Is there a dedicated thread for the Pass power relay kit that is in the DIY store? Did multiple searches but could not find anything.
My Q: can a LED and associated current limit resistor be easily added (with minimal additional components) that would show either output is muted or show output is functioning? LED need not show both states; one state or the other is sufficient (will just change color of annunciation LED). Relay has only two poles, so cannot use one pole to turn on/off an LED as both poles are needed for stereo use.
My Q: can a LED and associated current limit resistor be easily added (with minimal additional components) that would show either output is muted or show output is functioning? LED need not show both states; one state or the other is sufficient (will just change color of annunciation LED). Relay has only two poles, so cannot use one pole to turn on/off an LED as both poles are needed for stereo use.
It looks like this circuit is used to short the output of an amp to ground at turn on/off.
When the relay is energized, the short is removed and the amp plays music.
You could easily botch on a LED and a resistor where R10 goes to indicate that the amp plays music.
Not sure, if I like shorting an amps output. I'd rather use proper speaker relays like the Amplimos and make or break the connection to the speakers.
Maybe there is more Info in the V-Fet thread:
V-Fet
Happy building
When the relay is energized, the short is removed and the amp plays music.
You could easily botch on a LED and a resistor where R10 goes to indicate that the amp plays music.
Not sure, if I like shorting an amps output. I'd rather use proper speaker relays like the Amplimos and make or break the connection to the speakers.
Maybe there is more Info in the V-Fet thread:
V-Fet
Happy building
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when amp is powered off, output cap is empty
when amp is powered on, inside end of output cap is abruptly going to U/2 and relay is shorting the speaker to establish current path for that and protect speaker from same
when amp is powered on, inside end of output cap is abruptly going to U/2 and relay is shorting the speaker to establish current path for that and protect speaker from same
My limited understanding lets me come to this conclusion - could be wrong though:
Q2 + C7 ensures delayed on of relay = preventing turn on thump (base takes a while to get positive enough on turn on)
Q1 +C7 ensure early relay off = preventing turn off thump (base voltage falls slower than supply voltage and is quickly not negative enough on turn off)
Q2 + C7 ensures delayed on of relay = preventing turn on thump (base takes a while to get positive enough on turn on)
Q1 +C7 ensure early relay off = preventing turn off thump (base voltage falls slower than supply voltage and is quickly not negative enough on turn off)
Thank you so much, including your diagram showing where the LED can be added.It looks like this circuit is used to short the output of an amp to ground at turn on/off.
When the relay is energized, the short is removed and the amp plays music.
You could easily botch on a LED and a resistor where R10 goes to indicate that the amp plays music.
Not sure, if I like shorting an amps output. I'd rather use proper speaker relays like the Amplimos and make or break the connection to the speakers.
Maybe there is more Info in the V-Fet thread:
V-Fet
Happy building
I'm using this to mute a preamp, so no problem shorting output to ground.
