Whats in your second system?

I have a secundary system in my study at home:
Harbeth P3ESR as desktop speakers
refurbished Quad 405/2 amplifier
Emotiva Control Freak plus some additional inline attenuators as volume control.
ODAC usb DAC
Computer as source for streamed music.
I have the speakers on IsoAcoustics desktop stands to get the tweeter up to ear height, and to reduce bass reinforcement from the desk surface. Even so, there still was a bit of a bass boom from the desk and I cured that with a REW equalization curve for the Equalizer Apo installed on the computer.
There is one definite upgrade in the not too far away future and that is a quieter (preferably fanless) computer. The other would perhaps be a little subwoofer. Before I do that, however, I first want to experiment with the subwoofer from my main system, to see if my study  is large enough to handle deep bass. In any case, the sound is already very good indeed for a smallish room.

I also have a very simple but nonetheless pleasant tertiary system in the bedroom:
Wharfedale Diamond 9.0 speakers
Ava Maestro 50 amplifier (with optical input)
Chromecast Audio as an optical digital source.
The amplifier is a very small and completely digital affair with an auto on/off function as its main virtue. It sits out of sight, tucked away in a wardrobe. It is turned on by a signal from the Chromecast, and is usually turned off by the TuneIn sleeptimer on the Chromecast. Unfortunately Chromecast does not have a native sleeptimer - that functionality has to come from the app for the streaming service. TuneIn has one, but Spotify e.g. does not. The amplifier is about 2x25 watt, and that is enough, but only just. I also tried it with my (insensitive) Harbeth P3ESR speakers, but it was not really powerful enough to drive those well. But I am quite happy with the more efficient Wharfedales - they are mostly used to listen to late night talk radio. But even for some casual music they are by no means offensive.

I similarly have a spare pair of Quad ELS57s, after I upgraded to the modern 2805. The 2805 is not only better, but of course has a far better remaining life expectancy. My ELS57s are still in good condition, but you can be sure you will need to have them refurbished quite soon, and that is neither easy nor cheap. Which is also why I decicided to upgrade to the 2805. I offered them to my son, but he said no: they are bound to need expensive maintenance, and they are too bulky in a student room. So once I get round to it, I will sell them, but since everybody knows that they need an expensive refurbishment second hand price is actually quite low.
My son is now working part time in a supermarket for a pair of Harbeth M30.1s, the largest speaker that he thinks will work in a student room or small apartment. In the meantime he uses my old LS3/5a’s that he is very happy with. Once he is done with those I will sell them as well. There is a crazy market demand for them.