First, here comes my reference... http://gilmore2.chem.northwestern.edu/projects/showfile.php?file=cmoy2_prj.htm I'm completely a beginner. I want to build a amp for my SR80, I've been searched a lot and ordered the matiarials online. After I got those, I build it immediately. However, after I finished... My Cmoy doesn't work right. When I set it up, I can ONLY hear a little base.. nothing else. As I adjust the potentiometer to higher resistance, the sound goes crazy. It's all loud noise, no music. After I adjust futher, it went totally quiet. I've been very careful not to make mistakes when I was making it. I'm pretty sure there's no problem with soldering (altho I'm not an expert, I've been measured with a multimeter and there's no short cuts) The opamp was supported with normal voltage as well. The wire(22 gauge, way too thick, what gauge could be ideal for CMOY project?) and electrical tape that I used have no problem. So I am thinking maybe my design has problems ( I didn't make many changes compare with the original design). Also I might used my parts in the wrong way. I would be so appreciated and happy if anyone can trouble shoot it for me. I'm so stucked with it right now! So help me please! My design: (input and output are both grounded, not on the design tho) Other pics that might help PS: There's no R5 on my amp. The potentiometer I used in my project was Panasonic EVJ-C20 10 kΩ. Thanks a lot!!!