Channel switching

[jestaudio]

i could do with a bit of advice,ive implemeted channel switch on a dpdt realy shunting the signal to earth fo the unused channel, i have a problem with audible click when the relay operates, its pretty loud
Any suggestions on getting over this, the sytem is based around the dumble syle switching

[rdjones]

i could do with a bit of advice,ive implemeted channel switch on a dpdt realy shunting the signal to earth fo the unused channel, i have a problem with audible click when the relay operates, its pretty loud
Any suggestions on getting over this, the sytem is based around the dumble syle switching

1. Make sure there's no DC on the relay contacts.
2. Use a high value "damper" (2M - 10M)* resistor across the contacts to bleed off any residual charge.

rd

* M=1,000,000

[Structo]

Do you also have a diode across the coil of the relay?

[jestaudio]

Do you also have a diode across the coil of the relay?

Yep, i pretty much lifted the switching sytem from the dumble layout i used for my od50

[jestaudio]

i could do with a bit of advice,ive implemeted channel switch on a dpdt realy shunting the signal to earth fo the unused channel, i have a problem with audible click when the relay operates, its pretty loud
Any suggestions on getting over this, the sytem is based around the dumble syle switching

1. Make sure there's no DC on the relay contacts.
2. Use a high value "damper" (2M - 10M)* resistor across the contacts to bleed off any residual charge.

rd

* M=1,000,000

Is that across the coil or across the switching contacts

[John_P_WI]

Across the contacts.

[d95err]

A schematic would be helpful, to see where in the circuit the relays are placed (draw a simple one on paper, take a foto and post).

[jestaudio]

A schematic would be helpful, to see where in the circuit the relays are placed (draw a simple one on paper, take a foto and post).

I think i,ve gone about it the wrong way, if i,m correct just shunting the channel to ground should mute the channel, what i have tried is swirching the hot signal between channels rather than powering both channels and grounding the unused channel

[d95err]

Shunting to ground is always the quietest way to switch things, but not always possible to do, depending on the topology of the amp. Lots of amps switch the hot signal without problems. You should try to switch the signal as late in the signal chain as possible, to make sure relay noise is not amplified more than necessary.

You might also want to look at the grounding of the relay coil circuit. Make sure it is separated as much as possible from signal grounds.

[jestaudio]

Shunting to ground is always the quietest way to switch things, but not always possible to do, depending on the topology of the amp. Lots of amps switch the hot signal without problems. You should try to switch the signal as late in the signal chain as possible, to make sure relay noise is not amplified more than necessary.

You might also want to look at the grounding of the relay coil circuit. Make sure it is separated as much as possible from signal grounds.

i,ve managed to reduce the noise to a acceptable level, not totallt silent but close, i,ve used a couple of 5.1 m resistors across the contacts which seems to have done the trick, be nice if i got it totally silent so anymore suggetions would be great