Getting rid of hiss/ hum

[Timo]

[Ground Loops]

[Computer/soundcard audio noise]

[nvisibl]

Thanks a lot Timo, really helpfull

[Wandering Kid]

but all the access virus models can only accept unbalanced connections?

using balanced connections shouldnt solve anything because you will get no benefits from them. For ten's problem i imagine his unbalanced cable runs were just absolutely horrific.

could it be the global input level on the synth? try it on the access virus by going into the CTRL menu and increasing the input global parameter to maximum. notice how everything becomes hissier and the LFOs actually emit an audible high pitched squeal around 8000 hz.

on my virus b i have never really been able to get rid of the hiss or the squeal completely, even with this parameter on 0, althoguh it is greatly reduced than when it was on 127.

[AlexHall74]

Good to see you WK; long time no see on the forum.

Cheers Bro!

-Alex

[Khazul]

Does your mixer have a dedicated record bus, otherwise you will be getting summed hiss into the computer which is going to make life unpleasent.

The cables I use for connecting unbalanced outs to my mixer balanced ins seems to be very good at minimising hiss and hum.

Basically what I do is use a decent quality balanced mic cable, at the unbalanced (synth out) end, I connected cold and ground to R and hot to T, then normal TRS connection at the other end. With decent balanced inputs that can cope with asymnetric balanced signals, this yields the kind of noise immunity your get with balanced connections.

The other suggestiuon is about how you wiring you mains up.

Ensure that everything has roughly the same length path to ground (actually its the resistance to ground and therefore the voltage drop on the ground that matters). Dont connect some gear to a distribution block, which also has another distribution block pwering on gera in it. INstead use a star arrangement so all the lengths to ground are roughly the same.

Also use much thicker cable then the current of your gear would demand - this is just to ensure you have a good thick connection to ground.


If all else fails - try searching "ground loop", "mains hum" and othger suitable phrases - there loads of articale on the net about studio wiring to minimise the kind of problem you are experiencing.

If you in the USA, then you might need to provide a common ground point. 2 pin mains over there is a complete nightmare for audio installations.

[nvisibl]

Thanks for your feedback folks.
Ended up it was a groundloop issue.

What a pain in the arse it was to troubleshoot.. I got there in the end though.