6v DC Wall adapter introducing thin black lines into video signal

technical questions/help
1

Hi guys,

I have a composite glitch effect unit that originally runs on 4 AA alkaline batteries. I’m trying to change the power source to a 6V 2A DC wall outlet adapter. I tested the power adapter, confirmed the voltage was correct and soldered the positive and negative wires to the positive and negative wires attached to the battery compartment terminals (positive to positive, negative to negative, de-soldered it from the battery compartment terminals, and covered the exposed wires with slip on wire sheathing).

The unit works as it had but now some thin black lines have been introduced to the video signal. Just looking to see if anyone has experienced this and if they had found a solution. Wondering if this is due to noise interference and could be resolved by adding a ferrite clip to the power wire.

I can add examples of the issue or wiring if necessary.

Thanks in advance

2

it’s to do with the PSU introducing noise. You might improve it with a ferrite core, but it’s advisable to use a different adapter. The device likely uses 5v if it’s powered by 6v battery.

Check for a 5v regulator inside the device. If it uses one (LM7805) then you can use a higher voltage psu. (only up to 9v is advisable though).

This would give you more options to find a noise free supply.

I used a laptop PSU for an audio effect, it worked great. But a different laptop supply made a high pitched whine all over the audio.