My son is autistic and has a fascination with numbers. LED displays are particularly troublesome, since he can spend endless minutes watching time counters. Since he also loves music like I do, I had to build a stereo system that would not become a number obsession. Here are some hints that worked for me.
Amplification: Modern receivers and integrated amplifiers almost all use digital display to indicate volume level, source selection and various equalization settings. Short of using electric tape over the display, consider going old-school. There are plenty of vintage receivers out there with analog tuners and manual controls. Think of your own youth and the lovely silver-faced receivers of the day. For reliability it's best to buy vintage gear that has been refurbished with new power supply capacitors. If you need something new, Yamaha and Marantz also sell integrated amplifiers that mimic the look of the older 1970s models. Personally, I like to use separates – I use an old Audio Research SP-7 preamplifier and a Mitsubishi DA-A10 amplifier. Both are rugged and can take the abuse of my son operating the controls.
Source: The CD player is probably the worst offender since the majority of them have displays that cannot be turned off. My own solution is to use the Pioneer DVD-V7400 – it’s an industrial DVD / CD player that has no display at all. It also has a quick loading time and is extremely rugged. Look on Ebay for used models. The old record or tape player can also be used, but some autistics have a fascination with spinning objects.
Speakers: As much as I love exotic speakers, this is a good place for something a little more rugged. Definitely use speakers with the grills on and heavy enough that it can’t easily be tipped over. Of course this is a wise decision with children of any age. In some extreme cases, a short floor-stander with metal or thick grills might be the best. I my situation, a pair of $149 KEF Q60 speakers on short stands have been good enough.
Setup: Of course you want to keep cabling out of the way of feet, so keep the speakers close to the amplifier. When my son was younger, we also kept the components up high and out of the way. Since he is older, that restriction is now gone. He now picks his own CDs, loading them up and turning the volume and selector knobs himself. He still isn't allowed to play records himself since vinyl is more fragile, but he does select them and lets me operate the turntable.