Hi, hope you can help me with this. My Yamaha receiver (RX-V595a) has been a work horse since I bought it. Compared to my previous Pioneer, this receiver almost never got hot and had enough power for everything. But, after I took it to service due to a "mysterious cause" that damaged the center channel output, I became a little paranoid. Call me weird but I am constantly touching it to see if it's warm and I don't seem to feel it as powerful as before. The authorized Yamaha center took good care of it, in fact they cleaned it so good I thought that they'd given me a new one, honest! But my paranoid self is so picky that I "think" it used to sound a little louder and use to run mildly warm (I didn't use to touch it though, It all started since it came back from the service center). So it all comes to this, does the impedance switch (don't remember in which position it was) has something to do with it? It is in the lower position (Reads like this in the manual: MAIN: If you use one pair of main speakers, the impedance of each speaker must be 8Ω or higher. If you use two pairs, it must be 16Ω or higher. CENTER The impedance of the speaker must be 8Ω or higher. REAR: The impedance of each speaker must be 8Ω or higher. ) now, will it make it louder if I change it? will it damage something? is it safe? My speakers are JBL HLS series, 8Ω all the way, but the rear ones are 6Ω. The upper position of the impedance switch read like this: (MAIN: If you use one pair of main speakers, the impedance of each speaker must be 4Ω or higher. If you use two pairs, it must be 8Ω or higher. CENTER The impedance of the speaker must be 6Ω or higher. REAR: The impedance of each speaker must be 6Ω or higher. ) The Question is: Where does the switch has to be set? according to my speaker set that is. Please help, I'm paranoid, you guys are cheaper than a shrink (bad joke huh?) Anyone. Thanks in advance.