feesh 0 Report post Posted January 3, 2009 Hi guys, i purchased a cmoy kit from jaben a long time ago. i only decided to build it this evening as i intend to give it as a gift for a friends birthday. however, i'm facing some problems. the kit that i bought came with a burr brown OPA277P. when i tried it, theres no sound at all. so i tried rolling with the other op-amps that i own. tried the JRC 4556AD and National LM4562. the music does come on, on both channels, however, the vocals seemed suppressed. its like those karaoke machines that try to delete the voice recording on songs. normally, the 45556AD and LM4562 work perfectly on my RA1 clone. but that runs on 18V power supply. so i'm wondering if you guys know what could be the problem? is it due to the op-amp/other components? if its an op-amp problem, where can i get one fast? and i do not have a multimeter cause i lent it to someone. thanks lots! Share this post Link to post Share on other sites
heady 0 Report post Posted January 3, 2009 Try applying your hot soldering iron to every solder point on the pcb to refresh the solder joints. Your problem sounds like a cold joint some where. Share this post Link to post Share on other sites
feesh 0 Report post Posted January 4, 2009 okay it works now, thanks heady! much appreciated Share this post Link to post Share on other sites
Duck-in-the-Box 0 Report post Posted January 4, 2009 so its because of cold joint? Share this post Link to post Share on other sites
heady 0 Report post Posted January 4, 2009 okay it works now, thanks heady! much appreciated You are welcome. Share this post Link to post Share on other sites
feesh 0 Report post Posted January 5, 2009 so its because of cold joint? yeah haha. the connection on the input jack to the ground wasnt soldered properly. Share this post Link to post Share on other sites
