AP6.0 NOTE: This listing is for a REPAIR SERVICE where you MUST send in your broken amp for a flat rate repair!!! You are NOT buying an amplifier module! Please read carefully: Have a non-working Mackie SA1521 or SR1521Z power amplifier module? Why pay $600 or more for a new one??? Why send it to an inexperienced repair facility??? We will repair most SA1521, SR1521Z, and SWA1801 modules for a flat rate of $219 plus $25 return freight in the continental US. Most repairs are 5 to 7 business days plus shipping transit time. We've repaired over 200 of these and saved customers a ton of money! We use original parts in our repairs, not "generic aftermarket sort-of" parts. Once repairs are completed, the amp is fully tested under load. **This listing is for a REPAIR SERVICE for your broken plate amp module. It is NOT for a module for sale** Warranty on repairs is 90 days parts/ labor. We also have American-made aftermarket (better!) replacement woofers for the SRM-450's and SA1521/SR1521Z's We're Pro Digital Inc., specialists in pro audio repair services. Please message us or call our customer service line for more info on how and where to send us your broken amp. Our number can be viewed in the "ask seller a question" link. .