This is probably a stupid question... so please forgive my ignorance I suppose I have a rather unusual setup which originated from my desrire to keep my hi-fi and home cinema systems in some way separate. Let me explain... My main stereo amp is an old Leak valve amp. I have my turntable connected directly to the valve pre-amp input which in turn powers my Ruark Crusader front speakers. I have just connected my MJA Pro 50 directly (via the high-level connection on the sub) to the valve amp speaker outputs to add a bit of bass weight to the music. Sounds wonderful (untouched by transistors - except the sub!) and I don't want to touch this setup if possible! I also have a Yamaha DSP-E492 which acts as switch for all my other sources - DVD, CD, VCR etc etc. The main speaker line-level output from this goes into a pre-amp input of the valve amp. The rest of the speakers are powered by the Yamaha's internal amps. There is also a low-level (filtered) output from the Yamaha to the MJA via phono lead to provide the 5.1 sub output. (Still with me? ) So basically I need to have both the low-level and high-level inputs to the sub connected at the same time. But the question is, what happens at the sub end when both inputs are connected and both are receving a signal, for example when I play a DVD or CD? Am I risking damage to the sub with this setup and is there internal switching or will both high-level and low-level inputs go through the sub's amp resulting in a bit of a mix-up? Any help/suggestions gratefully received!