I have a little problem with my two MV692 mics.
I got two little conversion PCB's from a nice member here. He is an electronic engineer.
The circuit is similar to the one Gefell uses in their conversion but it has an ATL431 shunt regulator instead of the VD21 Zener Diode where the REF pin goes to two resistors. One 39k Ohm resistor which goes to + of C9 and one 10k Ohm resistor which goes to ground. And instead of a 22uF cap there is only a 2.2uF cap.
After some really frustrating work on these mics I now have two "working" mics but with a rather high background noise which sounds like white noise.
I replaced the two 1uF elkos (C8 & C9) with 3.3uF ones and the 10uF elko (C11) with a 22uF.
The noise is not affected by the pad switch.
I also tested different capsules so that is also not the culprit.
In one mic I also removed the three 22nF caps of the Low Cut filter because I wanted to change them for C0G caps but did not yet. If I switch the Low Cut on that one the noise is still there although the output signal is cut off because of the missing caps.
Does anybody have a clue how the noise can be on the output even if the signal is cut off?
Is it safe to say, that the voltage regulator is the cause of the noise?
I got two little conversion PCB's from a nice member here. He is an electronic engineer.
The circuit is similar to the one Gefell uses in their conversion but it has an ATL431 shunt regulator instead of the VD21 Zener Diode where the REF pin goes to two resistors. One 39k Ohm resistor which goes to + of C9 and one 10k Ohm resistor which goes to ground. And instead of a 22uF cap there is only a 2.2uF cap.
After some really frustrating work on these mics I now have two "working" mics but with a rather high background noise which sounds like white noise.
I replaced the two 1uF elkos (C8 & C9) with 3.3uF ones and the 10uF elko (C11) with a 22uF.
The noise is not affected by the pad switch.
I also tested different capsules so that is also not the culprit.
In one mic I also removed the three 22nF caps of the Low Cut filter because I wanted to change them for C0G caps but did not yet. If I switch the Low Cut on that one the noise is still there although the output signal is cut off because of the missing caps.
Does anybody have a clue how the noise can be on the output even if the signal is cut off?
Is it safe to say, that the voltage regulator is the cause of the noise?
