Add an IEC socket..any negative effects?

I'd be careful about adding a three-prong connection where the manufacturer used a two-prong. As a matter of fact, when the power cords of my Meitner MTR-101 monoblocks were damaged in transit (still don't know how), the manufacturer recommended using two-prong for a quieter background -- and it worked. It may be worth speaking to the manufacturer of your preamp or at least a knowledgeable technician who has worked on your model. Hope this helps.

Tatelman is on the right track, but I'm getting ready to do the same thing, and here's some good advice I got: whether you do the IEC or direct-wire, use a SHIELDED 3-prong power cord, but don't attach the ground-wire (green wire) to anything within the device OR to the IEC plug. These shielded cables usually have the shield connected on the 3rd (grounding) prong of the plug, and will do the trick for shielding the power lines, which definitely improves the audio. Good luck!

I forgot to mention this was advice for when your device originally only had 2 prongs for power. Of course, for 2 or 3 prong devices, you can experiment with attaching or not attaching the ground wire with the device, and see what differences there are. By the way, could I get some direction as to how to install an IEC port onto a chassis? I understand wiring, but the hardware end of things...I could use some help. Thanks! (email jtlusty@crosslink.net)

John, in your first post, did you mean the green wire that comes with the IEC socket? I could understand not "grounding" a component that wasn't previously grounded. However, if you meant the green wire in the power cord itself, I'm a little confused. Since I'll be using an IEC, I will not be using a hard wired wire. Please clear up what you mean in both of your posts. It sounds like good advise, I just dont understand when you are talking about the wire within the component, or the wires as in the power cable

JohnT: I believe a chassis punch for IEC's, and IEC's too, are available from Parts Express. Others here may know of alternative sources? G13: I'm thinking he meant to NOT connect the ground (usually green wire inside the component) to the IEC's ground prong. May or may not be a good idea sound-wise; definitely not recommended from a safety point-of-view. You could even experiment by installing a toggle switch on rear chassis-panel, to make or lift that ground connection. But then again, that too could affect sonics vs. a probably-better hardwire ground connection.