Hi have a DIY request from a friend, he wants a specific Bbox designed for DPA4061 but he wants to run into mic-in on his PCM-M1 Dat.
After discussing that point, I think he needs some attenuators at the mic-in input, and I thought I could build some attenuator in this DIY DPA bbox:
I've reading this article:
http://www.uneeda-audio.com/pads/ but I cannot figure out which could be the perfect solution in order to build the attenuator in the BBox.
Maybe adding a solution like this (paging:
http://www.epanorama.net/circuits/line_to_mic.html)
20 dB PAD for line to electret microphone input
This circuit is designed to interface consumer (-10 dBu) signals to microphone input that is designed for two-were electret microphone capsules. This circuit provides around 20 dB of signal attenuation (typically enough to make thigns work, if more attenuation is needed use higher R1 value) and blocks the DC bias used in the electret microphone input to get to the line signal side (C1 does this). This circuit look like around 1 kohm signal source to at the mic side, whic matches pretty well to electret capsule characteristics (similar impedance and provides DC path for bias to go to ground).
C1
+Line level in --||----R1-----.-- +Mic level output
+ |
|
.----R2---.
|
Ground (input)----+--------------- Ground (output)
R2 = 1 kohm
R1 = 10 kohm
C1 = 10 uF
Any help will be appreciated.
Thanks!