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Dynaco A25 Woofer sounds like a Kazoo

R

rickdean

New Member
Just bought a NEW pair of Dynaco A25's that were stored in a closet for 30 years. Nice original boxes and beautiful speakers. All was great until I realized 1 woofer has issues. Sounds like a Kazoo and kind of Raspy. Removed both grilles for comparison and it appears the one that is making noise does not move in and out as smoothly as it brother. Cannot hear any scratching noise when manually pushing the driver in and out. Is it a bad voice coil?

Should I Ebay a used woofer or or send it for repair? Its a 25 TV-EW. Comments appreciated.
 
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You'll have to gently pry it out of the box first to check it. Be careful as the woofer is screwed and glued in IIRC. The wood that its screwed to is also somewhat thin so careful with any prying tools. Before you pull the woofer, mark which edge is up and down. You'll need to know that.

Once you have the woofer out, inspect for any type of debris around the voice coil area. Inspect for any loose filling inside the cabinet. Inspect for any loose wiring or crossover element which might be buzzing or loose. Check the back terminals to see if they are also tight. Check woofer for any obvious problems with suspension, spider or voice coil. You could then try rotating the woofer 180 degrees and reinstall and see if there is any improvement as the suspesion/spiders may have sagged after all these years.

Good Luck!
 
Same problem I had with one of the pair I picked up. The voice coil is more than likely toast. I dropped in an e-bay replacement and all has been well.
 
It very well may be toast. Check to make sure surround hasn't come loose from driver frame. I had an AR woofer that had that problem and it was simple reglue fix.

If you have to remove/replace you may want to consider trick Zilch taught me. Glue some fresh wood pieces behind the baffle so screws have fresh wood to catch and hold woofer firm.

Might as well do both and recap while in there. I replaced binding posts on my second pair and they do sound better. Those original posts are for the birds. :yes:

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BTW if you need new woofer not that some are smooth/round on outer edge and some like mine have ears where screws are. You need to match what you have.

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I see in the pictures above a new cap was installed, but there seems to be another smaller cap also. Whats up with the dual cap installation? I was going to use partsexpress #027-232 for my A25 caps'. Comments appreciated.
 
My Dynaco A25's have 25TV-EW woofers. 1 is bad. Could I use the newer style 25F-EW woofer? Seems like there are more of them available.

Comments appreciated.
 
OP says these were new, if that is true then I wonder what could be wrong? If the spider has sagged badly enough that the VC is off center, then I wonder if he could lay the speaker on it's back and try playing music through it again, albeit very low signal.
 
My woofers are the 25TV-EW's. The newer A25's used the 25F-EW's, would these work in the older model? Aside from the screw pattern being different am I missing anything else? Seller said they were in the original boxes and his family since 1972. Original Dynaco Boxes are probably worth more than the A25's they held!

Comments appreciated.

Rick
 
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rickdean said:
I see in the pictures above a new cap was installed, but there seems to be another smaller cap also. Whats up with the dual cap installation? I was going to use partsexpress #027-232 for my A25 caps'. Comments appreciated.
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I used some Russian Military bypass caps in addition to the Parts Express. IT's not necessary and I did it mainly becasue I had them. Some say they add air and reduce hysteresis. It is debateable.

I think the new binding posts made more of a difference.
 
I have noted the 25TV-EW came either with the "ears" for screws or smooth round. I believe the smooth round came into production in 1973-74 and previous to that the "ear" versions were used. Comments and corrections appreciated.
 
Bang & Olufsen used Seas woofers in many of their applications. You might find a sleeper auction and save some $$$ using them in your search.:scratch2:
 
I have 2 of the 10" Seas 25TV-EW, one with 6 ear holes and the other is round/edge with 8 holes. The round edged has a bigger/larger spider and is dated 1974. The 6 ear hole is dated 1973. Looks like the later round model might have a better response with the larger spider allowing for more movement. The magnet is the same on both.
 
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