I sent my World 600 amp back to Stewart on May 6th for warranty repair (it gets plenty of air including a rack fan but was cycling on and off with I suppose, thermal problems). Anyway, I called today July, 3rd and the amp is still "in line" waiting to be repaired.. She said that they were really backed up... no ****. I got zero apology and they said they would "try" to get it out late next week, which then will make it over two months away for repair. Now what does that tell us? Are their amps are so unreliable that they get a lot of them back and can't repair them fast enough? The tone in receptionist' voice sort of told me that this terrible turn around time problem is nothing new. At any rate, I am very disappointed with their seemingly lack of concern or lack of a simple apology for the inconvenience of not having my power amp. This does not instill any confidence in me for Stewart Power Amps. Let this experience be a warning to you Stewart amp owners in case you have problems now or in the future. Be sure you have a spare amp and don't hold your breath waiting for your repair.