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Balanced Line Input

Discussion in 'Gen 2 Prius Audio and Electronics' started by electricitylikesme, Apr 28, 2008.

  1. electricitylikesme

    electricitylikesme New Member

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    I've presently got my CarPC hooked up by a direct adaptor cable to the JBL amp. I've got a clean signal with no hum or buzz (very quiet with the computer turned on) but I've still got the typical issue that I need to turn the volume up about 20 settings higher then with the other audio components in order to get the same perceived audio levels.

    I know the reason for this is that the amp is receiving effectively half the line input level it expects since the audio from the computer is going from +ve to ground and not going negative.

    What I want to do is hook up a THAT1600 balanced line driver to send a true balanced audio signal into the JBL amp - has anyone had any experience doing this and got any insights on it? Particularly what I'm wondering is how to achieve the negative supply voltage - can it be accomplished with a simple voltage divider setup?
     
    #1 electricitylikesme, Apr 28, 2008
  2. qbee42

    qbee42 My other car is a boat

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    Use a level shifting voltage regulator to get the negative voltage. There are a lot of nice dc to dc regulators that produce complimentary outputs with very few external components. That's your best bet.

    Tom
     
    #2 qbee42, Apr 28, 2008
  3. KK6PD

    KK6PD _ . _ . / _ _ . _

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    Lets not reinvent the wheel ....
    If your output is 150/600 ohm balanced, and you want to feed a Hi-Z unbalanced input, I.E. the AUX input, all you need is a PASSIVE matching transformer. Shure, makes one that would be fine, as well as several other manufacturers. Google it!
    If you want to get really deep into this you could find a active matching package ... Those usually have a trim control to match levels. as well as the need for power.
    The XFMR should be fine!!
    If its Stereo, get 2!!!

    This is a simple fix... Email me if you want more info!!

    Good Luck de Pat KK6PD
     
    #3 KK6PD, May 13, 2008
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