I'm not sure what the deal is with the buzz in this thing. I have seen one or two other mentions of it, besides the review here. Some reviews specifically mention that there is no buzz whatsoever, another mentioned that there was a buzz specifically in the USB. In my case, I was getting a buzz from the headphone jack and the built-in speaker. I did not try the line out. I was all set to pack it up and send it back, but decided to just try the USB anyway. I was surprised to discover that there was no buzz in the USB output. Since my whole purpose was to convert vinyl to digital, and not to add a component to my stereo system, then the USB connection gives me all the capability I need. Even as a stereo component, the buzz might not be all that bothersome. It is not very noticeable on average-to-loud music, only comes forward on the softer passages. Indeed, I wasn't even aware of it until I brought up a digital recording (made from the headphone output) to edit. I saw the buzz on screen before I heard it, but once I was aware of it, it was intolerable for archival purposes. I wondered if the buzz might be caused by bad grounding or other interference in the AC circuit, but the buzz is still there even when running on batteries and nothing else whatsoever connected (i.e.--listening to the built-in speaker.)
Anyway, for what it does do, I am happy enough with this. I find the sound quality (from the USB!) to be more than adequate. I like the lightness and portability. It is very easy to set up and use temporarily, do a few records when time permits, and then close it up and get it out of your way when done, does not claim a dedicated chunk of real estate somewhere on your desk or on your shelf.
I would have done the "gain" knob for the USB a little differently. First of all, I would have placed it on the top surface (where the other controls--volume, tone, and speed) are, instead of recessed on the side where you can hardly see it (I have to use a flashlight!) and it's difficult to operate. Also, it would have been nice to have tick marks so that you can line up the notch on the knob with a specific gain setting. Also, it seems a little counterintuitive to turn the knob counterclockwise for increased gain.