• We would like to remind our members that this is a privately owned, run and supported forum. You are here at the invitation and discretion of the owners. As such, rules and standards of conduct will be applied that help keep this forum functioning as the owners desire. These include, but are not limited to, removing content and even access to the forum.

    Please give yourself a refresher on the forum rules you agreed to follow when you signed up.

WICKED WIKI 7: Balanced connections, HumBuster

yek

Moderator
Moderator
There are balanced and unbalanced inputs/outputs on the Axe-Fx II. When to use which? Here are the basics.

A BALANCED audio connection consists of an balanced output, connected to a balanced input, through a balanced cable. The cable can have either XLR ("microphone cable") or 1/4" jack plugs. A balanced 1/4" jack plug is the same as a stereo plug (but doesn't make the signal through the balanced cable a stereo signal). Balanced cables have 3 wires! More information in Wikipedia.

So what are the advantages of balanced signals?
  • Improved reduction of external noise and interference.
  • The ground lift switch at the rear can be used to fight hum caused by a ground loop.
As stated above, for this to work all 3 balanced components must be present: output, cable, input. Using balanced cabling to connect to an amplifier without balanced inputs serves no purpose. Commonly, devices such as mixers, effects processors and stereo power amplifiers have balanced inputs.

Outputs:
The Output 1 XLR plugs are balanced. Use balanced cables to connect the XLR outputs to a mixer, studio monitors etc.
The Output 1/4" jack plugs are not balanced.

Inputs:
All rear inputs on the Axe-Fx II are balanced. These inputs sense whether the incoming signal is balanced or not.
The front input is not balanced.

Is it a sin not to use balanced connections? No, most guitar players probably never make use of it. But given the fact that the Axe-Fx provides you with the opportunity to use this technology without disadvantages, why not make use of it?

The 1/4" jack outputs on the Axe-Fx II are not balanced. Fractal provides its own technology to fight ground loop hum through these outputs: HUMBUSTER. (Now is a good time to whistle the Ghostbusters theme...)

HumBuster senses and subtracts the ground noise of connected equipment using a simple stereo-to-mono (TRS-to-TS) 1/4" jack cable. Ready-made cables are available from Best-Tronics. The "stereo" end goes into an output on the Axe-Fx II, the mono end goes into the other device. You need two for stereo L/R connections.

HumBuster connections can be used in Four-Cable-Connection rigs, or when connecting the Axe-Fx II to a head or power amp, or when connecting to other devices. There's no signal loss or degradation. It reduces ground loop hum only, not pickup hum or other noise.

Wiki: Humbuster cables
Wiki: Balanced/Unbalanced


To get a list of all Wicked Wiki threads: type "Wicked Wiki" in the Search box.
 
Last edited:

reclavea

Power User
Are the 1/4” humbuster jacks themselves on the AxeII and AxeIII balanced wiring?

I’m extending the jacks to a rack panel and need to know if I should run a TRS plug from the humbuster jack to a balanced stereo 1/4” jack?

Or should it be just a normal TS plug to a mono 1/4” jack?
 

yek

Moderator
Moderator
If you want to extend the connection at the Axe-Fx end, you should establish a TRS male-to-female connection.

Correction: thinking about it more, this is not needed. It can be a TRS male to TS female connection inside, connected as shown below. This allows you to use a simple TS-TS cable to connect the external device.

 

reclavea

Power User
If you want to extend the connection at the Axe-Fx end, you should establish a TRS male-to-female connection.

Correction: thinking about it more, this is not needed. It can be a TRS male to TS female connection inside, connected as shown below. This allows you to use a simple TS-TS cable to connect the amp.

Thanks Yek!
 

reclavea

Power User
Thanks Yek!
Hmmmm so .......the jack is basically wired “balanced”....rendering it still ok to use with full TS cables but with the added benefit option of using “humbuster” wired cables that help treat potential “ground loop” problems.
 

chris

Legend!
Hmmmm so .......the jack is basically wired “balanced”....rendering it still ok to use with full TS cables but with the added benefit option of using “humbuster” wired cables that help treat potential “ground loop” problems.
The send itself is Unbalanced, as labeled, so yes, normal TS or Humbuster cables are fine.
 

reclavea

Power User
The send itself is Unbalanced, as labeled, so yes, normal TS or Humbuster cables are fine.
I stand corrected ....they are “unbalanced”.

I completed wiring up and connecting the extension from those jacks to the rack panel.

1/4” balanced TRS to a TRS Female panel jack.
 
Top Bottom