Why is my secondhand SH-101 emitting a low buzz? Sounds like mains hum - whatever, it is not a quiet synth, and it's annoying almost to the point of unusability. I use heavy shielded output leads for all my synths , but none of the others sound bad.

Could it be something to do with the transformer? It is small (3" by 2" black in-line block) and marked "ROLAND ACF240E, number 12449565" (note for US readers - UK mains supply is 240 volts AC), and given that I got it bundled with the synth when I bought it, it may not be the correct unit.

Any guesses?

Pop Some batteries in the sh puppy and see if the hum goes away.......

Yep, try batteries and if it does go away then it is your power adaptor . Roland equipment is very particular about power supplies , look at the power supply input or on the bottom of the machine and it should say EXACTLY what power adaptor model is required . If you are using a different type it will hum or not even work . It could also damage it becuase the hum is probably meaning it is getting too much power or the polarity is switched to the wrong setting . In America the SH-101 uses the AC-120 adaptor , anything else and it will hum and do other weird things .