Hey all,
I made a TDA7292 amplifier circuit by the book. Used star grounding separated out from the PCB. I have used the same PSU setup to test LM3886 and it worked perfectly fine.
When playing music whenever a deep bass note comes the amp output locks to -10 to -15Vdc. I noticed a pop and the sound would start to clip. Then I noticed my speaker driver heating up which has never happened before. I then measure the current and voltage and realized there's a DC offset at the output. I checked the input as much as I could but cant find any way a DC input could happen.
Here are the deets:
+/- 24Vdc from two SMPS connected in series with reverse diodes (the same setup worked for LM3886)
Designed for 16ohm load, tested at 8ohms too - the issue persists
Used some input RC filtering to cap lower and upper frequencies
Signal and Power grounds are connected outside of the PCB
The issue does not occur at very low overall volumes
Ive checked all the ground connections, all seem okay. The audio cable seems to be fine too.
Ive soldered 3 different boards with IC's purchased from Digikey and a local source (probably a copy) all have the same issue. I suspect something in my design is wrong but cant figure it out.
I made a TDA7292 amplifier circuit by the book. Used star grounding separated out from the PCB. I have used the same PSU setup to test LM3886 and it worked perfectly fine.
When playing music whenever a deep bass note comes the amp output locks to -10 to -15Vdc. I noticed a pop and the sound would start to clip. Then I noticed my speaker driver heating up which has never happened before. I then measure the current and voltage and realized there's a DC offset at the output. I checked the input as much as I could but cant find any way a DC input could happen.
Here are the deets:
+/- 24Vdc from two SMPS connected in series with reverse diodes (the same setup worked for LM3886)
Designed for 16ohm load, tested at 8ohms too - the issue persists
Used some input RC filtering to cap lower and upper frequencies
Signal and Power grounds are connected outside of the PCB
The issue does not occur at very low overall volumes
Ive checked all the ground connections, all seem okay. The audio cable seems to be fine too.
Ive soldered 3 different boards with IC's purchased from Digikey and a local source (probably a copy) all have the same issue. I suspect something in my design is wrong but cant figure it out.
