🙂 not going to argue on that with anyone.
use no resistor if you think it is correct. and advise it.
i prefer an another solution, and will advise that.
use no resistor if you think it is correct. and advise it.
i prefer an another solution, and will advise that.
The power amp in question is a non-inverting LM3875, configured in dual mono (a transformer and pair of diode bridges per channel, with a 10uF cap across the output of each bridge).
When powered up and no input connected it is virtually silent.
When powered up and no input connected it is virtually silent.
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OK, so for this to be truly silent (as in no clicks or thumps) as the series connected relay operates, means that at the instant the relay closes (after the power on delay) that the voltage differential between each side of the relay must be zero.
And that should happen... when the preamp is powered up its output will be some DC value (that spike that you measure) that falls very quickly to around zero volts. The input to your chip amp is shown as DC coupled, so taking that at face value, the input to the chip amp is also at zero volts DC. Result when the relay closes... silence. The same happens when it opens because that occurs whilst the rails are still collapsing. That means that the preamp output is still held at zero volts for long enough until the relay disconnects.
So you should be good to go 🙂
And that should happen... when the preamp is powered up its output will be some DC value (that spike that you measure) that falls very quickly to around zero volts. The input to your chip amp is shown as DC coupled, so taking that at face value, the input to the chip amp is also at zero volts DC. Result when the relay closes... silence. The same happens when it opens because that occurs whilst the rails are still collapsing. That means that the preamp output is still held at zero volts for long enough until the relay disconnects.
So you should be good to go 🙂
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