Sound output has been confirmed. Channel switching is also available, making it convenient. There is some minor crackling, but currently, I don't feel any major crackling. Notes: Please understand that this is a used item and is being sold as-is before bidding. Please refrain from bidding if you are looking for a perfect condition item or are overly concerned about details. We are not responsible for damage caused by shipping. Please arrange for maintenance if necessary. We may cancel bids from those with negative feedback or if we determine that the transaction cannot be carried out smoothly. No claims and no returns accepted.