Strange Caps, and Help with Inductor

[ouimetnick]

Hi everyone. I did make a thread on this before, and got one reply. Well that previous thread was about the caps only. So could someone figure out the value of the inductor? It says C681K. I know I don't NEED to replace it, but when I rebuild the crossovers, I get OCD, and want to replace it if possible. The caps are going to be replaced no doubt, but I don't know their values.

 

[Copa1934]

Is this all you have? No info on the speakers they came from? If those are part numbers then someone who knows the make and model might be able to help. So, unless someone recognizes those from experience, be difficult to say with any certainty. If you find someone with WT2 or WT3 they could physically read them, though if the caps aren't new and have drifted in value you won't know the correct/rated value.

 

[ouimetnick]

Is this all you have? No info on the speakers they came from? If those are part numbers then someone who knows the make and model might be able to help. So, unless someone recognizes those from experience, be difficult to say with any certainty. If you find someone with WT2 or WT3 they could physically read them, though if the caps aren't new and have drifted in value you won't know the correct/rated value.

Sorry. They are Technics SB-2660 Speakers. They are cheap and crummy, and will be great to toss outside for halloween music. So I just want to rebuild the crossover.

 

[battradio]

Sorry. They are Technics SB-2660 Speakers. They are cheap and crummy, and will be great to toss outside for halloween music. So I just want to rebuild the crossover.

Buy a cheap LCR meter and mesure them , that the easyest way .

 

[ericj]

The caps are 3.3uf and 2.2uf. Virtually guarantee it. 50 volt not that it matters because you WILL replace them with film, right?

No clue on the inductor. 681 could mean 68mH or C681K could be a part number. Measure the bobbin and wire and count the windings and plug into a calculator, or buy/borrow an LCR to measure it.

 

[EQmeat]

Those look like pretty good inductors. Do not replace them.
Just get some Dayton polypropylene film caps. like these http://www.parts-express.com/pe/pshowdetl.cfm?PartNumber=027-420. Just get the right uF values and don't worry about the voltage rating it doesn't change the way they operate as long as they are 50 volts or higher.

 

[Copa1934]

The caps are 3.3uf and 2.2uf. Virtually guarantee it. 50 volt not that it matters because you WILL replace them with film, right?

No clue on the inductor. 681 could mean 68mH or C681K could be a part number. Measure the bobbin and wire and count the windings and plug into a calculator, or buy/borrow an LCR to measure it.

Honestly I didn't think it would be that simple. Seemed too obvious, but makes sense as I've seen different characters used to represent decimals or commas.

 

[ericj]

Honestly I didn't think it would be that simple. Seemed too obvious, but makes sense as I've seen different characters used to represent decimals or commas.

Well, the values make sense as well.

It's odd marking but for example a 2.2ohm resistor is often referred to as 2R2.

In the USA we prefer microfarads but some cultures prefer nanofarads, and 2.2 microfarads is indeed 2.2 thousand nanofarads.

KSC is King-Sun, but their website sucks, and the date code indicates that these were manufactured in 1986, probably march if we can assume that they are using year-week date codes which is common in electronic components, though some use year-julian-day which would mean 2nd week of january.

NP is obviously non-polar, rated at 85 degrees C, M07 is probably the product line.

Not sure why they would put a Y after the voltage rating rather than a V. Asians are weird sometimes?

Like i said I'm a lot less sure about the inductor. If that's a plastic bobbin it's way small for 68uH if we compare, to, say, Madisound's product:

http://www.madisoundspeakerstore.com/air-core-20-awg/madisound-0.67-mh-20-awg-air-core-inductor/

If that's a ferrite core, it may look about right. Hard to find ferrite-core bobbins for DIY crossovers but there is a 1mH ferrite bobbin inductor in my L520 crossovers from the factory.

C could be for Ceramic (ferrite is a ferroceramic) and we could decode it as C-68-1k for ceramic 68 thousandths of a henry.

I'd get out my LCR and measure the lot of it but failing that, those are my assumptions.

 

[ouimetnick]

Well, the values make sense as well.

It's odd marking but for example a 2.2ohm resistor is often referred to as 2R2.

In the USA we prefer microfarads but some cultures prefer nanofarads, and 2.2 microfarads is indeed 2.2 thousand nanofarads.

KSC is King-Sun, but their website sucks, and the date code indicates that these were manufactured in 1986, probably march if we can assume that they are using year-week date codes which is common in electronic components, though some use year-julian-day which would mean 2nd week of january.

NP is obviously non-polar, rated at 85 degrees C, M07 is probably the product line.

Not sure why they would put a Y after the voltage rating rather than a V. Asians are weird sometimes?

Like i said I'm a lot less sure about the inductor. If that's a plastic bobbin it's way small for 68uH if we compare, to, say, Madisound's product:

http://www.madisoundspeakerstore.com/air-core-20-awg/madisound-0.67-mh-20-awg-air-core-inductor/

If that's a ferrite core, it may look about right. Hard to find ferrite-core bobbins for DIY crossovers but there is a 1mH ferrite bobbin inductor in my L520 crossovers from the factory.

C could be for Ceramic (ferrite is a ferroceramic) and we could decode it as C-68-1k for ceramic 68 thousandths of a henry.

I'd get out my LCR and measure the lot of it but failing that, those are my assumptions.

Don't have a LCR meter. Anyways the inductor is a little heavy. The thing the wire is wrapped around is definitely metal, so it would be a ferrite core I think.

 

[ericj]

Don't have a LCR meter. Anyways the inductor is a little heavy. The thing the wire is wrapped around is definitely metal, so it would be a ferrite core I think.

Well, it seems likely then.

If they were my speakers I'd replace the caps and leave the inductors alone, but i have a LOT of good (to my ears) film caps around so i could do it on a whim.

Some may say that a laminar iron core inductor would sound better than the ferrite core, and I don't really know about that, but you could certainly replace the inductors if that's what you want.

Maybe there is an electronics store in your area that caters to students and small businesses that might have an LCR behind the counter that they could measure the parts with? Of course, they would hope that you buy the caps from them for their trouble.

 

[Copa1934]

Well, it seems likely then.

If they were my speakers I'd replace the caps and leave the inductors alone, but i have a LOT of good (to my ears) film caps around so i could do it on a whim.

Some may say that a laminar iron core inductor would sound better than the ferrite core, and I don't really know about that, but you could certainly replace the inductors if that's what you want.

Maybe there is an electronics store in your area that caters to students and small businesses that might have an LCR behind the counter that they could measure the parts with? Of course, they would hope that you buy the caps from them for their trouble.

Dang, that's actually a cool suggestion. Many schools do still have electrical/electronics type courses and may have the equipment to do tests. Cool!

 

[ouimetnick]

Well, it seems likely then.

If they were my speakers I'd replace the caps and leave the inductors alone, but i have a LOT of good (to my ears) film caps around so i could do it on a whim.

Some may say that a laminar iron core inductor would sound better than the ferrite core, and I don't really know about that, but you could certainly replace the inductors if that's what you want.

Maybe there is an electronics store in your area that caters to students and small businesses that might have an LCR behind the counter that they could measure the parts with? Of course, they would hope that you buy the caps from them for their trouble.

I'm just going to keep the original inductors, and replace the caps with some Dayton Audio ones.

 

[ouimetnick]

Dang, that's actually a cool suggestion. Many schools do still have electrical/electronics type courses and may have the equipment to do tests. Cool!

I'll ask an electronics teacher when school begins.

 

[ericj]

Dang, that's actually a cool suggestion. Many schools do still have electrical/electronics type courses and may have the equipment to do tests. Cool!

Yeah, and some universities have their own supply stores for the schools of engineering, physics, etc.

The universities in my area have their own physics and chemistry supply stores but depend on a local business to provide for their EE courses.

Central Utah Electronics. In business since the 1930's and have the old stock to prove it.

 

[bowtie427ss]

I'm just going to keep the original inductors, and replace the caps with some Dayton Audio ones.

Perfect!:thmbsp: