1. Both of these cards are unbalance inputs and outputs, are these vulnerable to noise or hiss of my recording since my power supply is not grounded? Is 1212M (balance input) better in this issue?
Personally, I can tell you the difference is like nite and day. Although I'm not using balanced cables ATM because of my synths, I can confirm the inputs as just plain surreal even when using unbalanced cables. Admittedly, I come from a 'blaster background having started with the AWE32, then SBLive, before I got my Terratec DMX 6fire. The 6fire was a revelation in terms of silent inputs and no DC offset to skew the waveform, something I had to do continually with the earlier cards.
My 1820m is sitting right next to my CRT, a precarious position considering the proximity to the flyback. Amazingly, the Audiodock isn't picking up any noise... but my cables are! At least the one's that are bad. I have a mix of very good cables and cheap cables and the cheap ones are like antennas. The shielding in those cables are probably compromised. I'm running Wavelab's realtime monitoring and the good unbalanced cables almost follow Emu's noise floor specs while the 'bad cables' are easily 20-30 db noisier. (Time for our Mogamis, eh Baldo?)
2. Is the 1212M a big jump in SQ? I'm attracted for the ADAT pipeline of this card perhaps can use in the future using my friend's Yamaha 01v96.
See above. I don't want to sound like a shill or fanboy for Emu, but I'm a happy camper with my 1820m. If there was something to niggle at, it would probably be the latency because I would like to keep it at 2 ms. Right now, I usually track at 5 ms. and mix at 20 ms and more because I like to use a lot of fx.
The Emu, especially with the 'm' converters, give you imaging that's almost beyond belief when paired with the right monitors. Ever since I got my 1820m, I could now pinpoint pan better and there is a certain clarity in my mixes now. I could hear slurring in bass notes, something that was all but impossible with the 'blasters. No wonder Sound on Sound made these their reference soundcards.
About the ADAT, you can use the O1V's adat outputs, but remember that the ADAT I/O of the Emus don't seem to have S/MUX capability so you're limited to 8-channels 44.1/48 khz operation; no 96 or 192 khz multiplexing. also, remember that the 1820m has already been discontinued in favor of the 1616m so if you plan to upgrade to the 1820m Audiodock, sorry. The 1212m is still in production and Emu is coming up with a new 1212m card based on lead-free ROHs standards.
Going back to your previously mentioned 2496, however, I can say that it's quite good as well. A guitarist friend of mine tracks thru one and he sends me some of his mixes to listen to. It may not have mastering converters, but I can say his recordings sound good and have very good imaging.
hth,
