• The move to the new server is done. There are some software and database maintenance updates in process. This has us passing the hat around to help out. We appreciate any donations. Seriously, even a dollar helps. The payment page may be found here - https://www.audiokarma.org/support.html

Cable question - line level + shielded

El Cavano

El Cavano

Active Member
I'm running a length of cable from the output of my Audiobox recording interface to my Sony receiver (str-5055). It's a length of 15-20'. I used speaker wire, in a pinch.

Turns out there is distortion when I play the signal through my amp, though not when I listen directly on the recording interface via headphones.

I'm guessing that my cables are not adequate, and that I need shielding.

What sort of cable would work the best in this situation? Does the + connector go to the core wire and the - connector go to the ground/shield wire? I'll need a 1/4 inch connector on the box and RCA's on the reciever. Will my 1/4 connector need to be TRS?

Thanks for your help!
 
Register to hide this ad
TRS is to connect 3 wires, in balanced lines. To connect 2 connectors, you can use a TS plug. An extra shielding (TRS) won't hurt.

I've followed this guide with success recently:
http://www.rane.com/note110.html

Scroll down to find your connectors and the suggested wiring. I think #10, #12 and #16 apply to your setup.
 
Thinking I might use a four wire (2 twisted pair) shielded cable - terminated on each end with a 1/4 TRS plug. At the "input" end where it goes into my receiver I will have a 1/4 inch to RCA adapter plug for each 1/4 plug.

Audiobox V22 1/4 inch Main out (R) -> 1/4 Male TRS plug -> one twisted pair (maybe plus shield) -> 1/4 Male TRS plug -> 1/4 inch to RCA adapter -> Receiver input
Audiobox V22 1/4 inch Main out (L) -> 1/4 Male TRS plug -> the other twisted pair (maybe plus shield) -> 1/4 Male TRS plug -> 1/4 inch to RCA adapter -> Receiver input

Guessing I'll need to run a test wire from the shield to ground at either the Audiobox end or the receiver end. Hmmmm.

Or I could do it with two separate cables. I kind of like only running one through my ceiling tiles though.

Just spit ballin' here.
 
watch out, the shield is connected only to one end, the "output" of the 1st device.

I think those TRS to RCA "adaptors" will connect the shield (Shield on the TRS) to the RCA outer ring, tip to tip, but 1 conductor could be disconnected (the "ring", I don't know how that adaptor works, it's probably "mono", designed for 2 conductors)...

I'd use the #12 as it is: 1/4" TRS at one end, RCA at the other end. Less adaptors, less problems.

Also, I prefer to run the channels in separate cables. I don't know if you could have some crosstalk interference between signals (probably not)

Go ahead with the test wire, before the definitive setup!
 
Seems like it's getting harder to get inexpensive balanced cable wire. Any suggestions for a decent price on cables? I'm hoping to stay in the .30 per foot range.
 
Provided appearance is not a prime factor, I've used the basic shielded wire found at home improvement stores and had no noise problems.
 
More thoughts, typically using unshielded cable may result in hum, buzz, or more generically, noise ingress. However, if it is distortion then I think the type of cable probably is not the main problem.

Actual distortion would more likely be caused from overloading the input on the receiver or something like that.
 
Last edited:
Perhaps a configuration setting on my Audiobox interface. hmmm...Lots of traffic on this one on-line. Perhaps I'll try turning off the network connection and/or wireless service. I've also heard a powered usb hub can help. Both cheap fixes.

Glad I didn't order cable just yet.
 
Not much of an issue of cable quality except most insulation for the cost/ft. We have guys here running digital cable for short run and some long runs for input. If experiencing local 'junk' (not sure of what trying to achieve) I've got 12ft of optical to a denon Av/ amp w/no issues. If using close proximity cables on inputs like hand helds etc i'm not there. Like running fm on wireless amp powered speakers. Sometime moving the 'gadgets' around helps.

bink
 
I was doing some work on my system over the weekend and I took a closer look at my "problem" cables. Noticed something very funny.

The output from my recording box is a 1/4 inch output. I used a TR connector - connecting one wire to the single conductor and one wire to the shielding. Um, that just looks dumb now that I'm investigating. Sheesh - not my best work for sure.

No wonder they sound like crap!

Planning to resolve this hokey cabling in the very near future, as discussed in some detail above.

Thanks!
 
I'm assuming "Active Balanced" is what you'll find in that sort of gear.

http://www.presonus.com/community/Learn/balanced-unbalanced

The proper way to connect this type of active-balanced output to an unbalanced input is to simply leave pin 3 disconnected.

Signal voltage appears between pins 1 and 2, which is just what our unbalanced input wants.

This is another instance where you’ll probably need to modify or custom-build a cable if the output is on an XLR connector.
 
You must log in or register to reply here.
Back
Top Bottom