Leslie wrote:

Great workmanship John! It's fun to do, right?

You bet, Leslie. This is very rewarding work.  To think that these speakers might have ended up in a dump and now listening and looking at them all fixed up, it is a really nice feeling.

Sonavor, I'm finally  getting around to recapping my crossovers. I opened one up last night to check the capacitor values, and oddly enough, this crossover is variation on the other 3 versions you posted.  It has a total of 10 caps, including the little one in the Protection circuit.  

Just thought I'd share - these are MS150s.  

I'll post impressions of sound once I get them redone in the coming weeks.  

Your crossover board looks like it is the same as my original MS-150 speaker (the type with the finished rosewood on the back of the speaker), with the difference being you have a capacitor at the top-center of your board (using the orientation of your picture).  What is that capacitor value?  Is it a 22uF, 100V bipolar type?

yep, that's a 22 uf (all are 100V non polarized) & yes, same finished rosewood on the back side

Looking at the picture (earlier in this thread) of my original MS150 crossover, I am wondering if my crossovers are missing that capacitor. It wasn't in the recap kit I got from Martin so it must have been the first change on those speakers.  I believe the MS150 speakers with rosewood on the backs were first generation. Those were followed my MS150's that did not have rosewood on the back.  Then came the MS150.2 model. Those had a different cross-over, different mid-range and different padding inside. 

I currently have my original MS150 and the MS150.2 speakers side by side and connected to the Beosystem 8000.  I am not able to tell a difference in the sound by my ears (not scientific of course).  They both sound good to me.  I still need to restore the third set of MS150's.  I have another complete Beosystem 8000 (including the SC80 cabinet) that I am going to work on later this year. That will give me another set to compare with. 

It's really hard to tell, I would think it wasn't missing it, maybe just a variation of the theme?  

Would you happen to know the value of that tiny little capacitor in the protection circuit?  Unfortunately, I missed it and the speakers are back together now.  In your opinion, how critical is it to replace if I'm recapping the rest? Not even sure what it does, any insight on that would be great, thanks much!

The protection circuit has two electrolytic caps.  The maroon colored, radial capacitor is a 100uF, 63v polarized cap.  The smaller, gold colored, axial capacitor is a 1uF, 63v polarized cap.

All of my MS150 series speakers I acquired in non-working state. Since they are quite a job to open up, I recapped the crossover boards when I had the speakers apart to work on the woofer surrounds. So I can't really speak to how critical it is to recapping them other than it was recommended and I preferred to not go back in to the speakers again.  I own quite a lot of speakers and most of them have no protection circuit. I have yet to ever blow out a pair of speakers...maybe I don't listen to music loud enough :)

If your speakers sound okay and the protection circuit isn't cutting the sound off when it shouldn't you are probably fine leaving them as they are.

Thank you so much!  

Hello all,

I am a new member to this forum and a new Beo owner! I have acquired a pair of MS 150's that had been refoamed and generally put back to good working order. However, it wasn't long before one of the phase link drivers decided to part company with the voicecoil (straightforward enough fix thanks to this forum). But I was assisted in the dismantling of the cabinet and did not take personal note of the wiring configuration.

Could someone please point me to photos or diagrams of the wiring, specifically of the upper (smaller) bass driver/woofer?

Thanks for the help in advance.

Joshua

Hi Joshua, welcome to the forum. I'm glad the post helped out on your project. Can you post some pictures of the area you are having a problem with?  What version of the MS150's do you have?  It sounds like you are asking where the white and gray wires from the crossover attach to the smaller woofer, is that right?

-sonavor