Supergun 'hum'

A couple of months ago I bought a ready-made supergun off Ebay.de (its called MAK) - it works great, except for one thing, there is an annoying 'hum' coming out of the TV's speakers, and strangely enough, the more 'white' there is on the screen, the louder this hum is. I tried it with 3 different TV sets, different models, and they all gave me the same annoyance.

Roll on a few months, so I decide to make my own supergun - I have checked out howtos etc., and followed instruction, and my new supergun works great... except ... yes, there is a hum again!

Anyone ever experienced this? This is very frustrating and I cannot find a way to fix it

I would appreciate any help - Thanks in advance!

Got a pic of it? Or the eBay listing?

More or less it looks like this:



I dont want to 'fix' this supergun though, but rather, the one I made... The weird thing for the hum (which is present on both superguns) is the fact that it increases accodring to the amount of white on screen - if the screen is total black, there is NO HUM. Maybe someone more technical than me can come up with a sensible explanation - and of course, a solution

Unusual that the hums made by both, it could well be your TV.Try it on another?
Quality of your scart perhaps?

I tried on 3 different TV sets... same results. I have also used different scart cables.

Many TVs do a humming noise when there's a lot of white in the picture. Check if it does it even when no superguns/consoles are connected to it.

Just checked out my Wii.... lots of white, no hum at all

Update: It seems that the culprit is a scart extension cable I am using. The hum is gone on the MAK supergun thingy...

Unfortunately my own supergun still produces a hum dependant on the amount of white on screen. Any ideas?

Did you use the same ground for audio and video, like daisy chain it or same point? Sometimes it does that if you do. Use 2 different ground points for video and audio.