The No.1 Website for Pro Audio
 Search This Thread  Search This Forum  Search Reviews  Search Gear Database  Search Gear for sale  Search Gearslutz Go Advanced
1/4 outputs to Balanced +4 patchbay - Fractal Axe FX III
Old 1 week ago
  #1
Gear Maniac
 
arsmusic's Avatar
1/4 outputs to Balanced +4 patchbay - Fractal Axe FX III

This is sort of a strange one and I am not sure what these outputs really are. I have a

https://www.fractalaudio.com/downloa...ers-Manual.pdf

Go to page 16 of the manual for the outputs. I want to wire this to my balanced patchbay. Stereo outputs 1 and 2 are xlr. Outputs 3 and 4 are called humbuster 1/4. I have contacted the manufacturer and now I am even more confused.


ME:

Are they unbalanced -10db output? I need them to be balanced +4 output.





Fractal:

Sorry, I don't have that info. I'll see if I can get it for you. Outs 3 and 4 are designed as unity gain outs, meaning that with the knob all the way up, whatever voltage you input to them, they pass to the output. That said, they have independent level controls which allow you to boost them to extremely high or low signal levels.

Then they have this thing called:
HUMBUSTER™ CABLES

On page 6 of that manual above.

To me that looks like they just connect sleeve to ring. Which would cause my patchbay to not have a normal ground anymore right?

How would I connect outputs 3 and 4 to my +4 balanced patchbay the correct way?


Maybe something like this?


Using this part
Neutrik NTE1 1:1 Audio Adapter Transformer for NMxxx Modules 848864015828 | eBay
Old 1 week ago
  #2
Lives for gear
 
Richard Crowley's Avatar
 

I have an extremely strong suspicion that those 1/4 inch outputs are TRS "Impedance-Balanced".
That means that the Tip is actively driven from the output circuit.
And the Ring is connected through a resistor to ground.
That resistor is the same impedance as the active (Tip) output impedance.
That provides the benefit of a "psuedo-balanced" output at the cost of a 2-cent resistor.

You can determine this for yourself by simply measuring the resistance between Ring and Sleeve (ground).
If it has zero ohms, then the Ring is connected directly to Sleeve/ground.
If it has some fixed, low-ish resistance, then it is probably "impedance balanced"
If it has some other weird (or varying) resistance, then it is probably actively balanced (but that seems unlikely).

Even if the Ring is hard-wired to Sleeve/ground, that does NOT mean that will "cause my patchbay to not have a normal ground anymore".
It only means that those two outputs are unbalanced at the patchbay. That has no implications for the other inputs and outputs on the patchbay.

If it ain't broke, don't try to "fix" it.
I would NOT put a transformer in there unless you actually have a problem and there is no other effective solution.
Old 1 week ago
  #3
Gear Maniac
 
arsmusic's Avatar
Quote:
Originally Posted by Richard Crowley View Post
I have an extremely strong suspicion that those 1/4 inch outputs are TRS "Impedance-Balanced".

Thanks for the info. The unit in arriving in the mail in a few days from now. I will test the resistance when I get it.

BTW my patchbay has a common ground.

If the Ring is hard-wired to Sleeve/ground should I have these channels on the patchbay not common ground and just let the ground pass through the patch bay cables? Or keep them common ground like the rest of the channels?
Old 1 week ago
  #4
Lives for gear
 
Richard Crowley's Avatar
 

Just treat those channels exactly like you would any proper balanced TRS or XLR signal. NO difference at the patchbay end.
Old 1 week ago
  #5
Gear Head
 
Sixer's Avatar
 

From the Fractal WIKI page.

Humbuster - Axe-Fx II Wiki


Sixer
Old 3 days ago
  #6
Gear Maniac
 
arsmusic's Avatar
Quote:
Originally Posted by Richard Crowley View Post
I have an extremely strong suspicion that those 1/4 inch outputs are TRS "Impedance-Balanced".
That means that the Tip is actively driven from the output circuit.
And the Ring is connected through a resistor to ground.
That resistor is the same impedance as the active (Tip) output impedance.
That provides the benefit of a "psuedo-balanced" output at the cost of a 2-cent resistor.

You can determine this for yourself by simply measuring the resistance between Ring and Sleeve (ground).
If it has zero ohms, then the Ring is connected directly to Sleeve/ground.
If it has some fixed, low-ish resistance, then it is probably "impedance balanced"
If it has some other weird (or varying) resistance, then it is probably actively balanced (but that seems unlikely).

Even if the Ring is hard-wired to Sleeve/ground, that does NOT mean that will "cause my patchbay to not have a normal ground anymore".
It only means that those two outputs are unbalanced at the patchbay. That has no implications for the other inputs and outputs on the patchbay.

If it ain't broke, don't try to "fix" it.
I would NOT put a transformer in there unless you actually have a problem and there is no other effective solution.

So, I finally got around to measuring the resistance of outputs 3 and 4. They has around 170 ohms of resistance. So, I take that is "impedance balanced." Should I wire it with trs jacks? Basically just treat it as any other trs or xlr piece of gear.


Edit:

I see that I should use trs jacks on the AxeFX unit side. So, never mind the question.
Post Reply

Welcome to the Gearslutz Pro Audio Community!

Registration benefits include:
  • The ability to reply to and create new discussions
  • Access to members-only giveaways & competitions
  • Interact with VIP industry experts in our guest Q&As
  • Access to members-only sub forum discussions
  • Access to members-only Chat Room
  • Get INSTANT ACCESS to the world's best private pro audio Classifieds for only USD $20/year
  • Promote your eBay auctions and Reverb.com listings for free
  • Remove this message!
You need an account to post a reply. Create a username and password below and an account will be created and your post entered.


 
 
Slide to join now Processing…
Thread Tools
Search this Thread
Search this Thread:

Advanced Search
Similar Threads
Thread
Thread Starter / Forum
Replies
MistyLake / So many guitars, so little time
0
tom682 / So many guitars, so little time
53
Daniel_H / So many guitars, so little time
31
Rusty_OHara / Electronic Music Instruments and Electronic Music Production
5

Forum Jump
Forum Jump