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[Joseph D. Macry]

So I'm installing mic jacks in a Gymnasium floor pocket. Cursing the electrician because he ran my conduits to the wrong side of the gym, meaning over 400 foot run to get to rack in closet that is otherwise maybe 60 feet away. Then comes the change order saying to add a stereo 3.5mm jack. No room in the floor pocket for passive DI or even RDL transformer. No one wants to hear why I think 400-odd feet of unbalanced run is a bad idea. My boss says Just put it in, if it fails it's their fault.
SO: stereo 3.5mm jack connected to about 460-odd feet of mic cable (unbalanced, shielded stereo) going outside and around the gym, into the Rane mixer in the rack across the hallway.
I was astounded when sound from the iPod sounded loud and clear. No buzz, plenty of level. Same result with audio from a laptop PC.

Said the designer: "Told ya."   

[Steve M Smith]

If you are running from the headphone outputs, then you will have a fairly high level so the signal to noise level will be low.


Steve.

[Josh Millward]

SO: stereo 3.5mm jack connected to about 460-odd feet of mic cable (unbalanced, shielded stereo) going outside and around the gym, into the Rane mixer in the rack across the hallway.

Yes, this can be done.

However, I would highly recommend running one cable for the left channel and one cable for the right channel.

Then, I would further recommend wiring them as described in diagram 2.1 on page 2 of this document:
Jensen AN-003 INTERCONNECTION OF BALANCED AND UNBALANCED EQUIPMENT by Bill Whitlock

Please note that in this document he is talking about connecting just a single RCA/Phono type of connector, so only one channel. Your 3.5mm mini-plug has two channels. So, connect things accordingly.

[Joseph D. Macry]

Yes, this can be done.

However, I would highly recommend running one cable for the left channel and one cable for the right channel.

Then, I would further recommend wiring them as described in diagram 2.1 on page 2 of this document:
Jensen AN-003 INTERCONNECTION OF BALANCED AND UNBALANCED EQUIPMENT by Bill Whitlock

Please note that in this document he is talking about connecting just a single RCA/Phono type of connector, so only one channel. Your 3.5mm mini-plug has two channels. So, connect things accordingly.

Thank you for the advice, but the installation is already complete.

[Josh Millward]

Thank you for the advice, but the installation is already complete.

Yes, I understand that.

However I was trying to share with you two things:

1. It is not that unusual for this kind of thing to work just fine without a hitch. (Of course, it would be much nicer if the electrician would have run the conduit to a more intelligent location so you didn't have to run cables that far.) The other thing working in your favor here is the low impedance of the headphone output on these devices.

2. The next time you need to do this sort of thing, please consider running a line for each channel and connecting it as shown in that documentation. Be sure to include the cost of the extra wire in the change order.

Have fun and good luck!

[ProSoundWeb Community]