# Sequential Circuits Pro One
“READ THIS!!! Up for sale is a Sequential Circuits Pro One monophonic synthesizer. Everything works except for the arpeggiator and there is a humming noise. All knobs and switches are intact.
Cosmetically the synth is in good if not great shape. A few scratches as pictured. The wooden panels are in good shape. Fourth to the last key slightly hangs lower. All keys work and it stays in tune. As for as the humming noise, sequential explains this as a ground loop. I think it might be the power cable. The hum will disappear when using a ground lift, but Sequential does not advise using a ground lift (in other words it’s a no no). The hum noise does lower at times and the keyboard is still usuable. Apart from the hum, it sounds good and puts out some great bass sounds. Could use a service. I was going to send it out, but have decided to invest in something newer. I have owned this synth for a little over a month and got it on ebay. I am not selling it for what I paid for it. My loss, your gain. The synth is sold as is.” Link