• The move to the new server is done. There are some software and database maintenance updates in process. This has us passing the hat around to help out. We appreciate any donations. Seriously, even a dollar helps. The payment page may be found here - https://www.audiokarma.org/support.html

Dynaco A10 woes

desertmirage

desertmirage

New Member
Hi!

First post, after using this site for reference sooo many times. Helped me rebuild some KLH model 6's-thanks AKers!

I picked up a pair of what I though we're just ugly, crappy small speakers, went ahead and spent the 4.99 for both, and scored! Dynaco A10's!
Refinished them and I (and my wife because they are small) love them! They sound amazing for their small size!

So had the opportunity to get another set from CL for <gulp> 65.00 and picked them up-and violated a cardinal rule-didn't hear them before buying them. Hooked them up, and 1 of the woofers wasn't working. (Sad face here)

Took it out, 0 reading on an ohm meter, and because I don't trust myself, did the battery test, nothing.

I think this means there's a short in the wire wrapping-burned from an overload?

Finally, the question where I can use some help-

Can these be fixed? Or-
A. Try to find a replacement online, from an already fairly rare speaker
B. Replace it with a new one
C. Sell them? Cabinets are in great shape-dark walnut
D. Any other test to confirm its dead?

I don't exactly need them, but have a strange bond with these little guys.

Thanks for any input you folks can give. I'm just not sure how to proceed.
 
Register to hide this ad
If you decide not to replace the woofer, at least you have spare tweeters and a woofer for the working pair.
 
I had a pair of A10 for a while. They are the only speakers I have had that my wife complains about me selling:)

If you hold out long enough you might be able to find a replacement woofer on ebay. I would keep them and hope for that:

Also have you verified its not something simple like the tinsel wire is loose from the terminal. These drivers are known for coming apart in that area. I would try to get a reading with the multimeter on the wires right up by the cone to make sure it really is blown.

Good luck!
 
Oozure, thought about that. Keeping spare parts is a great idea, but trying to curb my audio gear hording tendencies. But, may do that.

Elitopus-I did test on the wires, hoping maybe just a terminal was bad. It looks like somebody else may have been inside-one of the wires was soldered directly onto the the silver wire going to the speaker.

I don't trust my troubleshooting skills.

MM set to Ohms, when I touch the wires, reads 0, no numbers change. When I used a battery and touched the contacts, and the bare wires going into the cone-nothing.

Can I rule out user troubleshooting error? Can they be fixed?
 
Post some detailed pictures of the woofer and its connections to voice coil and spider etc. Then the community can chime in on what might be wrong potentially.
Neat little speakers for sure.
 
Your first picture of the woofer makes it look as though the magnet has shifted. Does the cone move freely if you push on it with your hand?
 
Both those woofer connections look wonky. I would start with my meter and check the continuity at each point starting with the burnt looking +red connection.

I would probably cut the wires and unsolder that mess and start over. Then you can know for sure if it will ohm out or not from the connection through the voice coil wire etc.
 
Thanks for these troubleshooting ideas. For some reason I don't want to believe it's burnt.

The cone did move freely, I listened to it to see if I could hear any rubbing or crunching, but not close enough, so I will.

I'll also cut the small wires at the terminals so I can test them without the mess at the terminals. I hope it can be that easy.

Thanks for the tips and ideas! That's why I love this site. I'll update you tonight.
Thanks!
 
Ok, update-
I u soldered the voice coil leads from the terminal, finally got an ohm reading, but it was very sporadic, 1.5-4.

Did the battery test, no movement.

Then I thought, my wife can hold the battery!

Held the wire from the battery to the detached vc leads. Nothing. Touched the vc wires as they go through the cone- noise!!!!!

Not dead! But I have a bad vc wire right at the point it enters the cone.

Now what? Can that be fixed by a novice?

Thanks for all your help getting me to this point!
 
Sounds like the flex wire going to the voice coil wire is badly corroded. The solid voice coil wire is seen from the front side and, with skill, a good soldering iron and some flex wire (perhaps from another speaker), will fix the beast. I have repaired this wire on my Dynaco A25XLs. ( I have also been watching this thread with interest, hoping that this would be the problem rather then fried voice coil wires. No scraping with cone movement is another good sign).

Once in awhile, a guy just has to put on the "big boy" pants and go after a problem (once it is correctly diagnosed). You might as well try fix it because the speaker is useless in its current condition and sending it to a re-cone company would cost lots. Use an Exacto knife to dig out the solid VC wire, solder some new flex to the speaker terminal post and it will be good.

'ner
 
One more thought. I've worked on many of these woofers. The terminals are known to fall apart. One reason that the battery test may not be working is that both terminals may be shorted together from the input wires touching the frame. You may need a small mirror to examine the condition of the terminals on the inside of the cast speaker basket. The flex wire might be just corroded on the outside of the wire but still capable of passing signal. I can see that the flex wires to the terminal are badly corroded. they will need to be cleaned and re-soldered as well.

'ner
 
Ok, so where the flex wire enters the cone, there's a dab of -epoxy?

Scrape off the epoxy blob and solder on another piece of flex wire to the existing wire, past the point where it enters, and appears to be the failure. Is that correct?

How much give is there in the wire once it goes into the cone? Can I pull it out some to insure I solder past the corroded part?

The terminals are pretty jacked, should I replace them?

Thanks for the advice!
 
WaynerN said:
One more thought. I've worked on many of these woofers. The terminals are known to fall apart. One reason that the battery test may not be working is that both terminals may be shorted together from the input wires touching the frame. You may need a small mirror to examine the condition of the terminals on the inside of the cast speaker basket. The flex wire might be just corroded on the outside of the wire but still capable of passing signal. I can see that the flex wires to the terminal are badly corroded. they will need to be cleaned and re-soldered as well.

'ner
Click to expand...
So I need to scrape the black compound away from the top of the speaker connecting the VC lead with the flex wire. Same on the bottom, and run a new wire back to the terminal? Is that connection soldered?

Is that the right approach to bring it back?

Could I try to apply a small amount of solder where the interruption is at the cone, or is that a bad idea?
 
From those photos, the flex wire looks pretty good. Your problem might be at the terminals after all........

Here is a photo of how I fixed my woofers

:IMG_0276.JPG

'ner
 
The terminals on mine look pretty beat up. I would say someone has desoldered them several times.

The wires do look good, but the only way to get them to move with a battery is if I touch the lead on one of them right where it goes into the cone.
 
Getting rid of those terminals is the best thing you could do for these and will solve the problem more than likely. At least you take that potential issue out of the equation and you can dig deeper if it does not.
 
You must log in or register to reply here.
Back
Top Bottom