Hi there!
I have some very basic electronics knowledge, but can't work out how to fix a problem I am having.
I put together an amplifier (based off a d-class AA-AB32189). It is powered off its own 36v dc transformer, and there is a second transformer powering a pre-amp and an input selector (for Bluetooth and 2x rca - one off to a phono pre-amp). I have just sketched up a very basic map of the setup and will attach bellow.
There is also a wifi switch in-front of the two transformers that I can use my google assistant to turn the unit on and off.
I love the system, it works and sounds great. However, I get a loud pop a few seconds after turning it off. I have a work around with a switch that I can use to turn the amp off first, then shut the rest down. But this kind of ruins the point of the Wifi switch as I still have to go to the unit to turn it off!
I am looking for a solution to fix this pop. I assume it is from the other circuits (preamp and selector) turning off before the amp, so need a way to either delay these units turning off by 2-3 seconds so the amp can go off first (some kind of large capacitor?) or by instantly muting the amplifier when the power is turned off.
The amp has an input for a mute switch, so I was thinking if there was a way that this switch could be triggered by the loss of the 240v ac coming out of thew wifi switch this could work?
I have read an easy solution can be a cap on the amp which drains it so it shuts down quicker, but not sure If i can add this to a D-class amp?
Sorry if this is convoluted, but I would really appreciate some help on how to overcome this ! I have read a few thing but not found a solution that makes sense. And I dont know how I can get the loss of AC to trigger a small on of switch (I know relays can trigger 240v via 12v but can they go the other way?)
Thanks in advance!
I have some very basic electronics knowledge, but can't work out how to fix a problem I am having.
I put together an amplifier (based off a d-class AA-AB32189). It is powered off its own 36v dc transformer, and there is a second transformer powering a pre-amp and an input selector (for Bluetooth and 2x rca - one off to a phono pre-amp). I have just sketched up a very basic map of the setup and will attach bellow.
There is also a wifi switch in-front of the two transformers that I can use my google assistant to turn the unit on and off.
I love the system, it works and sounds great. However, I get a loud pop a few seconds after turning it off. I have a work around with a switch that I can use to turn the amp off first, then shut the rest down. But this kind of ruins the point of the Wifi switch as I still have to go to the unit to turn it off!
I am looking for a solution to fix this pop. I assume it is from the other circuits (preamp and selector) turning off before the amp, so need a way to either delay these units turning off by 2-3 seconds so the amp can go off first (some kind of large capacitor?) or by instantly muting the amplifier when the power is turned off.
The amp has an input for a mute switch, so I was thinking if there was a way that this switch could be triggered by the loss of the 240v ac coming out of thew wifi switch this could work?
I have read an easy solution can be a cap on the amp which drains it so it shuts down quicker, but not sure If i can add this to a D-class amp?
Sorry if this is convoluted, but I would really appreciate some help on how to overcome this ! I have read a few thing but not found a solution that makes sense. And I dont know how I can get the loss of AC to trigger a small on of switch (I know relays can trigger 240v via 12v but can they go the other way?)
Thanks in advance!
Attachments
Sounds like you could use only a separate 240V relay (make sure coil is meant for 240V and not 12 or 24 etc.). You only connect relay coil to 240V. The secondary you can wire however you need, is it to ground or 12V, depending on how your mute input works.
For a more complex solution this circuit works well, but isn't meant for full 230V AC: Simple Universal Speaker Delay Using A Triac
For a more complex solution this circuit works well, but isn't meant for full 230V AC: Simple Universal Speaker Delay Using A Triac