# REW & Optical Output from my laptop



## angryht (Nov 23, 2006)

I'm sure this has been asked and answered but I could not find the answer with searches. I have a laptop which is running Windows XP. The laptop has a headphones jack that doubles as a mini-optical output. I have a usb microphone (UMM-6; calibrated from Cross Spectrum Labs). I do have a 3.5 mm jack to RCA adapter that I can plug into the headphone jack but there appears to be a short either in the cable or the jack (crackles and goes out when touched). If I just use the optical out and connect it directly into my surround receiver, will it just send the signal to one speaker? I have been told just to use the analog output (headphone jack) because there may be a delay in processing but I am concerned about a possible short in the jack or the cable. Does anyone use optical out? It seemed like there were a few using it with Macs.


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## informel (Jun 21, 2011)

I will be following this tread,as I am using a Umik-1 USB mic and would like to stay digital as much as possible


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## angryht (Nov 23, 2006)

Well, it seemed to work fine. I just had to go into the sound properties and set the balance to either left or right speaker. My test was just on a stereo system (no surround).


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## AudiocRaver (Jun 6, 2012)

There has been very little discussion of using optical output, no reason it should present any problem. Staying digital is _generally_ better, where it mimics the signal path that will ultimately be used, avoiding the analog rolloffs that we normally need calibration curves for.


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## davesspeed (Aug 8, 2013)

I recently switched from the headphone/RCA combo to digital on my Mac. I did a loopback and checked the calibration of the sound-card. At first it did not work, then I changed my output to 16 bit to match REW, and it worked great. in fact the variation was less than +/- 0.5 Db for the full sweep. I actually came on here to look for some tips for using REW with a digital signal.
Does anyone have any suggestions?


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## angryht (Nov 23, 2006)

I didn't think you could do a loop back with a digital output.


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## AudiocRaver (Jun 6, 2012)

For loopback you need dual outputs and dual inputs. With digital output, the problem is usually finding a line-level output point, like a line level out at the AVR, to loop back to the second input.


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## davesspeed (Aug 8, 2013)

My Hardon Kardon AVR 8000 has a front panel digital input and output that I plan to use to loopback to my laptop, once I get another 12' optical cable. No one around here stocks a mini to standard toslink cable so I have to order another one online. I should have ordered 2 in the first place.


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