^^ Yeah, that's why I linked the manual but those range specs are not in there. Niles made / makes some very good stuff. The unit is UL Listed and adjustable over a wide current sensing range. I checked one more reliable source for you - the Crutchfield site and they use to sale this. There's a posting there "
Note: According to Niles Audio, the power consumption on the component plugged into this unit must be at least 30 watts to trigger the 12 volt output." ->
https://www.crutchfield.com/S-pqehCVTRkHx/p_190CS12V/Niles-CS12V.html
Now within the 5 comments at Crutchfield, there was this from a purchaser in 4/2017: "This product works as advertised. When setting it up, the Niles CS12V is "nulled" to the standby current of the control component, so that even components that don't draw much current when switched on can trigger the CS12V. I have it slaved to a
Schiit Audio SAGA mini-preamp that draws less than 25 watts when on, and the CS12V triggers a Benchmark AHB2 power amp on and off without any problems. The CS12V also has a delay function, although I have it defeated. The Niles CS12V is a convenient way to upgrade components that do not have the 12V trigger function built-in."
Looks like YMMV.
That's as close as I could come for a "no-build" option... 15W may be difficult. So maybe digging into the many adjustable "Smart Power Strips" and finding one there + a 12VDC wall-wart/transformer with 3.5MM male plug is your best option. Maybe that other thread will find something too. It's gotta be a common ask in this space.
LOL one more thing... you might consider getting putting a pair or so of small wattage bulbs parallel with the switching DAC device. For example, like a couple of 8W "old fashioned night lights!" You could add some "warm glow" to the areas behind the DAC and AMPS while raising the min threshold for the Niles CS12V trigger. Your DAC turning on would be just enough to activate the Niles trigger. Yeah they would have to stay on all the time so not quite ideal but another thought. Just keep a few bulbs on hand. I recall they are the old "Holiday Tree" bulbs that may be getting harder to find.
You could probably do the same thing with some LED rope lighting if you get enough current draw... That would last longer than the incandescents and still deliver a warm glow. If this is near a TV, then the "MediaLights" might be an win/win there if the power is in the range you need.
Look at it this way too, for ~$30USD, assuming you are in the US, you could try the one from that
first ebay seller with 100% positive and 8000+ reviews. If it does not not work like you want, especially with the above, then re-ebay it! (Keep the shipping box)!
There's a point in your life where searching is costing more than doing/trying a possible solution at a reasonable cost. The one thing you cannot buy more of is time.
IDK of any other 100% OTS solutions which won't require some custom building ATM. Please post your final solution. Stay safe, stay alive!