Denon mixer hiss

I own a Denon Dn-X1500s mixer (built 2004). Anyone have experience with a small hiss coming out of the master? Or anyone else experiencing any hiss from other Denon mixers? Besides this (annoying) downfall, I still covet this mixer.

I'm still debating whether to get on the bandwagon and purchase an used Pioneer mixer. I love a lot of the features about them, except the headphone amp is quite low compared to that of the Denon (I'm mainly talking about the Master side of the PFL cue).

Any advice is appreciated. Thanks!

The headphone out seems plenty loud enough on my DJMs at around 11-12 o'clock