Help with crossover!
- Thread starter fermaleb
- Start date
-
- Tags
- crossover electro voice
They are all non-polar caps. 
DEFTECHY
Well-Known Member
Those blue ones are definitely mylar film caps, TI, "tecate" is the brand, nothing special about them, just a standard mylar film cap. Crites speakers sells mylar caps of equal or better quality for a couple dollars each and the polypropylene caps are of better quality & still just a few dollars to maybe $5ea for the bigger values. Worth a call or email to them for a quote on the caps you need and international shipping wont be very expensive at all for light weight caps.
The other black ones look like film caps too but will let others confirm that, or send a pic to Crites to see what they think? The one on the left of your pic looks like some of the layers peeled back, that looks like a metallized polypropylene film cap. The black with red ends Im not sure of, but doesnt look like normal aluminum canister electrolytic caps.
For a basic recap you really cant go wrong upgrading to decent quality film caps, you can stick with mylar for all the caps or upgrade to polypropylene. Again, its worth contacting Crites to see what they suggest & get prices if you cant find a reputable seller more local with decent quality caps.
Best of luck on the recap!
StimpyWan
Addicted Member
The black/red caps are electrolytic. They were also sold under the Callins brand, which Acoustic Research used in many different models. They're junk now, as I've always found that they test way out of spec.
The black SCR caps may be film, as SCR also manufactures Solen and Axon film caps. But, they look pretty rough. I'd replace those too. Plus, the blue mylar. Do a clean sweep...!
Strange that both speakers exhibit the same problem. What is the model number for the speakers? Have you tried to find a crossover schematic online? Are there mid and hi frequency controls?
The two small film caps appear to be part of the high frequency circuit. I'd leave those alone for now.
Looking at the circuit board, I'm guessing that the mid frequency driver is likely controlled by the horizontal 6.8 uF cap as a first order high pass, followed in series by the coil marked "967" and the vertical 6.8 cap and 1.5R resistor as a first order low pass (coil) with a zobel (cap and resistor in parallel with the driver). Any of those 4 components could be bad. Definitely replace the two 6.8 caps. Easy to measure the 1.5R in circuit since you removed the adjacent cap. Measure the resistance of the coil marked "967". It should read very low, less than 10 ohms probably. If it reads very high or open, then it may have an open winding and needs to be replaced.
Hope that's not too confusing.
Looking at the circuit board, I'm guessing that the mid frequency driver is likely controlled by the horizontal 6.8 uF cap as a first order high pass, followed in series by the coil marked "967" and the vertical 6.8 cap and 1.5R resistor as a first order low pass (coil) with a zobel (cap and resistor in parallel with the driver). Any of those 4 components could be bad. Definitely replace the two 6.8 caps. Easy to measure the 1.5R in circuit since you removed the adjacent cap. Measure the resistance of the coil marked "967". It should read very low, less than 10 ohms probably. If it reads very high or open, then it may have an open winding and needs to be replaced.
Hope that's not too confusing.
I've had that happen with a pair of Pioneer speakers I got from a friend. Thought the tweeters were fried but it was the caps on both. Tweeters were fine.
Electro Voice Saphir. No more data, I haven't found much online.
the surroundings, the suspensions, disarm by themselves. They will be 30-40 years old.
No, there are no mid and high frequency controls.
I have measured the other components and they seem to be fine.
white resistor= 1.6
Gray resistor=4.9
coils: 0.4 (small ones) 0.8 (big ones)
kind regards!
Well, long story short, this has been a "cross course" for me. Thank you so much!
I really didn't know anything about it (it's the first thing I'm going to do)
I learned the following:
-capacitors must NOT be polarized.
-capacitors can be connected in parallel to reach a given value (preferably with similar values)
-Voltage must be equal or higher. I also found this on the web: Voltage Rating: 160Vdc = 100 Vac
-all components were identified
Possible capacitors to use, within reason:
1) non-polarized electrolytic caps (traditional aluminum pot) Too cheap / not very good.
Film caps: (mylar or polypropylene)
2) MKT - metallized polyester film (Mylar)
3) MKP - metallized polypropylene (these seem to be preferred)
Regarding the supplier, I can get capacitors from Audyn and Jantzen, among others, shipped to me from Germany (at reasonable costs). SCR from Distrilec in Switzerland.
Audyn seems fine, maybe I'll use Jantzen in the future for my dear JBLs.
I really don't think I'll stick with these boxes. I bought them at auction for $23 and have yet to re-foam the woofers that were rotten (many years old)
I think that in order not to spend a lot, a good middle ground for everything would be Mylar, although I don't find much difference in price with MKP.
I saw there are Audyn Q2 (160V) which are also MKP and at 27 uf I guess this would be a good replacement for the 26 uf cap
Now I have to ask for the spare parts, take a walk with the family and, when I return, wait for the good weather to pass, ask the sky for rain (something that happens here all the time) and go into the cave to work for fun.
Surely my OCD won't let me wait that long...
Thank you very much everyone for the help!!!!!!!!!!!!!
Sincerely,
Martin
PS: sorry for my bad English, the online translator helped me...
I really didn't know anything about it (it's the first thing I'm going to do)
I learned the following:
-capacitors must NOT be polarized.
-capacitors can be connected in parallel to reach a given value (preferably with similar values)
-Voltage must be equal or higher. I also found this on the web: Voltage Rating: 160Vdc = 100 Vac
-all components were identified
Possible capacitors to use, within reason:
1) non-polarized electrolytic caps (traditional aluminum pot) Too cheap / not very good.
Film caps: (mylar or polypropylene)
2) MKT - metallized polyester film (Mylar)
3) MKP - metallized polypropylene (these seem to be preferred)
Regarding the supplier, I can get capacitors from Audyn and Jantzen, among others, shipped to me from Germany (at reasonable costs). SCR from Distrilec in Switzerland.
Audyn seems fine, maybe I'll use Jantzen in the future for my dear JBLs.
I really don't think I'll stick with these boxes. I bought them at auction for $23 and have yet to re-foam the woofers that were rotten (many years old)
I think that in order not to spend a lot, a good middle ground for everything would be Mylar, although I don't find much difference in price with MKP.
I saw there are Audyn Q2 (160V) which are also MKP and at 27 uf I guess this would be a good replacement for the 26 uf cap
Now I have to ask for the spare parts, take a walk with the family and, when I return, wait for the good weather to pass, ask the sky for rain (something that happens here all the time) and go into the cave to work for fun.
Surely my OCD won't let me wait that long...
Thank you very much everyone for the help!!!!!!!!!!!!!
Sincerely,
Martin
PS: sorry for my bad English, the online translator helped me...
Last edited:
Seems like you're on the right path to bringing these back to life. Enjoy the learning experience.
This is my best guess to what that crossover looks like. Hard to be sure from the one picture of the board, but it seems fairly conventional. Hope this helps your learning.
This is my best guess to what that crossover looks like. Hard to be sure from the one picture of the board, but it seems fairly conventional. Hope this helps your learning.
@fermaleb i was like you a few months ago. It’s overwhelming at first. So rewarding to both enjoy the improvements and know that you did it yourself.
I’ll pass on one tip…go to local auto stereo shops to find provisional crossover caps. I’m going after low $ speakers and hoping to rejuvenate potential keepers. A keeper ultimately gets worthy caps. But at present I have a couple pairs with clipped in provisional caps, to be revisited later but at least I know all drivers are good and I heard some semblance of potential.
Fwiw, speaker addiction starts like this. Hop on!
I’ll pass on one tip…go to local auto stereo shops to find provisional crossover caps. I’m going after low $ speakers and hoping to rejuvenate potential keepers. A keeper ultimately gets worthy caps. But at present I have a couple pairs with clipped in provisional caps, to be revisited later but at least I know all drivers are good and I heard some semblance of potential.
Fwiw, speaker addiction starts like this. Hop on!