I recently built a stereo amp using this chip.
The problem is when I power it up i hear the 60hz in the speaker. There was a large pop through the speakers at power on im guessing this is from the caps.
At first there was no sound so i turned it off, That was a mistake i heard the awfullest whirring noise which probably ruined my tweeters. experienced this whole routine a second time then i decided to unplug everything and out of frustration i tried one more time. amazing i could barely hear the music as it played it got louder and louder but it was still heavy with ac distortion.
Now heres the interesting bit.
When i turn the power off the distortion goes awayand it plays the music perfectly for about 10 seconds (prolly the caps discharging)
Also upon initial testing there was -4.53 volts DC ON THE OUTPUT! just on the right channel so no testing was done to that channel.
Ive uploaded the power supply schematic and one channel schematic as they appear on headwize. Ive also uploaded a picture of one solderboard with its 10000uf cap for size comparison. I followed the general rule for gainclone keep everything as close as possible aside from the tranny
The problem is when I power it up i hear the 60hz in the speaker. There was a large pop through the speakers at power on im guessing this is from the caps.
At first there was no sound so i turned it off, That was a mistake i heard the awfullest whirring noise which probably ruined my tweeters. experienced this whole routine a second time then i decided to unplug everything and out of frustration i tried one more time. amazing i could barely hear the music as it played it got louder and louder but it was still heavy with ac distortion.
Now heres the interesting bit.
When i turn the power off the distortion goes awayand it plays the music perfectly for about 10 seconds (prolly the caps discharging)
Also upon initial testing there was -4.53 volts DC ON THE OUTPUT! just on the right channel so no testing was done to that channel.
Ive uploaded the power supply schematic and one channel schematic as they appear on headwize. Ive also uploaded a picture of one solderboard with its 10000uf cap for size comparison. I followed the general rule for gainclone keep everything as close as possible aside from the tranny
Attachments
i have 5.1k 5k 220k 4.7k 3.2k 330k. I dont guess any of these will suffice.
my last post didnt show up so im going to retype it.
the original design had a coupling cap on the preamp which i had overlooked. I have some spare ones that are 150uf way over the 3.2uf specified.
will this fix the static because it really does sound like 60hz ac hum whether the source is connected or not. and theres still the dc issue on the right channel.
I figured out why the third power on was the charm. if the source isnt connected when the amp is turned on and you plug the source in nothing comes out but if the source is connected while the power is off and then turn it on the sound comes out along with the very very loud buzz thats present if its plugged in after power on.
also as i turn the volume on the pc up the static gets worse and a large popping starts occuring every second or so.
my last post didnt show up so im going to retype it.
the original design had a coupling cap on the preamp which i had overlooked. I have some spare ones that are 150uf way over the 3.2uf specified.
will this fix the static because it really does sound like 60hz ac hum whether the source is connected or not. and theres still the dc issue on the right channel.
I figured out why the third power on was the charm. if the source isnt connected when the amp is turned on and you plug the source in nothing comes out but if the source is connected while the power is off and then turn it on the sound comes out along with the very very loud buzz thats present if its plugged in after power on.
also as i turn the volume on the pc up the static gets worse and a large popping starts occuring every second or so.
I used some alligator clips to add the 220k resistor on the channel that works with the distortion. when i add those no matter what i do its just silent. no hum or anything unless i pull the source rca jack and then it gives me a mild pop.
would the protection mode cause the dc on the right channel im seriously thinking that chip was damaged or not manufactured right. but ill worry about that one once i get the left channel working correctly. ill try the lower value resistor and report back.
would the protection mode cause the dc on the right channel im seriously thinking that chip was damaged or not manufactured right. but ill worry about that one once i get the left channel working correctly. ill try the lower value resistor and report back.
Oh i thought you said it was only the right channel.
I ran into a problem with proto typing with perfboard. Its fairly soft stuff, and seems to love moisture. I had a circuit fail on me because of leakage current due to slightly damp perfboard.
Has it been high humidity where you have been working?
Do you have an oscilliscope?
I ran into a problem with proto typing with perfboard. Its fairly soft stuff, and seems to love moisture. I had a circuit fail on me because of leakage current due to slightly damp perfboard.
Has it been high humidity where you have been working?
Do you have an oscilliscope?
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