I could use some suggestions I have 4 of these boards that have a static sound present on the 40hrz output when a sub is hooked up the the board. The amp works but just sounds off, like static is present.
What component(s) would cause this. Opamps or inductor? Some suggestions would be helpful as I have changed a few componts already and it made little difference.
What component(s) would cause this. Opamps or inductor? Some suggestions would be helpful as I have changed a few componts already and it made little difference.
Attachments
Is it static or a whining sound of varying frequency like this:?
http://www.bcae1.com/temp/cooleditmixedoscillator01.wav
http://www.bcae1.com/temp/cooleditmixedoscillator01.wav
Perry do you have an extact part number for mouser for the driver chips 74HC02D? I may have the wrong ic as everyone i replace never seems to work.
Hey Rob
I can get some scope pictures for you tomorrow on the inputs of the logic gates if that will help. Shoot me a text if there is anything else specific you are needing info on. There is not much involved in the output that could introduce static. Do you see the static on the scope when probing the output? Also as Perry said is the input clean?
It is much easier to work with these boards if you use ribbon cable and headers to be able to have the board flat while probing with the scope if you suspect logic problems.
These IC's are a little sensitive to high ESD so I do suggest an ESD strap when handling and installing them.
I can get some scope pictures for you tomorrow on the inputs of the logic gates if that will help. Shoot me a text if there is anything else specific you are needing info on. There is not much involved in the output that could introduce static. Do you see the static on the scope when probing the output? Also as Perry said is the input clean?
It is much easier to work with these boards if you use ribbon cable and headers to be able to have the board flat while probing with the scope if you suspect logic problems.
These IC's are a little sensitive to high ESD so I do suggest an ESD strap when handling and installing them.
Ok Great i ordered some jumpers. I always seem to have problems witih these amps if the output section driver is damaged. I do not think that i was installing the proper ic. So i ordered the correct version. And the Aduino jumpers.
74HC02D an NXP i dont have the exact part number to them any longer. Just they never seem to work for me if i replace them. So i ordered, 595-SN74HC02DR mouser part number.
How did they not work correctly? I've seen a few ICs that wouldn't work properly when used as an oscillator (triple inverter oscillator and similar) but these simply pass the signal.
I bought 3 of these boards 2 months ago. Two with the ps fried and 1 with bad outputs. 2 working now with no major problems than 6n137 replacement.
If you have 4 boards with the same noise, try with another rca cable, another audio-signal player, etc.
In another amps i had fixed with the 02 logic ic, when it is bad the output have dc voltage.
If you have 4 boards with the same noise, try with another rca cable, another audio-signal player, etc.
In another amps i had fixed with the 02 logic ic, when it is bad the output have dc voltage.