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crochambeau
08-21-2009, 06:14 PM
Hello,

I'm preparing to rebuild a pair of N1200S out of a pair of Sunn PA speakers, as one of the HF driver no longer works in one. It's a D130F/LF175 8 ohm two way, and I've noticed mention of a 16 ohm system as well...

I have a schematic for the N1200, sans S designator, that calls out 16.5uf, 12uf and 13.5uf for C1,2 and 3 respectively. Attached is a gutshot of the bad x-over, those caps are going away. I'm having trouble deciphering the value from that code, and am not inclined to trust actual measurement of a 40 year old paper cap.

http://i7.photobucket.com/albums/y273/earthman606/MISC%20electron/n1200s.jpg

What are the nominal values of C1,2 and 3 for an 8 ohm system? What I have printed in the N1200 schematic?

Dead stock or improved x-over point suggestions both appreciated.

crochambeau
08-30-2009, 10:05 AM
Maybe it'll help if I rephrase the question?

I've got a failed N1200s crossover working with an 8 ohm compression driver load, the caps as plucked from failed unit read 14, 41 and 43uf on my meter. I have a printed schematic (for N1200, minus "s") that indicates cap values of 12, 13.5 and 16.5uf, but have also read about a 16 ohm compression driver variant and am unclear as to what load the printed schematic is designed to drive.

This is because I cannot decipher, from the schematic alone, if the 13.5 and 12uf are electrically in parallel or are swapped out at different switch positions.

Were these mine, I'd just buy the caps and take the hit if they turned out to be wrong values, but I'm doing this as a favor to a friend and don't want to spend his money uselessly.

Any insight (if available) greatly appreciated.

4313B
08-30-2009, 10:28 AM
I did a search on N1200S and my moniker and here's what showed up:

#9 (http://audioheritage.org/vbulletin/showpost.php?p=209881&postcount=9)

#11 (http://audioheritage.org/vbulletin/showpost.php?p=209888&postcount=11)

crochambeau
08-31-2009, 07:10 AM
Excellent, so the caps in the S have gone waaaaaaaaay out. I thank you for your time!

The switching arrangement is much more understandable in the N1200.pdf you posted than the N1200.pdf I harvested from jblproservice...

Thanks again! :bouncy: