Reddit reviews Hosa PWD-402 Piggyback IEC C13 to NEMA 5-15P Power Cord, 2 Feet

You could do something like this, and just use the regular pi power plug.

https://www.amazon.com/dp/B0010EHNJG/ref=cm_sw_r_cp_awdb_t1_SBcWDbS18B19S

Get one of these. You plug it into the TV, and then plug the chromecasts wall wart into the other plug

Shipping it a little cheaper if you get it through Amazon. It is still sold by CyberGuys but hey, it's a little cheaper.

edit: This one has free shipping with Prime but the cost is a little more and it is more of a cable than adapter.

Not for DVI.

For USB, if at least one of them acts as a hub you could go from it to the other one. This won't reduce the number of cables, but will probably reduce the length of cable runs and cable clutter.

Your question made me realize that there's probably such thing as a daisy chain C13 power cable, and I found one on Amazon , (search for "C13 daisy chain" or "C13 piggyback" to see more choices).

I got the cables in yesterday and had a quick test before my house party. Results were stunning.

I plugged my bodypack transmitter into my mixer out with the XLR to Shure TA4 cable and put the receiver by my speaker. I used the IEC to NEMA piggyback cable to still use the one speaker power cable. I scanned for the best channel and got the bodypack to match just like I was doing a lapel mic setup.

At the mixer I got the wired speaker working, then I turned on the wireless speaker. I'm using EV ZLX-12P speakers so the wired speaker gain was set to unity, and I toyed around with the wireless speaker gain. Because I'm putting a line level signal in the microphone system it was really boosted. I ended up putting the gain to about 1/2 (9 o'clock position). I messed around some with the gain on the bodypack transmitter, but opted to leave it alone since I use the lapel function more often.

What ended up happening is when I turned up the main level at the mixer the wireless speaker would lag behind a bit since the gain was set lower than unity. I was also able to pan left to right to adjust the level of either speaker (I had the wired plugged into left and the wireless plugged into right). I did experiment setting the wireless gain to unity and use the pan to adjust the levels, but that didn't give me much playing room.

Overall the wireless speaker will be playing at the same volume when I start out with low volume music, but when I crank it later in the night the main speakers will be louder. This isn't a big deal for me since I want to use the wireless speaker in a dining room and it will be OK to be lower.

The distance between the transmitters was only about 15 feet and went through my kitchen wall with a microwave and oven in the way. No issues over this short distance. When I first got my lapel system I tested it in my backyard and went about 200 feet into the woods and had no issues with audio dropout. I expect similar results with the mixer as the sound source.

This weekend I'll give it a trial run by putting the wireless speaker under a table for music in another room. I also have some wedding gigs coming up later this month I can try it at a venue. The only downside is the bodypack is battery powered only. I'll have to watch the LED for it to light up red indicating the batteries are low. So far this has been the best $30 investment ever.