Velleman MK171: Voice Changer Making Constant Screeching Noise

Thread Starter

Vulkan

Joined Aug 16, 2018
6
I recently purchased a Velleman MK171: Voice Changer. I have done a few soldering projects before with no problems, but the voice changer, when turned on, just makes a screeching noise through the speaker. The Led does not respond to sound, but when it is making screeching noises it's always lit up. I believe all the parts are installed in the correct orientation (no polarity problems). I have resoldered the speaker and a few parts that looked like they could be done better. (My equipment is now very low quality as someone had been melting plastic and foam with it, but the circuit still lights up so I don't think it was the equipment's fault.) I am trying to install the voice changer into a Wrench style mask based on Watch_Dogs 2. I honestly have no idea what the problem could be. Thanks in advance!
 

Sensacell

Joined Jun 19, 2012
2,634
Are you sure it's not just the physical configuration inside the mask that is causing the problem?
Feedback between mic and speaker?

Connect the speaker terminals to an external speaker located some distance away, observe the difference.
 

Thread Starter

Vulkan

Joined Aug 16, 2018
6
I haven't even installed the voice changer into the mask yet. It is still just the PCB wired to a speaker (With the battery connected of course) and the speaker already some distance away. (The speaker has not been fully connected yet; the wires are just wrapped around the ports.) Even when my room is completely silent, as soon as I turn it on and connect the wires to the speaker, painfully loud screeching starts coming out of the speaker. There's nothing to feedback because there isn't any noise in the first place. (Even when I hook up the speakers and then turn the module on, it begins screeching)
 

Thread Starter

Vulkan

Joined Aug 16, 2018
6
RV2 being the volume dial, yes. It still screams just slightly quieter. Give me one minute to finish soldering the speakers and the whole PCB back together.
 

Thread Starter

Vulkan

Joined Aug 16, 2018
6
New update: I resoldered the speaker to the ports and the screeching has stopped (I still don't know why), but now the voice, when sensitivity and volume are turned all the way up is still fairly quiet. (Around the same volume as my speaking. Is this normal, because this could be a problem as the speaker in my mask is kind of concealed and therefore muffled.
 

Thread Starter

Vulkan

Joined Aug 16, 2018
6
OH MY GOSH! YES! I GOT IT! FINALLY! I've been trying for two weeks, and I finally figured it out. It was a combination of the wiring for the battery and the speaker. The speaker's wires had this really weird orientation that they had to be put in for the sound to not be all screamo and the battery wires were partially blocked by the solder, which for some reason stopped the battery from fully powering the circuit. Now it works! Thanks for your guys' help. I really appreciate it.
 
Last edited:
Top