K8084 on 12vdc

I bought the K8084 pre-amplifier kit for it’s volume and tone control in my car (between mp3-player and amplifier; I want no head-unit!).
The K8084-kit needs 12vac while my car, of course, offers 12vdc only.
Should I transform the power? How?
Or can I just skip the ac-power-part of the kit? Plug in the 12vdc where exactly (after the first 4 diodes? just before the LED?)

Carefull: the unit needs 2x12VAC, as it is a symmetric circuit.
This is not available in a car. There is no way to convert 1 x 12VDC into 2x12VDC (at least not at reasonable cost and effort). Possible solution: run the unit from two 9V batteries.

  • You meant 2x12VAC?
  • Further, I do not understand your solution. 2x9VDC (the batteries) to feed 2x12VAC ? Please explain.
  • Just out of curiosity: what would your solution at unreasonable cost and effort be?
  • Any alternative Velleman Kits to be used?
    Thnx.

AC or DC, does not matter, is is rectified immediately.
2x9V batteries work fine, just put them behind the rectifier diodes.
There are no kits in our range that convert 12VDC to 2 x 12DC or AC.
Furthermore, we do not carry a single supply tone and volume control.

OK thnx for your help!

Just a thought.
Couldn’t P130B18A use a transformer and use one of the inverters that Velleman sells?
Like the one in the link below.
velleman.be/be/en/product/view/?id=350493
With this could charge the MP3 player and cell phone as well.

Like I said just a thought.

Quite expensive and a guarantee for noise and interference.
Furthermore, transformers are not happy with a square wave at the input.