Richon

Is it normal: phantom voltage slowly decreasing after turning it of? (GREEN PRE)

it seems that it goes tooo slow down. First as I turn the phantom off, it goes to cero. Later it comes back (after 2 seconds) on 16V and start goind slowly down, till it goes to cero

so i'm kind of scared to connect my ribbon mic (obviously without phantom "on") taking notice of the remaining voltage goind inside the Green Pre.
watch my Blog for DIY tube amps, effects at www.richon-caster.blogspot.com


PRR

Connect 47K from "+48V", after the switch, to ground. Check turn-off again.

If an electrolytic capacitor is charged then "drained", then left with NO load, it can "bounce back". There is a very small charge stored deep in the chemistry. Enough to read on a high-impedance volt meter, not enough to hold a 47K resistor at significant voltage.

Richon

connect it just before the 100 ohms resistor after the switch in the phantom part of the GREEN PRE PCB?
watch my Blog for DIY tube amps, effects at www.richon-caster.blogspot.com

Richon

bump
watch my Blog for DIY tube amps, effects at www.richon-caster.blogspot.com

PRR

> bump

Yes.

Richon

would the 47k resistor act like a "resistor bleeder" (is 1/4 watt right for the resistor, or should it be 1/2W??)????
watch my Blog for DIY tube amps, effects at www.richon-caster.blogspot.com


 

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