Thank you for viewing. This was a treasured item, but I've decided to sell it since I haven't been using it lately. Based on my testing, it seems to be working fine without any crackling. However, as it's an old product, there is some wear and tear, scratches, and marks. The manufacturer specifies a 10V adapter, but it will also work with a standard DC 9V adapter for effects pedals (though the sound will change quite a bit, so using a 9.6V adapter for effects pedals is recommended). Instant purchase is welcome. This listing is for the effects pedal unit only. I will ship it on the same day of purchase if possible, or at the latest, the next day. Thank you.