Specs for C-1 & M-500

I have a Carver C-1 preamp and a M-500 power amp and not having any luck finding distortion specs on them. Anybody have them handy? Thanks

Can't find the C-1 but the C-11 which is it's twin black face version has THD .04% or less below 3 Vrms...the 500 is listed as unmeasurable.

Thanks, don't think I've ever run into a power amp with unmeasurable distortion before. Thats interesting. I think i saw somewhere that the slew rate was really high too.
I was considering trading them in towards a pair of Hafler 9505's but maybe I should re-evaluate.