Hi,
I am the proud new owner of an SP2. It sounds great in my system but has a bad habit of blowing fuses in my amps. So, the problem occurs when I am watching cable TV, and I change channels. Even at very low volumes, a loud pop can be heard when you change channels, especially when you are changing between a Dolby 5.1 channel, and a *regular* binaural channel. I've listened to hours of music using other sources; the DVD loves the SP2. It is only when I change channels on the cable box that I get the fuse changing blues. I've tried using the optical connection and the coax connection. That isn't it. What seems to happen is simply, the digital signal drops out when the channel is changed, when the signal is reacquired, a loud pop is heard, and I have to change fuses in my Ampzilla Monoblocks again.
The SP2 is connected via RCA connections to 7.1 speakers. All the surround amps, and the center channel are NuForce Reference 9s. The subs are SVS PB12+. The main speakers are VMPS RM30s, powered by Ampzilla 2000s, and connected via Krell KAV 280p. In the Home Theater mode, the KAV is set up for unity gain. It has worked flawlessly for a couple years now, using a Sherwood P-965 as a source.
Also, it seems like the pop is independant of the volume setting. Mute does prevent the noise.