Spectral Audio builds the most advance audio eletronics available. They are remarkably reliable when used correctly. When improperly used Spectral components will be subject to damage. Spectral Audio recommends the pre-owned Spectral equipment should be purchased ONLY from an authorized Spectral dealer. A Spectral dealer will know the history of the unit and how it has been used. The dealer will have installed and maintained the componet. The vast majority of "private party" Spectral equipment on the Internet has been found to have damage due to improper use. Overture is one of Spectral's oldest and largest dealers. When you purchase pre-owned Spectral components from Overture you can buy with confidence. And we will advise you on the proper ser-up and use of these remarkable components. With that said up for auction from a recent Overture customer trade in a Spectral DMA-360 Series 1 Mono Power Amps (2) in very good condition wth box, manual and power cord.