Like some other good meaning folks on here, I want to step up and try and make everything crystal clear. Once you read my post, you won't need to even consider an inexpensive Pro-ject turntable, especially the Pro-Ject Debut Carbon. I received my Debut Carbon today, 9/4/2014, and as I expected the hum was terrible. To be extremely clear, this is motor induced hum, it's not ground loop, it mechanical AC motor noise making it back to the arm and cartridge, and you will CLEARLY hear this annoying hum the second the stylus hits the record, between songs, during quiet passages, and at the end of the record, it's terrible. The fixes referenced in this thread DO NOT WORK, at least not for me. Today I spoke directly to Sumiko in Berkeley California, and you can be sure, they know all about this problem, but don't want to make a big deal over it, and I believe that is because many people who purchase a $399.00 turntable don't really realize IT'S NOT SUPPOSE TO HUM! Before I get into the real meat of this situation, let me tell you who I have spoken to. My first contact was Bill Rudolph, the Analog Manager from Sumiko in Berkeley. Bill's fix, send it back to the company you bought it from, he really does not want to address the design flaw with the AC motors at all, the less said about this by him, the better. The second person I spoke to was just very nice, however, he can't say too much either, Paul Green, the Manager of Sumiko's service department. Paul instructed me to totally remove the two screws on either side of the motor, where the Sorbothane grommets are, which I did and it made the hum about 30% more, so, with or without the screws there, the hum is terrible at best and horrible at worst. They have redesigned this entire turntable using a brand new DC motor, and I said, send me that one, and I will send you my AC motor model, which they would not do. They simply wanted me to return the product to the vendor and be done with me, which was my only option.
Ok, here is where the rubber meets the road. Forget all the fixes you have read, and go to this link and you will be completely educated on how this hum can be fixed, why it is happening, everything you have wanted to know about why this damn thing hums. This is by far the most comprehensive article I have read on the Pro-Ject Humming problems, it's excellent.
Once you have read the article and know that Henley Designs Ltd, the UK distributor for Project in Oxfordshire DID design a fix, however it's not for the Pro-Ject Debut Carbon. You have to go to their website to find this out, so we are still in the dark, with no way to the light, other than enjoy the loud hum or hope they have fixed the hum with the new model, just now making it to the United States, the Pro-Ject Debut Carbon (DC) model.
Speaking directly to the people that know, the Manager of Service for Sumiko, Paul Greene and the Manager of Analog Products, Bill Rudolph, THERE IS NO FIX FOR THE STANDARD AC VERSION OF THE DEBUT CARBON $399.00 TURNTABLE, NONE, IT'S GOING TO HUM, PERIOD, AND THEY DO NOT WANT TO GET INVOLVED.
When you read the long, informative article, you will clearly see what is happening, but when you go as far as I did, you will see, there is NO kit made to reduce or eliminate hum on the AC version of the Pro-Ject Debut Carbon turntable, and that came directly from the Henley Designs Ltd website!
I know the Debut carbon is a cool looking little turntable, but unless you can live with hum, something I don't even have on a $40.00 turntable, I advise you very strongly to stay away from the Pro-ject carbon turntable, and hey, it's not the only model that has motor hum, there are several. I would not touch a Pro-ject turntable under $2,000.00 for anything, as they are just not engineered correctly, and I have seen and heard this first hand.