My New Speaker Project: Advice Requested Options

[genek]

In this case it's not so much about testing coils and caps for correct values, but just seeing if there's a break in the circuit. A common VOM would probably be sufficient for that. But a wiring error or bad solder joint are definitely more likely. I think what I would do is just fire up the iron and reflow the joints in the MR portion of the crossover, making sure that all the soldered bits are clean as well.

[JKent]

Those big coils of wire are the inductors and there's really nothing to go bad there BUT as Roy said, if you disconnected one and then re-soldered it, that could very well be the problem. I learned that through personal experience . The wire in that coil is insulated with a thin coat of very tough varnish. If you need to solder it, you MUST scrape and sand the varnish off to get down to clean shiny copper, then solder. I have not worked on a 3a, just the 2ax and 4x, so I'm not sure whether the work you did involved disconnecting the inductor coils, but if it did that is the most likely culprit.
Kent
PS An LCR meter is handy for checking caps. Roy gave you a link to a nice one but you can find them on ebay, from Hong Kong, for half that price. If you will use one infrequently that may be the way to go. But check that inductor solder joint.

[soundminded]

I am hoping it is just a wiring error. I will check the driver first with a meter before taking the speaker apart again. Of course, I really, really hope it isn't the driver. I am somewhat hopeful, since this pair of speakers appears to have spent its first forty years being well cared for in the home of someone who listened primarily to classical music. Perhaps I'll know as soon as tomorrow.

Thanks again.

Check to see that you have reassembled the midrange potentiometer correctly. Be certain that you haven't re-installed the moving contactor upside down, it's an easy mistake to make. If it is upside down with the short contactor facing away from you, it will not make contact with the fixed center contactor when you re-assemble it. It is also easy to misorient the two assemblies when you put them back together so check that too.

[danajohnhill]

Ahhh! I did disconnect one of those solid copper wires when I took apart the mid-range pot. In fact, I think I initially clipped it, meaning the part that I re-soldered might still have that coating on it, preventing a good connection. I am going to sand the wire down and reconnect it.

Fingers crossed big time!

[ar_pro]

Dana -
Be sure to check continuity on the choke before re-soldering the connection - you want to be certain that you've removed enough of the insulating varnish, and will have a solid mechanical & electrical joint.

[danajohnhill]

SUCCESS!

Sure enough, it was the coating on the inductor wire. I had clipped off a quarter inch of that wire when I first removed the mid-range pot to clean it, and, not realizing it was coated, I simply re-soldered it. It wasn't making an electrical connection.

You guys are amazing. I would never have thought about that plain-looking copper wire causing me a problem. What's more simple than a bare copper wire? I owe you all a Coke.

As I type this I am listening to one of my favorite non-classical albums, Jackson Browne's For Everyman, and it sounds magnificent. I have never heard any bottom end on this record until now. Next up is the remastered Born to Run.

I guess my project is complete. For the record, I was able to keep every original component of these speakers except the gray sealant putty. I replaced the capacitors but left the originals inside. After re-sealing the cloth surrounds on the woofers, all the drivers are now perfect and original. After cleaning, the original pots are perfect. All the wiring inside was retained. Since the capacitors were a gift, the only money I spent was $9.05 on the gray putty (including shipping), and $7.48 on the Permatex (including tax). I did buy a multi-meter, and wire strippers, but I needed those anyway. All the other stuff--solder, etc., I had already.

Once again, my profound thanks to all of you, and to the authors of "Restoring the AR-3a". I now have a great set of for-life speakers.

[JKent]

Excellent! Believe me, I know from experience what it's like to overlook something "obvious" and to be bailed out by members here! Enjoy those beautiful speakers but please don't rub in the fact that they cost you $16



Now.... if you ever feel the need to tinker some more or if you have some money burning a hole in your pocket you might consider upgrading the caps from the cheap NPEs (non-polarized electrolytics) to some quality film caps. You have a 150uF, a 50uF and a 6uF. The 150uF is expensive (Solens are $41 each) so you might want to leave the NPEs but the smaller values are reasonable. 50uF Solens or Daytons are under $15 each and 6uF Carli mylars are just a buck fifty (Solens and Daytons are just a little more).

The original caps were electrolytic, and the replacements you have are fine. But most audiophiles here would opt for some variety of film cap: Dayton and Solen are the most popular inexpensive caps. Beyond those, prices can go sky high.

If you decide to go that route, ask questions here. You'll get lots of help and LOTS of opinions.

Happy listening
Kent

[sidecar]

Not removing enough of the enamel coating from the inductor wire before re-soldering is a common oversight, resulting in a bad connection. That would be the first area to check out. Another area to examine is the wire resistor in the midrange circuit. I doubt your issue is related to defective caps or inductors. The pot section of the circuit is the usual culprit, even after cleaning and re-installation.

If you intend to test caps and inductors, an "LCR" meter of this type is very helpful:
http://www.mcmelectronics.com/product/TENMA-72-8155-/72-8155

Roy

Hi,
I,m restoring a pair of AR5 and same problem arises for hi-range driver, due at an incorrect thread connection. In my case the hig driver is phase-inverted and in final mounting I've mis-matched this connection.
It is possible for you exchange the drivers? Only in this case, imo, you can exactly know if no-voicing dome is damaged. Obviously putting non voicing dome in voicing circuit, not vice-versa!
Sorry for my bad english.


Greetings from Rome

Claudio

[RoyC]

Hi,
I,m restoring a pair of AR5 and same problem arises for hi-range driver, due at an incorrect thread connection. In my case the hig driver is phase-inverted and in final mounting I've mis-matched this connection.
It is possible for you exchange the drivers? Only in this case, imo, you can exactly know if no-voicing dome is damaged. Obviously putting non voicing dome in voicing circuit, not vice-versa!

Greetings from Rome

Claudio

Well, greetings from New York, Claudio...

I'm not sure I completely understand your question, but I think the short answer is yes, you can "exchange" drivers. Polarity/phase differences will not affect your ability to test or exchange drivers...nor will these differences be the reason for a non-functioning driver.

Roy

[sidecar]

Well, greetings from New York, Claudio...

I'm not sure I completely understand your question, but I think the short answer is yes, you can "exchange" drivers. Polarity/phase differences will not affect your ability to test or exchange drivers...nor will these differences be the reason for a non-functioning driver.

Roy

Roy,
my intention was to give a little advice to Dana for his not-working driver. My mistake was not have read secon page of this tread where the problem was solved. thanks anyway for your clarification.

Rgds,

Claudio

[Steve F]

Claudio,

My daughter lives in Perugia. She is fluent in Italian (she works for an international marketing firm and does English-Italian translations as part of her work). If you have a complicated situation or problem that you can't explain in English, send it to me in Italian through this web site's message service and I'll ask my daughter to translate it into English so the rest of the Forum can respond. She has translated many Italian items already, including a recent Tim Holl interview.

Steve F.