Tech Sound Help Pls.

Fents · Post by **Fents** » Tue Jun 28, 2005 5:10 pm

OK I have a sound issue problem with my setup at home...

Who knows this one cause its freakin weird...

When i turn my setup on (decks, mixer, amp, speakers) and i have NOTHING playing theres a hiss sort of sound....its real quiet but that aint the prob.

When i have nothing playing and i touch the VOLUME knob on my amp (old valve amp with a crossover for bass trebble and vol etc) i get a radio signle...sounds like some AM crap...and if i take my hand off it stops. This amp/crossover does NOT have a tuner in it whatsoever. Its purley to run stuff through..

And NO i havnt been smoking crack.!

Anyone?

ukime · Post by **ukime** » Tue Jun 28, 2005 5:13 pm

You might be acting as an antennae to pick up the radio signal and somehow it's feeding into the amp when you touch the volume knob? (which will have some sort of connected circuit running to your monitors?)

You know, like the crazy people picking up radio in their fillings

Fents · Post by **Fents** » Tue Jun 28, 2005 5:16 pm

So what do i do to fix?

ukime · Post by **ukime** » Tue Jun 28, 2005 5:18 pm

depends how long it's been happening / what is really causing it.

if you've used a "bunny-ears" antenna for television, you might notice when you go and hold the antenna, the reception is better ... basically because you're being used to pick up the signal, even being close to it helps to draw the signal. so yeah, it may be you're picking up the weak AM signal and it's being fed into the amp.

so i guess, you're solutions include ...

stop the radio signal getting into the room? maybe turn the whole room into a hollow, lead box?

failing that, remove some fillings.

Fents · Post by **Fents** » Tue Jun 28, 2005 5:22 pm

ukime wrote:depends how long it's been happening / what is really causing it.

if you've used a "bunny-ears" antenna for television, you might notice when you go and hold the antenna, the reception is better ... basically because you're being used to pick up the signal, even being close to it helps to draw the signal. so yeah, it may be you're picking up the weak AM signal and it's being fed into the amp.

so i guess, you're solutions include ...

stop the radio signal getting into the room? maybe turn the whole room into a hollow, lead box?

failing that, remove some fillings.

NEXT!

Post by **JAMESSSS** » Tue Jun 28, 2005 5:40 pm

don't touch the volume knob when you don't want to listen to the radio.

Realm Korrupt · Post by **Realm Korrupt** » Tue Jun 28, 2005 5:56 pm

Sounds like a shielding/earthing prob. Check all ya cables - try making sure all your different cables (audio,power and anything else cross att 90 degree angles instead of parallel to each other.Sometimes random signals can be picked up by a poorly sheilded cable and transferred through your setup.
Hope dis helps

quick · Post by **quick** » Tue Jun 28, 2005 6:44 pm

Hey Fents, I just called my step dad, he's a real good electrictian. He's gonna get some answers and call me back so should have an answer for you soon.

quick · Post by **quick** » Tue Jun 28, 2005 6:54 pm

Definately an earthing problem, plug the amp straight into the wall socket, not via a double adapter (earth can be broken here).
If that doesn't work, you need to check the earthing on each valve, take off the cover and make sure the green clip thingy is correctly attached, not sure what this would look like, but the earthing part of the internal workings is green, most probably with a yellow strip. One of the earthings inside it are probably not connected, so make sure they are and it will go.

juicy badness · Post by **juicy badness** » Tue Jun 28, 2005 7:42 pm

Realm Korrupt wrote:Sometimes random signals can be picked up by a poorly sheilded cable and transferred through your setup

- esp true wit unbalanced cables. keep unbalanced runs to a minimum or use a DI to convert to a balanced line which won't pick up any RF interference

Post by **JAMESSSS** » Wed Jun 29, 2005 10:43 am

reminds me of the second spin listening posts.

Fents · Post by **Fents** » Wed Jun 29, 2005 10:46 am

quick wrote:Definately an earthing problem, plug the amp straight into the wall socket, not via a double adapter (earth can be broken here).
If that doesn't work, you need to check the earthing on each valve, take off the cover and make sure the green clip thingy is correctly attached, not sure what this would look like, but the earthing part of the internal workings is green, most probably with a yellow strip. One of the earthings inside it are probably not connected, so make sure they are and it will go.

Cheers mate...thats helpfull!!!

Will sit down tonight and work through it. Cheers Ears.