LPS for Optical Network Terminal (ONT)

We have fiber coming into our home with a Nokia ONT/Router combo and I want to add a LPS for streaming. The ONT presently has a wall wart providing  12V, 3A to power it.  Can I  just splice in a standard   US NEMA   plug to the existing wire for connection to a LPS, or, do I need to purchase some specific wire  (which already has an ONT connector) to go  between a LPS and the ONT ? 

I know this sounds extremely simple but I just want to make sure the rewiring doesn't screw things up due to my overlooking something obvious.  I can be very good at overlooking the obvious   😥

Thanks for any insight,



Is the output of ONT fiber optic or copper? Is the SMPS on the same circuit as your system? I could be wrong, but if the SMPS is not in the same outlet or even circuit as your audio components, replacing it with LPS is most likely not going to make a difference. Also, if the output is fiber optic, the light carries the digital signal and as such it is not susceptible to EMI and RFI - there’s no noise in that transmission line. Once you convert fiber optic back to copper, that’s where I’d start cleaning things up. 

If your goal is to power your router with a LPS, then you need to purchase a LPS that delivers 3A of current at 12V DC.  The LPS you purchase should come with a DC power cable to connect the LPS device to your router, and it should also come with an AC plug/cord to connect the LPS device to the duplex in your wall.  Not sure why you would want to splice in a NEMA plug.  Others can address the potential benefits, or not, of using a LPS for this purpose.  FWIW, all my network items including modem, router, and peripherals (such as converters and switches) are powered using LPSs.

@audphile1 @mitch2

The output of the ONT is an internet wire (COAX), not optical. I am trying to post a link to an image of the power cord going into the ONT but I am having trouble. Here is a try;


The ONT has a power input that looks like the bottom image in this link. I didn’t know if it is possible to buy a cord with that type of connection for the ONT, and, the correct connection for a LPS, or, if all LPS come with wires with that type of connection at the other end for an ONT. I’ve never had a separate LPS before.

Thanks for your patience with me.




I thought I saw that connection when I googled your device.

From the picture, it appears that the A connection is the +12 VDC and the B connection is the - or return.  Looking at the connector raises the question whether this device has an internal battery back-up?  

Regardless, all the external LPSs I have used transform AC to DC and output two wires to a barrel connector, XLR connector, or two-pin connector.  I have put together cables for this a few times and I use a volt meter to determine which of the wires, and which part of the connector, is positive and which is negative.  On barrel connectors the inside pin is typically positive and the outside of the barrel is usually negative.  In this situation I would probably ask, "what problem are you trying to solve?"  If it were me, I would leave it alone and use the PS provided, running off of a circuit different from what powers your audio system.  Others here may have a better solution. 

Thank you Mitch. I am trying to reduce any noise that may be coming through the electrical service grid in town as I am in the process of demoing some higher end DACs.

I guess you can see where my confusion is coming from. I appreciate your help though


Get an ifi Power adapter for any networking gear you are concerned might be putting noise into your AC line. No kludging necessary

I would only worry about this if your network gear is physically or electrically near your audio gear though.  My front-end modem and router are excessively protected against surges and have a UPS to keep my networking running even when the power is out, but I reserve the ifi adapters for anything actually in my HT rack, which has about 40' of Ethernet between them.

@brskie ,

I am interested in your project, too. I have Fios with an ONT that, if possible, benefit from a LPS, but never considered it until now.

I was going to add a LPS to the router, but your method makes more sense.