slow ramp up and down for switching phantom

[mrd]

Hi,

I am looking for a circuit to ramp up and down phantom power when it is switched on and off.

So far the closest circuit I have found is the attached one. Works fine on the sim. However, I can't really fit a 50V cap in there, so am wondering if you have any ideas for a different circuit, with a lower voltage cap. The smaller part size the better, as I'm modding it so most of the parts go under a pcb so I have about 6mm clearance.


It's to avoid the 'pop' sound and current surge caused when its switched on.

 

[ericgibbs]

Hi,

I am looking for a circuit to ramp up and down phantom power when it is switched on and off.

So far the closest circuit I have found is the attached one. Works fine on the sim. However, I can't really fit a 50V cap in there, so am wondering if you have any ideas for a different circuit, with a lower voltage cap. The smaller part size the better, as I'm modding it so most of the parts go under a pcb so I have about 6mm clearance.


It's to avoid the 'pop' sound and current surge caused when its switched on.

hi,
What is the actual voltage required by the microphone when its working.
I would look at FET's in place of the BJT's and smaller caps are feasible.

 

[mrd]

48V (+ or - 4V) is what's specified on most I think.

Thanks, yeah I thought maybe FETs would be more appropriate. Though not sure on how well they like turning on slowly? I'll have a play

 

[imix500]

I'm not sure you can lessen the "pop" from the preamp stage phantom powers. There are already current limiting resistors that bring up the preamps fairly slowly. The pop is just the preamp stabilizing. It doesn't hurt the console, just don't have the channel open when switching on. But, you can't really hurt anything by trying.