Thanks everyone for your help. I've been reading user comments about Dayton Audio's products and hum does come up frequently for some of their amps. I didn't see much about hum for the SPA250 and SPA230. I'm starting to like the idea of a stand alone amp, such as the SPA230, rather than a plate amp. I wouldn't have to deal with the cutout and maybe it would last longer than a plate amp too.
Anyone have suggestions for a stand alone subwoofer amp in the 200-300 watt range? Dayton's SPA230 looks OK but I cannot find the low end frequency response for Dayton's amps and PartsExpress can't tell me either.
PE also has a 300w BASH plate amp but I doubt the cutout size will work. PE also cannot tell me if this is a now defunct O Audio product or a product made by a company called Bash. I couldn't find a "Bash" company online.
MK Sound cannot provide any additional info to what's been provided on Audioholics. They no longer have the parts and technical information for the V-100 and other older M&K subs.
I'll be home this weekend and I'll checkout the driver, measure the cutout, etc. on the V-100. I'm also looking at just replacing the entire sub with an Outlaw, SVSound, or HSU sub. Even though I really liked the V-100, maybe it's time to just let it go.