Plecto
Full Member level 5
I've made several cmoy amps on a breadboard without any problems at all, but it refuses to work when I solder it to a prototyping board. The amp as it is now has a constant hissing noise with difference electrical sounds seemingly coming and going at random, but the sounds do change in intensity if I touch or move the amp. The constant hissing noise increases and decreases in intensity if I move my hand closer or further away from the amp (I didn't think that was possible). When it comes to the actual music I'm trying to amplify this also varies alot, something not beeing there at all or it can be heard quite well (allthough the sound quality is pretty bad), but it is usually very weak in the background of all the other noises.
I've made two completely independant amps with about the same problems in both of them. I got a new temperature controlled soldering iron yesterday and with a seperate container for flux, resin cored solder and a wet sponge my solderings are pretty good so there shouldn't be any bad connections. I have also gone over the solderings several times to make sure everything is as it should be. The measures I have taken is to completely bypass the input cap, remove the volume pot and changed the batteries (running it off two 9V batteries) with no differences.
This is the schematic I have followed. The power supply caps are 330uF (not 220uF) and the amps I have tried are Op275 and NE5532R (same result).
https://tangentsoft.net/audio/cmoy-tutorial/misc/cmoy-tangent-sch.pdf
I've made two completely independant amps with about the same problems in both of them. I got a new temperature controlled soldering iron yesterday and with a seperate container for flux, resin cored solder and a wet sponge my solderings are pretty good so there shouldn't be any bad connections. I have also gone over the solderings several times to make sure everything is as it should be. The measures I have taken is to completely bypass the input cap, remove the volume pot and changed the batteries (running it off two 9V batteries) with no differences.
This is the schematic I have followed. The power supply caps are 330uF (not 220uF) and the amps I have tried are Op275 and NE5532R (same result).
https://tangentsoft.net/audio/cmoy-tutorial/misc/cmoy-tangent-sch.pdf