What's the deal with Model Five crossovers?

[JKent]

I've worked on a lot of Model Five crossovers and most had point-to-point wiring but a few used printed circuit boards. I always "assumed" the PCBs came later but looking at serial numbers of the ones I've worked on it looks like PCBs were in the middle (??).

I don't have serial numbers for all the ones I worked on because in some cases people just sent me the crossovers but the earliest SN I have is 1103 and the latest one I have is 21148. Those both had point-to-point as did most of the others in between. But 06845 and 12470 had PCBs. SN 10436 falls between those and it's point-to-point.

This may be one of those unsolvable mysteries but does anyone have a clue?

Also, were th production dates 1968 - 1972?

thanks

Kent

[dxho]

Can't help you on xos, but production (or at least availability) dates
for the Five went through 1977, according to buyer's guides of the time.
Same for the Six, Nine, Seventeen, Thirty One, and Thirty Two.

[JKent]

Thanks for the info. Every list of KLH products available has inevitable inaccuracies. One said '68-'72, which seemed short. The KLH Model History pinned the the beginning of the KLH section shows 1958 for the Five which I thought to be way off but then remembered they did have an earlier, different Model Five. Weird. I should have checked your list at http://www.aphenos.net/electronics/speakers/klh/all_klh.htm which is generally more accurate and does show '68 '77 for the Five.

[KJ244]

Hi Kent - I can add my data points from a pair of Model 5’s I recently refurbished. SN 43332 and 43338 had 1971 date code capacitors and the pcb version x-overs. Kevin

[JKent]

On 3/14/2021 at 8:12 PM, KJ244 said:

I recently refurbished. SN 43332 and 43338 had 1971 date code capacitors and the pcb version x-overs.

Interesting. 43338 vs the newest one I'd worked on: 21148. So 22,190 between the two. Makes sense yours had pcb but I still don't get the inconsistency among the lower SNs. Probably never will 🤨