TYOH it is not just you. I have had my HD 500 for several years and did a firmware update in December 2014 and the electronic hissing is horrible and the distortion is the worst. With the factory settings I was able to achieve natural overdrive sound and tone, but with the update every single overdrive/distortion setting is the same. I am on here to make sure I can reset mine back to its factory settings to regain the ability to achieve the natural tones that it originally came with. Right now it is just another digital processor. I realize your post is a bit old, but it still applies, the factory settings are much better than any of the updates.