k8030

Kits Home Projects
1

Hi, I have a question about k8030.

If you try to record sth. from a distance, the input record noise amplitude is so small, that you can’t hear anything while playback. So I am wondering how could I amplify the input signal?

I’ve tried to connect the output of the MK136 on the k8030 mike pins and it worked perfectly at first, but now it’s suddenly making strange noises while playing back. I didn’t damage anything, though, because when I remove MK136 and record things normally, everything works fine.

Any ideas how to amplify the signal or why in the combination with MK136 the circuit is acting strange? (when I play the message amplified by mk136, loud and continuous “knocks” (like knocking on the door) are heard from the loudspeaker; even when I record in complete silence!)

Thanks,
Michel

2

No no…this will not work.
The input is made only for an electred mic. If you need an aux input, you need to modify the circuit (you can search the datasheet from the chip).
For normal use, please use the incl. mic.

3

Hehe…it works! With mk136. I just had to place a resistor on the pins too. Headphones are already good enough (17 ohms).

I’ll post later with which resistance the circuit performs best.

:smiley:

4

Hehe, it doesn’t work actually. I guess the mike was badly soldered and when I put on the mk136, I accidentally fixed it. It works fine now without mk136 which doesn’t improve anything.
:smiley: