Your #1 Source For New & Used AV Equipment. Pair of Extron ASA 304 Quad Active Audio Summing Amplifiers w/ Power Supplies on 1RU Metal Rackmount.What's in the Box? Four, independent active audio summing amplifiers in a single enclosure. Converts stereo audio to balanced or unbalanced mono audio. Stereo inputs and mono outputs on captive screw connectors. ±6 dB output gain switch. The Extron ASA 304 is a high performance Audio Summing Amplifier that converts two-channel stereo audio signals to balanced or unbalanced mono audio signals. It is ideal for summing stereo signals for use in mono multi-speaker PA systems in churches, halls, arenas, stadiums, and other environments where stereo signals would result in cancellation. This item is in the category "Musical Instruments & Gear\Pro Audio Equipment\Amplifiers". The seller is "avgearavgear" and is located in this country: US. This item can be shipped to United States, Canada, United Kingdom, Denmark, Romania, Slovakia, Bulgaria, Czech Republic, Finland, Hungary, Latvia, Lithuania, Malta, Estonia, Australia, Greece, Portugal, Cyprus, Slovenia, Japan, Sweden, South Korea, Indonesia, Taiwan, South Africa, Belgium, France, Ireland, Netherlands, Poland, Spain, Italy, Germany, Austria, Bahamas, Israel, Mexico, New Zealand, Philippines, Singapore, Switzerland, Norway, Saudi Arabia, United Arab Emirates, Qatar, Kuwait, Bahrain, Republic of Croatia, Malaysia, Antigua and Barbuda, Aruba, Belize, Dominica, Grenada, Saint Kitts-Nevis, Saint Lucia, Montserrat, Turks and Caicos Islands, Barbados, Bangladesh, Bermuda, Brunei Darussalam, Bolivia, Egypt, French Guiana, Guernsey, Gibraltar, Guadeloupe, Iceland, Jersey, Jordan, Cambodia, Cayman Islands, Liechtenstein, Sri Lanka, Luxembourg, Monaco, Macau, Martinique, Maldives, Nicaragua, Oman, Pakistan, Paraguay, Reunion.