Relay delay

[Ted205]

Sorry for the newbie question.

Looking to implement a delay to the preamp output to avoid pops on start up.

I'm trying to use a simple 555 timer. I've simulated this:


theory says this should work. But in the simulation doesn't.

Am i being stupid ?

[Nuuk]

Not sure about your circuit Ted but this one on Decibel Dungeon works fine, and you can vary the delay to suit different pre amps/buffers.

[CJ900RR]

I seccond that. Nuuks solution works like a charm

[Ted205]

so the version on dd starts high and goes low after x seconds?

as this is how i have it working on bread board


the schematic of the circuit in multisim:

but it does work as it does in the real world. or am i being stupid?

i want to integrate it into my psu pcb so would like to be able to sumulate and route it

[Nuuk]

Ted, why the PSU?

[Ted205]

turns out it was just the software settings working ok now (set initial conditions to zero)

i want to use it in the psu to switch the power amp V+ and V- on after a short period (i.e after power has been applied to the buffer and allowed it to settle)

[Nuuk]

I still think that is is better to mute the audio out from the buffer until it has settled but good luck anyway.

[Ted205]

its a work in progress, just trying to keep the signal path free :P.

Thanks for the circuit btw.

[Nuuk]

But that is the point of the design shown on DD, ie it is not in the signal path.

[Ted205]

i read it that the relay shorts the buffer output to ground for a short period while the power is applied to it. I was planning to switch the power amp section on after the buffer has settled.