Powering My Logitech Surround Speakers With Pure Dc.





Most surround sound speakers for pc systems use a transformer and rectifiers to convert 120 volt AC to the DC that the electronics need.

Since my pc is dc powered from my Solar battery bank, I wanted to get rid of the transformer in my speakers to reduce idle power consumption and waste heat from it.

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Step 1: Open the Bass Speaker.

Yes there is alot of screws but it's necessary to remove all in order to get the guts out.

Step 2: Remove the Bass Speaker and Transformer.

The bass speaker can be easily disconnected. The culprit transformer can be cut out and discarded.

Step 3: Remove the Amplifier Board.

This is the board that takes input from the pc sound card and outputs to the speakers.

Step 4: Adding a Noise Suppressor.

The amplifier board needs 12 volt Dc to operate. I intend to take 12 volt from my atx psu to power it. Atx psus are noisy so a noise suppressor is needed for clean sound output. I used the same AC power chord to get dc into the amplifier board.

The rectifiers were removed and stored for future projects.

Step 5: Reassemble and Enjoy!

Put everything except that nasty transformer back in the reverse order of removal. The mounting holes for the transformer needs to be plugged else an annoying wheezing sound will come from the subwoofer. I used silicone.

Now my speakers are powered direct from my Pc for higher efficiency and less waste heat.

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    9 Discussions


    9 months ago

    Many thanks... I did it. it is amazing.

    I have connected with Bluetooth device.

    2 replies
    FLR Handcraft

    1 year ago

    What wires You use to power the amplifier board? the blue ones that were comming to transformer?

    1 reply

    2 years ago

    Nice project. So you tried them with solar or car battery?

    I used to run Creative 2.1 from car batteries (Sometimes carried in car if Car deck was bad). The adapter was external which made the job very easy.

    1 reply

    Reply 2 years ago

    Actually I power them from the 12volt PSU rail in my PC which consequently is solar powered.


    3 years ago

    you do realize that speaakers always run on some form of AC.

    1 reply

    Reply 2 years ago

    Half correct. Music is always AC at speaker level, but amp needs DC. Its the job of AMP to convert this into melodios AC. Feeding Mains AC in speakers will simply destroy them.