Different systems playing same music simultaneously

I have four different systems located in different rooms.
Is there a way to make them play the same music like a multi-room system?
Could I send the signal from one source to all the systems at the same time?
Each system has its own amplifier and speakers.
Is bluetooth an option? Can I use a transmitter and several receivers?
Does anyone have this kind of setup?
00eb89d7 2c78 4fdf ad0b d96d4df77747migueca
I think you can do this with a number of streamers. I can do it with the now end of life Logitech Squeezebox, so I imagine it is a common feature.

You can do this through Roon.
Bluesound is probably what you want. 
A set of Nodes- and they don't have to be the latest edition, will give you what you want as a very competitive price.
It is what I am using as I write...

Depend on setup.
If all analog signals means running lots of long runs of cables and a multi out box, can be done but it's work.
Networking as Audiotroy states is better option.
But all depends what you have in your systems.
Guys we sell the Blue Sound products which are fantastic, however, only Roon gives you the ability to talk to many different devices,  so through Roon you can talk to Sonos, Google Chromecasts, Naim Muso, Naim  Uniti products, Auralic, and many, many others.

Blue Sound's Node is a very good $550 streamer, however, a high end Roon server coupled to a good Dac will sound even better.

Dave and Troy
Audio Doctor NJ
I am using a Dayton Audio wave link 2.4 GHz wireless transmitter/receiver to send signals from my music room to a second system in my kitchen.  Bought from Parts Express.  Cost about $60.00.  Works great but there are certain limitations.  You'll need an output from the preamp and assuming you are sending an output to your amp you'll need a second pre output.  Tape out could work or maybe headphone out.  Transmitter and receiver work best with line of sight between the two.  Call Parts Express with your questions.  

This is pretty easy with Chromecast groups. The Creation 5 control point also does it with diverse renderers, but Chromecast is much more reliable. 
I like that this was brought up . I’m sure many of us have a,b and c systems around the house .be nice to have set up when your busy around home going from space to space. Make leaving the sweet spot more tolerable. I’ve been meaning to pick ip a second one . Likely the new version so the wife can play apple stuff when I’m not around. Then and only then . 
I currently do this throughout my house across 4 different systems. One is my main home theater system, the other a vintage console stereo, the next a Fisher 400, and finally a set of computer speakers. I do it 2 different ways. The first is I have Google Chromecast Audio devices on each of them. They are no longer made, but, you can get them on eBay. They work great and use analog 3.5mm stereo jacks that you just put a 3.5-RCA splitter on. They’re wireless so zero cabling. To sync them up you simple create a “group” that includes all the devices you want synced up and name that group. Mine is called “the house”. The you choose whichever music streaming service you want as your default and simple say, “Hey Google, play Miles Davis in The House”. Then it streams in sync to each system wirelessly. In a separate input I do the exact same thing with Apple Airport Express’. They are also no longer made, but, again eBay. I do the same thing with those for my downloaded music on my computer. I just select all the devices from my MacBook in the audio drop down menu when Apple Music app is launched. Hope that helps a little.
An addendum to my post. You’ll need a Google Home or a Google Home Mini as a control unit to initiate the stream. Spotify, Google Music, Pandora, etc
Thank you for the suggestions. I see some interesting solutions...
What I have right now is a bunch of old style amplifiers. Some solid state, some tubes. No streamers, no modern receivers/amplifiers with network connectivity.
So I'd like to try something like a dongle that I can connect to each of the amplifiers to receive the signal (coming from a computer or a phone). I think there are already some receiver devices that can be synchronized in order to receive the same signal at the same time. Am I right?

Meanwhile I did a short research and it seems the most effective devices for what I need (at a reduced price) are the Chromecast Audio, the Dayton Audio Wave Link and similar products.

@migueca yes, that’s the systems I have. My Fisher 400 and console are vintage tube receivers. My Arcam is a modern receiver. The Google Chromecast Audio units are individual “dongle” devices. They connect on their own to your WiFi through minimal setup. So your receiver or amps do NOT need to have any sort of connectivity. They simply need an analog RCA input.
I have Sonos speakers in several rooms and three complete systems, Media room, shop and garage. You put a small Sonos "Connect" on each system and everything talks to everything via your wireless network. You run the whole thing with an app on your phone. Very cool to have the whole house going at once. Great way to get your wife to commit suicide:)
One imagines nobody has heard of the problems associated with multiple speaker rooms or, if they have, assume just because the speakers/systems are in separate rooms they don’t affect each other. Even if they don’t act acoustically. It’s similar to the concept that cell phones in the room degrade the sound. Is that too advanced?
No, not at all too advanced. Knowing that cell phones in the room destroys the sound is, um, like day 1... helllllooooo
Real crying shame Google ceased production of the Chromecast Audio puck.
Great little device.
I have two of them on two different systems and control them from either Google Home or bubble UPnP on my droid phone.
No issues at all.
They see Qobuz, tidal, Spotify and my nas on the PC.
Not bad for $40 a pop of Fleabay.