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?
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
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
