Random newbie questions - please help

[twatts]

OK, I've been taping and playing for a few months and I'm definitely still Newbian...

And now I have a few more questions, some concerning the UA5, others concerning cables and patching...  I've looked through the FAQs, and have found lots, but haven't found answers to my specific queries:

I sometimes tape out of the SBD at my local bar and run the RCA outs into my UA5 into my Nomad 3 thru optical out.  I used to run the SBD RCA line-out into the back of the UA5 where the "volume" can be controlled.  This however controls both right and left equally...  So then I got some RCA>1/4" mono plug adapters so I can now run the SBD into the front of the UA5 into the XLR-1/4" inputs.  These have "sensitivity" knobs and can be adjusted right and left...  Here is my question:  IS THIS A PROBLEM???  What exactly is the difference between running into the back and running into the front?  Does doing this run the SBD signal thru the pre-amps?  

And this brings me to my next question:

This same SBD has a loose connection on the right RCA out, so I've thought about using the XLR outs.  I went and bought some XLR>RCA cables (2 - right and left) for SBD XLR out > RCA > 1/4" adapter plug > front of UA5 inputs.  

Is this going to be a problem???

I have no idea what balanced and unbalanced XLR is and what the SBD is outputing.  I'm concerned about hot signals and attentuators and transformers and such and such...

And on a side note, what exactly is the difference between a SPDIF digital coax cable and a regular RCA cable.  Can I use an RCA in place of a Digi-Coax???  I haev a digi-coax (RS $10), but I'm curious...  What does 110ohms vs. 75 ohms mean???

Thanks for any and all help.  Flame away too for my ignorance!  Its all good!

Terry
db.etree.org/twatts

[sexymexi]

k i think i might be able to answer a question or two.  

i don't think it makes a difference running the ua5 with the RCA's and mic inputs in front.  i'm taking you have just a digi mod ua5.  so there wouldn't be any signal processing or warming preamplification if you have the warm mod ua5.  

secondly, balenced xlr from my experience in studios, i was told that the basic difference in balenced and unbalenced cables are that the internal wires are exactly the same length, and from my use of non balenced cabled i have got some radio stations on some recording cause of it.  its kinda like an antenna, with power going through it, and it receiving a radio signal, and the signal and the difference in length of wires is the same, or close, and you get radio reception.  in theory it would be possible if you could easily adjust the difference in length of the wires you could tune in radio stations. kind crazy. but interesting.  

other might have other things to say about that, i hope it helps. +t man.  

matt

[super-phat-al]

thats interesting about the balanced and unbalanced cables.  Ill never forget when it was 3 am and i left my stereo on and all of a sudden private radio chatter is being broadcast.  It was insane.

[dklein]

I sometimes tape out of the SBD at my local bar and run the RCA outs into my UA5 into my Nomad 3 thru optical out.  I used to run the SBD RCA line-out into the back of the UA5 where the "volume" can be controlled.  This however controls both right and left equally...  So then I got some RCA>1/4" mono plug adapters so I can now run the SBD into the front of the UA5 into the XLR-1/4" inputs.  These have "sensitivity" knobs and can be adjusted right and left...  Here is my question:  IS THIS A PROBLEM???  What exactly is the difference between running into the back and running into the front?  Does doing this run the SBD signal thru the pre-amps?  

Not a problem.  Front inputs have more gain if you need it (the pre-amp), more connection options (1/4", XLR, balanced, unbalanced) and phantom power.  Rear is just straight line level input.

And this brings me to my next question:


This same SBD has a loose connection on the right RCA out, so I've thought about using the XLR outs.  I went and bought some XLR>RCA cables (2 - right and left) for SBD XLR out > RCA > 1/4" adapter plug > front of UA5 inputs.  

Is this going to be a problem???

Not a problem.  Would be better to just go SBD XLR>UA-5 XLR with a standard mic cable (XLR female on one end, male on the other).  That way you'd be running a balanced connection instead of unbalancing it before sending it down the cable.

I have no idea what balanced and unbalanced XLR is and what the SBD is outputing.  I'm concerned about hot signals and attentuators and transformers and such and such...

Google it if you want technical info.  It's a way of preventing external noise from entering into your signal through the cable.  Requires balanced equipment on both ends of the cable (your UA-5 front panel).

You may find the signal hotter off the XLRs.  Soundguy can usually control the output level so if he's working with you it shouldn't be a problem.  I have had to turn the front input gain all the way down to 0 in a situation or two but the recording still came out great.

Don't get into attenuators or transformers if you don't need to.  And most transformers are there to step it up, not down.

And on a side note, what exactly is the difference between a SPDIF digital coax cable and a regular RCA cable.  Can I use an RCA in place of a Digi-Coax???  I haev a digi-coax (RS $10), but I'm curious...  What does 110ohms vs. 75 ohms mean???

Impedance - kind of the internal resistance of the cable.  You can often get away with anything if the distance is short.  75 ohms is also used for video (usually a yellow cable).  No point in spending money here.

[twatts]

YOU ARE THE MAN!!!

Thanks DKLein!!!  I thought about using mic cables from the SBD XLR to the front of my UA5. and will do that instead...  But getting the XLR>RCA adapter let's me go to the back too.  

Thanks for all the help, I have yet to test the XLR out over there, but we'll see!

Let me send you some SHNs:  db.etree.org/twatts

Terry