This is being sold by AUDIO DESIGN AND SERVICE INC. We are a PRO AUDIO repair center. We have been in the business for over 15 years. It is tested. BUY WITH CONFIDENCE All sales are final. NEED Repair. We’re selling our testing stock. Due to the nature of replacement parts and their tested status there are no returns on these sales. All sales are final. Unit outputs make popping sounds on power up. After it's stable. USA shipping preferred, email us if you would like international shipping. Please check out our excellent feedback rating and view our other items up for auction. We have many auctions of studio equipment. If you have further questions about this item, don’t hesitate to email us.