Mic Hum Problem

Guys,
I'm new at this so please bear with me. I have EMU1616m audio interface and AudioTechnica AT 2035 microphone. When I first plugged in the microphone, I got horrible crackling sound and I replaced the microphone. The problem continued. So I ditched the built in phantom power supply from EMU and bought a Nady SMPS 1X phantom power supply for about $20 bucks. It solved the crackling problem, but now I have a hissing sound when I crank up the volume on my EMU preamp (emu). It only happens at high volume levels, but that's the volume required for me to record and something lower is very weak. How can I troubleshoot this problem easily. I tried two different XLR cables and they gave the same result. So cables may not be the issue. I suspect EMU preamps since I also had trouble with Phantom Power supply, but there's no way to find out unless I try another audio interface. Is there soemthing that I can do easily to troubleshoot like try out a hum stopper or something? I read all these reviews on Audiotechnica AT2035 and it's also great. Nobody seems to have any problems with the mic.

Cactus is correct and you have found the weak link in the chain for the EMU solutions. The converters and Patchmix are the bread and butter, and worth every penny, but the preamps and DSP FX are nothing special. They're certainly not horrible but they're hardly stellar. Like Cactus said, spend the money and get a good a pre to take advantage of the converters in the 1616M... you'll have a great signal chain then. I would recommend an ISA One or Summit Audio 2BA-221.