Dayton Audio HPSA 1000-R subwoofer amps. Parts Express #300-810 in excellent condition with original boxes. No scratches, dings, or cosmetic blemishes. I used these for a couple of Bill Fitzmaurice designed subs that I built, but my new sub project will be using different amps. $250 each. Two available. Shipping to USA only via U.S. Mail.