I bought the Sennheiser HD 280 Pro headphones today and have a slight issue when playing with them through my amp--there is a weak but noticeable hiss/buzz. No problems when I use with them with my iPod-Touch. In fact they're exceptionally good mp3-headphones for $100. Here's my rig, to give you some background: -Ibanez SR506 (6-string) -Ibanez BTB675 (5-string), both of these basses are "active, 3-band EQ". -Ibanez Soundwave (35-Watt, SS-combo amp). I've had that amp for 10 years, but only been playing "seriously" for the past 2-or-so (I'm 23). I'm not playing with a band yet and put most of my $$ toward my basses, which is why I haven't been able to move beyond a practice-amp to a more sophisticated/powerful rig (which is my next project, but I still have more research/saving up to do). Still a great practice amp & has never had problems in the past. This is the first time I've ever used its Headphone-input jack, so I'm a little new to this. Anyways... I tried them out thru the amp with both basses and the HD280's are absolutely terrific in all of these categories: sound quality/tonal-clarity/frequency-response/external noise-reduction. But, that "hiss" is still there and it's the same on both. This can't be coming from the bass, though. I put new 9V batteries in each of em and I also made sure that this wasn't happening from sitting with the bass too close to the amp, or having some other electronic source nearby that would interfere with it. So I've narrowed it down to 3 possibilities: A.) It's my input cable (bass guitar --> amp), which probably isn't a "top-notch" or high-quality cable and have had for several years. However, I haven't had any problems with it in the past and I don't really hear or notice an amp hiss/buzz when I'm just playing through the speaker. B.) It's my amplifier, the head (preamp/power-amp) component. But the only reason I would suspect this is that it's just a regular $250 practice-amp that I bought 10 years ago. Still, I've never had issues with it before and it's in as good of a working condition as it's always been. Also, I played around with the tone knobs on both the amp & on the bass, just to make sure it's not EQ-related or the result of too much volume/gain/treble/presence. Interestingly, the hiss I'm hearing through the headphones doesn't get louder, softer or vary in any way when I touch the tone controls. C.) It's the headphones, themselves. Obviously they're not "top-shelf" quality like the ones that a music producer would own. But based on how well they reproduce the sound of my basses @ various different EQ settings, I'm reluctant to think it's this option as well... Damn.. I'm sorry about the length of this post, but would really appreciate as much advice as I can get from you guys. What do you think's going on, here/is this normal to have? It's only a soft hiss nor is it significantly distracting. And I can live with it if I have to, but would definitely like to get rid of it if possible. Thanks in advance!