Does anyone have the schematics for this 4 channel amp? I can't find anything on the internet. It is identical to another model (king sound eca-504). It was going in protection mode, I repaired a broken solder connection and a blown transistor and seems to work now. However, when connecting the sub in bridged mode (channels 3 and 4, since 1 and 2 have the LPF broken) it's almost inaudible (the other stock speakers cover its sound). This is strange, because if I unplug one channel from the inputs it starts to be louder.
I tested the output channels individually at home with an oscilloscope (but with no load as I don't have any) and I get the same input wave (amplified) in all of them. I also checked the rails where I can see +/- 20V steadily.
What else could I check?
I tested the output channels individually at home with an oscilloscope (but with no load as I don't have any) and I get the same input wave (amplified) in all of them. I also checked the rails where I can see +/- 20V steadily.
What else could I check?
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It appears that the signal isn't being inverted for the negative channel of the bridged pair of channels.
The crossover shouldn't determine whether it can be bridged or not. Try both pairs of channels to see if they play normally in any crossover position when bridged.
Also try using only one input for both pairs. Try only the left and only the right for both pairs.
What's your signal source?
The crossover shouldn't determine whether it can be bridged or not. Try both pairs of channels to see if they play normally in any crossover position when bridged.
Also try using only one input for both pairs. Try only the left and only the right for both pairs.
What's your signal source?
when testing in the car, the problem was there for both pairs. Now I tried on the oscilloscope to see if the signal is being inverted, and it looks like it is. The first picture is channel 3 only; the second channel 3 and 4, and the last one channel 1 and 2. I don't know if I'm missing something.
At home, I'm using an android smartphone with a signal generator app. In the car, the signal comes from the stock headunit, passing through a cheap no-brand loc.
At home, I'm using an android smartphone with a signal generator app. In the car, the signal comes from the stock headunit, passing through a cheap no-brand loc.
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Well, that is indeed possible now that I think about it. An rca broke, and now there is another one (unsoldered) connected to the cable. I'll do some checks.
Thanks a lot for your help.
Thanks a lot for your help.