Sorry for being so very late to this thread. I've only just come across it.
I'm the online resource for information regarding the Koss CM Series of speakers (CM/1030, CM/1020, CM/1010, CM/530).
I've provided help to quite literally hundreds of people who have contacted me over the last two decades.
I can be reached at
junk666email@hotmail.com
If I might comment on this thread...
By now, all original Koss CM crossovers will need to be refurbished. The resistors should be replaced (they corrode from the inside out and eventually go open circuit - making it seem like a driver has failed) as well as the caps (they drift out of tolerance - resulting in output imbalances between drivers).
Ratings and values can be found (although, like the OP did, some may need to be replaced by a pair to get the right value) but tolerances on the original resistors might be impossible to find. Go with what's available. I attest that doing so will still yield like-new sound.)
I can provide schematics and other information to those who need it.
As to the discussion about the caps' 250V rating... the schematics call for 50V. No harm in going bigger, but it is overkill. Just make sure the speakers are fused as required. In addition, all of my CM/1030s (I have six pairs) have a thermistor to protect them - factory original but not shown on the schematics. The worst I've ever done is blown a fuse, or two.
And by the way, the Koss CM line are very very good speakers. And while the asking prices, like a lot of other "vintage" gear, have been going up and up, they are still a great bargain. But they will need some work. Contact me. I can help.
Jeff