Velodyne DD15 - worth repairing the plate amp?

CORRECTION: My Velodyne Plus subwoofers have been in my service for 12 years, not 22. Velodyne CA. Digital Drive Optimization technology may be over 20 years old beginning with the SMS-1. My apologies.

["On the other hand my current Plus 12’s and the 10 Plus are over 22 years old."  "set between +1 - +5dB between 38Hz - 15Hz for the past 22 years."] 

@kraftwerkturbo ,

It is not push pull kraft it is push push and totally relevant to this topic if you want the best performance. Take any subwoofer and play a bass heavy number at highish volume. Put your hand on the subwoofers enclosure. You will feel it vibrating, even if it is spiked to the floor. This is distortion. Ideally you should feel nothing. A sub like the Martin Logan will have 90% less vibration = less distortion. If you like distortion go with a single driver design, even s servo driven single driver design is going to have more distortion. 

mijostyn Yes, the single mass accel/decel of the driver's mass 'moves' the sub. But the push/push also causes movement (flexing the outside walls of the enclosure) in the same way. So also imperfect.

Not relevant, because this post is not about the best subwoofer design principle, but if the $400 repair of a DD-15 is a better investment and creates a better result compared to a similar budget ($800 total investement) other solutions. And how well a vintage 2008 DD-15 compares to sub $1000 new technology subs. 

I sent my plate amp in for repair (DD15) and it only worked for another year. I wasn't into paying $400 per year to keep it going, so I moved on. SVS has some nice stuff with free shipping.

try the folks in new jersey, they are velodyne repair wizards!!! and very reasonably priced as well.