Just one more question and i think i can figure it out:
Is the o2+ ODAC better by leaps and bounds over the idsd? I know it's not as portable but considering i'll probably keep it at home, is it worth the investment so i can use it on multiple headphones?
I don't have the ODAC, just the O2, as I'm very satisfied with my current DACs. Whenever I'm at home and deciding which one to use, I've always struggled in deciding.
The O2+my DACs (see sig below), if there's a word to describe them, sound "crisp" and "solid" on the treble and bass, respectively. The mids has that "silky-raw-transparent" sound into it. But take note that I mainly use my Audiolab 8200CD (as source player and DAC), which had multiple digital filters and the famous ESS Sabre 9018 DAC chips. I use mainly the Minimum Phase and Optimal Transient filters, which sounds very organic, natural and analogue-like. It also has a linear phase filter labelled as Optimal Spectrum, which is similar, I believe, to the ODAC's digital filter. Doesn't prefer it as it sounds "digitally" to me.
Otoh, the iFi nano/micro iDSD sounds very "silky-smooth" and "full/deep" to me on the treble and bass, respectively. It's also very detailed, like the O2, but it brings out a certain house sound that's different from the O2's sound. Mids and treble are silky-smooth, and the bass are very deep-reaching with mass and volume, hence the descriptive word "full".
IMHO, you can't go wrong with either. If I'm in your situation, I'll probably go with the iFi nano iDSD as I now like chilling and moving all around the house and not fixed to one place, so portability is a factor there (btw, ODAC isn't portable). As to purely SQ considerations, it's hard to decide which one is better. I just can't. When I use my O2, I always miss my iDSD. If I use the iDSD, I always miss my O2.
Sorry to contribute to more confusion...
If you've got the money for O2+ODAC, try the iFi nano iDSD for just a little additional chunk of your income. The sound you'll go into would just depend on your ears and liking.
Cheers.