New To Balanced Cables!

[DJBobby11 0]

Hi there,

I was using a cheap ground loop isolator between mixtrack pro and my mixer l&r inputs but it reduced sound quality so I have just bought a behringer hd400 its a ground loop isolator but also converts signal to balanced so I'm thinking of upgrading to balanced cables & am a little unsure. . . The bits I need to connect are:

 

Mixtrack pro controller - behringer hd400 - behringer 802 mixer - w audio da1000 amp

 

The behringer hd400 thing outputs a balanced signal so what leads from that into the mixer & what leads from mixer to amp? I normally use l&r mono jacks & this whole balanced/unbalanced ting has done my head in lol do I still need L&R jacks but the TRS ones?

 

Any ideas & thanks in advance

 

 

[McCardle 1]

You can't run true balanced throughout this system, for a start the audio outputs from the mixtrack pro and the stereo inputs on the mixer both appear to use phono / rca jacks. All that you can do is use Phono to Mono Jack leads for each channel when connecting between the Mixtrack and the HD400, and then the same again to output from the HD400 into the Stereo line input of the mixer.

 

Using a mono jack instead of a stereo (TRS) will run as unbalanced.

[DJBobby11 0]

Thanks for the reply, The mixtrack has phono outputs (unbalanced I understand) but on the mixer where i normally plug it in to (left&right jack) says it takes balanced or unbalanced. The hd400 says it converts to balanced so I was thinking of going from phono out on the mixtrack into twin mono on the hd400 then supposedly after getting rid of the buzzing it makes a balanced output

 

Then its just the leads from hd400 output(2 jack) into mixer(normally use 2 mono jack)

and outputs on mixer to amp(again normally use 2 mono jack)

 

Should I just use the normal twin mono jack cables?

[superstardeejay 0]

The mixer can't convert the unbalanced outputs from the mixtrack into balanced inputs. If they originate as unbalanced, then the mixer will keep them unbalanced on its inputs.

 

The 802 only has unbalanced outputs as well so you won't be able to run balanced into the amplifier.

 

Professional equipment of course uses balanced signals throughout but the units you have mentioned are really bedroom dj or at best semi-pro.

 

Balanced signals are an electrical specification, not simply a different type of connector.

 

The Hum Destroyer will be a sort of balun, and is for eliminating mains induced hum on long cable runs eg from mixer to amp etc. It might not be successful on HF switchmode noise.

 

If you have a buzz problem then it will originate in the laptop. A decent quality ground loop isolator between the mixtrack and the mixer will work with no degradation in quality. Dont lift the earth on the laptop adapter.

Edited February 2, 2013 by superstardeejay

[Megasong 0]

Balanced leads have hot, cold and screen, Tip, Ring and Sleeve respectively on a 'stereo' jack (TRS) and Pin 2, Pin 3 and screen/shell. There is no connection between ground and either of the signal wires. This has to start with the originating equipment and be carried on as far as the balanced signal can go, through each additional piece of equipment.

 

The balanced principle works by having a pair of out of phase signals on the hot and cold which means that any picked up interference will be neutralised by having equal and opposite signals on the two conductors. It will not get rid of any noise or interference which is sent down the wires from the source.

 

As soon as you get a non balanced signal, where the ground is used for one side of the signal as in a mono jack or phono connection even if it's just at one end, you lose the benefits of the balanced signal no matter what leads you use.

 

There are ways of changing an unbalanced into a balanced signal, either using matched impedances (resistors even) at the non balanced ends of the cable in what will be the cold and the hot wires, or by using a transformer, you can sometimes find units to do this ready made. These will stop hum etc. pick up by the cable but as already mentioned will not get rig of any that is put into the cable from the source. It can also help with earth loop problems which should never occur if you are using only balanced throughout.

 

As you have already found out you can put an unbalanced signal into a balanced input just by connecting ground and cold. If you are using high impedances such as guitars that have unbalanced outputs the DI box you would use to send this signal over a greater distance to the mixer will convert this to a low impedance balanced signal, either passively or by using a small pre-amp often powered from the phantom mic supply. These can sometimes be used as a means to get a balanced signal from other equipment at a push.

 

Earth loops and HF from switch mode PSUs are the two biggest causes of interference, balanced will prevent the earth loop between two balanced pieces of equipment and allow a cleaner signal transmission but that's all it will do. As already suggested a GOOD quality hum suppressor - with choke and caps - will normally get rid in injected out of range signals such as these but in the case of the 50/60Hz (UK/US) hum they WILL degrade the signal, there are ways of removing it but it's better not to have it in the first place. Buy professional kit and the problem should never occur with a couple of exceptions.

 

PCs with inferior sound cards often let through HF SMPSU noise that intermodulates as well as making it's own presence felt, and multiple digital effects used without a Worldclock can also cause big problems.

 

I could go on but I've probably already got boring so if there's anything specific anyone wants to know please ask.