of Your Head Software (I have three presets) while watching Amazon Prime on my MacBook Air with Geek Outs. It's fun. Audio lags a little behind due to streaming and processing, but after a bit it is enjoyable, you kind of forget about the processing, and it adds to the fun of watching on a tiny laptop. I'll slowly test through my phones and the 3 presets I chose.
Having fun rotating phones and combos, haven't had enough time to really test everything against each other to see which ones I will keep long term. When I had GO 100 prototype, 450, 1000, the 100 and 450 were pretty close in tonality with the 450 definitely more powerful. The 1000 was U-shaped so I sold it but then I missed it so I bought it back.
When a blue 720 popped up, I was curious (and also really like the blue color) so I nabbed it. Don't know if I will keep them all, especially with ODAC in the house and Geek Wave portables coming in 2015. The 450 is my overall favorite but they are all good enough that having at least one around for versatility/performance is a good idea. Three is greedy, I know.