I've just added a couple of nice upgrades to my Cube, so thought I would share them in case others might find the info useful.
Firstly, as you know the Cube has no built-in audio I/O. I don't have the original USB speakers that shipped with the Cube, but from most accounts they are style over substance. For a while I have been using a cheap Chinese mini USB 'sound card' but the quality was terrible. So I picked up this Phonic Firefly 302 FireWire audio interface from eBay for under £20. It is powered straight from the FireWire port, it sounds great with headphones, and can also be plugged into speakers.

Secondly, my internal DVD-ROM has never worked properly since owning the Cube, discs always got stuck, a common problem. I noticed recently though that the optical drive no longer shows up in System Profiler at all, which leads to my question - has anyone else experienced this with a Cube? Even when discs were getting stuck it would still show up as a device and read discs etc, but now it's as if it's not even there.
Anyway I didn't want to attempt replacing or repairing the internal DVD-ROM as they are prone to failure anyway, so I picked up this neat little External one which is also powered solely by FireWire so no external PSU required. It works as a boot drive which will be handy if I ever have to do an OS install from scratch again. The model is a Dell SEM-Q10E, this was also from eBay and under £10.

And finally, although I usually like to stick to 'period' apps and wallpapers etc, I think the Big Sur background looks great so thought I'd post a photo of my setup
I was not a fan of the black keyboard and mouse that came with the Cube, I think this mini iMac keyboard and white mouse suit it much better.

Hopefully this will help anyone looking for similar peripherals, being limited to USB 1.1 rules out most modern external optical drives and audio interfaces so FireWire was really the only way to go.
Firstly, as you know the Cube has no built-in audio I/O. I don't have the original USB speakers that shipped with the Cube, but from most accounts they are style over substance. For a while I have been using a cheap Chinese mini USB 'sound card' but the quality was terrible. So I picked up this Phonic Firefly 302 FireWire audio interface from eBay for under £20. It is powered straight from the FireWire port, it sounds great with headphones, and can also be plugged into speakers.

Secondly, my internal DVD-ROM has never worked properly since owning the Cube, discs always got stuck, a common problem. I noticed recently though that the optical drive no longer shows up in System Profiler at all, which leads to my question - has anyone else experienced this with a Cube? Even when discs were getting stuck it would still show up as a device and read discs etc, but now it's as if it's not even there.
Anyway I didn't want to attempt replacing or repairing the internal DVD-ROM as they are prone to failure anyway, so I picked up this neat little External one which is also powered solely by FireWire so no external PSU required. It works as a boot drive which will be handy if I ever have to do an OS install from scratch again. The model is a Dell SEM-Q10E, this was also from eBay and under £10.

And finally, although I usually like to stick to 'period' apps and wallpapers etc, I think the Big Sur background looks great so thought I'd post a photo of my setup

Hopefully this will help anyone looking for similar peripherals, being limited to USB 1.1 rules out most modern external optical drives and audio interfaces so FireWire was really the only way to go.