Last Update 28/09/2026
I bought this because there is no room for a full sized machine anywhere in my home. Well, strictly speaking, I cannot get permission for one.
I found a Youtube video that made the Legends Pinball Micro look like something I could find a place for.
It is a great bit of kit. I have bought a couple of extra tables to add to the 50 that came with it. I have added the coinopsx games to it and connected my Steam Deck using Visual Pinball. It works really well. At some stage I will add more detail and pictures here.
For now, I want to focus on the one problem I have found with it. A constant noise, not quite a hum, more of a rattle and buzz that comes from the speakers only when the on board pinball tables are running. This noise is not present when playing from the Steam Deck or using the Coinopsx stuff. It is not present when looking through the menus or at any other stage. Only when an on board pinball table is running. The noise is constant no matter what the volume is set at. So if you turn the volume up loud enough, the buzz/hum/noise is drowned out by the game sound.
I looked around on the internet and discovered that this is a common problem and found what looked like a solution at Raymii.org here
I ordered the parts required to put the Ground Loop Isolator together:
The Pinball Micro uses JST SM4 plugs to join the speakers in the top section to the lower section, so this is a good place to insert the isolator as the assembly instructions with the Pinball specifically state taking the back off the top section and plugging the wires together. The plan is to disconect this junction and simply insert the Ground Loop Isolator having replaced the RCA sockets with JST SM4 plugs.
The wires to the original plugs, the wires on the new JST SM4 plugs and the wires on the Ground Loop Isolator are all different colours. To avoid confusion whilst soldering, I drew a plan:
This is what it looks like with the speaker JST SM4 plug disconnected. Note the helpful marks on the speakers denoting left and Right
Below is the GLI with the two male RCA sockets cut off to expose the wires that will go to the speakers. Red for left and yellow for right
The new JST SM4 plugs with black (left +), green (left -), red (right +)and blue (right -) wires
Soldered and insulated
Complete and ready to be fitted
Sound before inserting the Ground Loop Isolator. The noise you hear is exactly like that no matter what the volume of the pinball machine is set to.
Sound after inserting the Ground Loop Isolator
Well, that has fixed it nicely. However, the audio is now so quiet that even on full volume the audio is not very loud at all. I am guessing it's the cheap GLI that is causing this. I have contacted the person who made the original article to try to find out which GLI they used. Failing that, I may just have to fork out for a better one. More later.