ADS 910 Capacitor Polar or Non Polar?

[Mr. Bessette]

Hello all!
Forgive the question if it shows a lack of working knowledge of crossover networks (I don't have a lot of working knowledge of crossover networks, I specialize in amplification) but I've always understood crossovers to utilize bi-polar electrolytic caps when they do use them. The ADS 910 crossovers sometimes seem to have a non-polar cap (crimps on both sides visible in photos) but the one on my bench now has a cap that looks very much like a non-polar cap. This seems to be original as per some other photos I've seen. The cap in question is the 90uf @ 100v cap in the woofer network.
The cap shows many signs of being polarized (doesn't hold a charge from a 1v source one direction but will hold it the other, crimp on only one end, looks like the Mallory caps found in vintage power supplies in DC application, appears to have one lead attached to the case) but I am looking to change it due to the value having drifted to 140uf and not trusting an electrolytic this old and I'm not sure if I should go with a higher quality cap such as an F&T 100uf @ 100V polarized cap or going with a nichicon 100uf @ 100v bi-polar cap. The schematic seems to indicate a polarized cap by symbol but I'm believing this to be a mistake as they show the polarized cap symbol for all caps including film variety, meaning -| )- vs -| |-

Thanks for any light someone could shed on this for me.

 

[Freddymac2]

The higher uf caps are bigger and more expensive, and are used on the lower frequency drivers, where many deem it is not as important. I used Axion and Solen PP caps on all of my replacements, C1 was a polar electrolitic originally. The difference in the purity of sound was LARGE across the band, and the bass was tight, fast and finely detailed, like a different speaker. I think partsconnection has them on sale now. Not connected in any way.

 

[Finjima]

It just so happens that I just got in a pair pf 100uf ECAP50-Plain Mundorf electrolytic caps for replacing on my 1230's. bipolars. And welcome to AK, there is a few members here with the 910's who have or may have replaced those caps so they will know for sure what the deal is with those caps your working with. The cross over is different than on my 1230.

 

[Mr. Bessette]

It just so happens that I just got in a pair pf 100uf ECAP50-Plain Mundorf electrolytic caps for replacing on my 1230's. bipolars. And welcome to AK, there is a few members here with the 910's who have or may have replaced those caps so they will know for sure what the deal is with those caps your working with. The cross over is different than on my 1230.

Thank you! I've lurked for a while and finally have joined up, this has been a great resource of technical information. I look forward to sharing any information I come up with for parts subs, repair techniques, etc.

 

[GD70]

Thank you! I've lurked for a while and finally have joined up, this has been a great resource of technical information. I look forward to sharing any information I come up with for parts subs, repair techniques, etc.

I have not replaced any caps in my crossovers. I'll be watching to see what caps you use and the results. My 910's sound superb and have held off doing any crossover work. The only thing I did was send the mids and tweeters to Richard So for rebuilding. They sounded very good, and after the rebuild sounded a bit better with more depth and details in the highs. The main reason though was for preservation. Richard use to work at ADS and bought all the parts inventory when ADS closed its doors. I figured there's only so many original parts left and one day they will run out.
Let's see some pics when you get a chance and do yours have their badges and the factory stands?
Cheers, Glenn

 

[Mr. Bessette]

These belong to a friend who has only brought me the crossovers, but he does indeed have the stands! I will report the results as relayed to me from the my friend who owns them.

I have not replaced any caps in my crossovers. I'll be watching to see what caps you use and the results. My 910's sound superb and have held off doing any crossover work. The only thing I did was send the mids and tweeters to Richard So for rebuilding. They sounded very good, and after the rebuild sounded a bit better with more depth and details in the highs. The main reason though was for preservation. Richard use to work at ADS and bought all the parts inventory when ADS closed its doors. I figured there's only so many original parts left and one day they will run out.
Let's see some pics when you get a chance and do yours have their badges and the factory stands?
Cheers, Glenn

long

 

[Mr. Bessette]

It just so happens that I just got in a pair pf 100uf ECAP50-Plain Mundorf electrolytic caps for replacing on my 1230's. bipolars. And welcome to AK, there is a few members here with the 910's who have or may have replaced those caps so they will know for sure what the deal is with those caps your working with. The cross over is different than on my 1230.

Would there be no worry of over voltage on a 50v cap in this position? I ran a 100w bench amp through the crossover at 200hz and measured up to 25vac across where this cap goes with the volume only as loud as I felt comfortable with late at night.

 

[GD70]

Would there be no worry of over voltage on a 50v cap in this position? I ran a 100w bench amp through the crossover at 200hz and measured up to 25vac across where this cap goes with the volume only as loud as I felt comfortable with late at night.

Matching the UF rating is what is important. Higher voltage rating is fine.

 

[Mr. Bessette]

Matching the UF rating is what is important. Higher voltage rating is fine.

50v is less than the original which is 100v, so the 50v cap is 50v under the original value. That cap does look nice but I'm wondering what voltage rating is required for the application and if that cap is suitable headroom for this crossover.

 

[GD70]

50v is less than the original which is 100v, so the 50v cap is 50v under the original value. That cap does look nice but I'm wondering what voltage rating is required for the application and if that cap is suitable headroom for this crossover.

You want the 100v then. I wouldn't go any lower. I see where I misunderstood your comment.

 

[soundmotor]

Hello all!
Forgive the question if it shows a lack of working knowledge of crossover networks (I don't have a lot of working knowledge of crossover networks, I specialize in amplification) but I've always understood crossovers to utilize bi-polar electrolytic caps when they do use them. The ADS 910 crossovers sometimes seem to have a non-polar cap (crimps on both sides visible in photos) but the one on my bench now has a cap that looks very much like a non-polar cap. This seems to be original as per some other photos I've seen. The cap in question is the 90uf @ 100v cap in the woofer network.
The cap shows many signs of being polarized (doesn't hold a charge from a 1v source one direction but will hold it the other, crimp on only one end, looks like the Mallory caps found in vintage power supplies in DC application, appears to have one lead attached to the case) but I am looking to change it due to the value having drifted to 140uf and not trusting an electrolytic this old and I'm not sure if I should go with a higher quality cap such as an F&T 100uf @ 100V polarized cap or going with a nichicon 100uf @ 100v bi-polar cap. The schematic seems to indicate a polarized cap by symbol but I'm believing this to be a mistake as they show the polarized cap symbol for all caps including film variety, meaning -| )- vs -| |-

Thanks for any light someone could shed on this for me.

Loudspeakers w/ passive crossovers use non-polar/uni-polar capacitors, they run on AC. As far as the one that might be polarize in yours, it is marked w/ a "+"?

 

[Finjima]

I know about the 50v rating on the cap and size wise it is larger than the original. so I'm giving it the experimenter go and see how she sounds, I injured my ankle recently and I would have put them in today but wanted to rest instead. This cap was recommended to me by kevin at http://www.humblehomemadehifi.com/Cap.html who I been having a dialog on and off recently over caps and crossovers. he is familiar with the Brann's over there in the EU. Audio note also makes a 100uf cap that looks nice but I thought giving this a go first. I also learned a few other interesting things I'll go over once I get into the cross over when I pull them out

 

[Finjima]

Got the caps in but... when ohming each speaker I found I have one blown woofer, that is going with another one that's rubbing the VC so looks like I'll be for sure sending in ma woofers to richardSo. On the plus side the caps sound great! don't judge the rating on the cap too harshly, I'm not in a frat house cranking my speakers all year. it really is excellent sounding on the bass, the old cap ohmed out at 5 ohms!!! the other 4.7ish. the new ones .2 which is good. which is the point of this post, replace those electrolytic caps. how I did if for mine since it was a axial type was I did this

Here you see I mounted the cap on back of the board, following the trace I just drilled new holes in the best place for the one lead

a closer look at the new hole next to the 2 old holes, see how they were placed on the edge of the trace

I cleaned each new hole with flux before I soldered in the new cap. I was going to go into something I'm working on but with the blown woofer I'll hold off for now, (I'm mapping the crossover and measuring each component) for future project when I refurbish the speaker
even with one blown woofer the speaker sounds great so I'll baby it till its time to send em off

 

[Finjima]

quick follow up for our ADS guys my woofer is OK! I talked with a buddy of mine who I got the speaker from and he talked about retesting the woofer by taking it out and testing at the terminals so I did and it tested good, so I just hooked em back up and it works great now, Must have needed terminal reseating or something, weird. after a day running in the bass has gone to another level, sounds like a whole new speaker, You can feel the bass now, I don't need to use loudness at low volumes now