Dynaco A25 Curve Ball

Recently received a pair of Dynaco A25 from the original owner. They were in fact on a bookshelf for 40 years. The surrounds are really in fantastic and flexible condition for being so old. The tweets are glossy and clear under the screen and they sound pretty good.

However upon opening up both speakers noticed one had the wire coming thorough the woofer and the other just has two dots. The magnets were a little different too.

Was expecting to find 5uf or 8uf (xl) Capacitors. However found they both have square 4.7uf capacitors. (4.7uf /10/100.

These are original as the covers were glued on and very hard to remove. Plus the leads to the Caps are very short, would be impossible to get a soldering iron down there with any degree of accuracy.

Anyone ever seen an A25 with 4.7uf caps? Going to look for some 4.7 or think I should go for 5uf as most of the other A25s? Perhaps they changed for a period of time to give a different profile. Anyway here are some pics, comments welcome.


Donny

Sorry here is the woofer with two dots. Accidentally posted a Pic is of my non-magnetic screwdriver.

Donny

Are those two dots or two eyelets?

I'm wondering if you actually have the A25XL model because it looks like you have the later smaller tweeter with the mesh grill rather than the 1.25" larger tweeter. That may account for the smaller cap value.

You have the A25 speakers (5 position level switch on back). The woofer is not the normal woofer. Does it say SEAS on the back of it, cast into the basket (you'll have to take it out to find out).

mech986 said:

Are those two dots or two eyelets?

I'm wondering if you actually have the A25XL model because it looks like you have the later smaller tweeter with the mesh grill rather than the 1.25" larger tweeter. That may account for the smaller cap value.

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The woofers are the ones used in the A-35, which are higher efficiency than those in the A-25, which have eyelets instead of the round flange. I'm guessing you are right....

I don't think they are. The woofers look like a newer pair from SEAS like the ones I bought about 6-7 years ago. Does the cone paper kind of a purple tint to it? Also, the usual stain around the dust cap is missing. Every Dynaco speaker that I've worked on or have seen has the stain on the paper cone, around the dust cap.

I wouldn't sweat it. Seems like Dynaco was the ultimate parts bin kind of outfit. They were just using whatever they could source cheaply in volume.

Dadbar said:

I wouldn't sweat it. Seems like Dynaco was the ultimate parts bin kind of outfit. They were just using whatever they could source cheaply in volume.

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With over half a million of these things made, they had to use what they could find at times.

Those caps are probably fine. Not electrolytics.

Blue Shadow said:

With over half a million of these things made, they had to use what they could find at times.

Those caps are probably fine. Not electrolytics.

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That block type cap construction is very typical in European speaker xo's. They are either polyester or PP film and are very stable. I don't think 4.7uF vs 5.0 is a deal breaker in a dynamic, music-reproducing loudspeaker.

Id agree its original because if the 5 uF was changed, you would see the green glue they used to use to hold it down, there doesn't appear to be any residue from that.

Wayne

Yes they both say Seas on surrounds but one barely fits in the cab and the other has different
screw holes. Spoke with my father in law the original owner and he said he bought them together, same store and same box when new. Yes 5 position level switch. They sound wonderful.

WaynerN said:

You have the A25 speakers (5 position level switch on back). The woofer is not the normal woofer. Does it say SEAS on the back of it, cast into the basket (you'll have to take it out to find out).

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So you guys don't think the caps need replacing after 40 years. My father in law bought these way back in the 70's. I have seen these speakers sitting there for the past 32 years. Donny

When the grills are in place, they are typically recessed slightly on A-25's. If they protrude beyond the edges of the cabinet, then they're A-25XL's. Also, at least in later years, the grilles were not glued on.

Sure hope my memory's not faulty.

Octave

They were glued on, really well I might add. Think some of the other comments are accurate. they were using several woofers during production and my Father in law just got one slightly different than the other. My question is should I change the Caps?
Thanks
Donny

Octaven said:

When the grills are in place, they are typically recessed slightly on A-25's. If they protrude beyond the edges of the cabinet, then they're A-25XL's. Also, at least in later years, the grilles were not glued on.

Sure hope my memory's not faulty.

Click to expand...

I would leave the caps alone. Get things back together and take a good listen. If you like what you hear, leave the caps alone.

Those speakers were well taken care of. If they had been in a attic or damp basement for 20years different story with the caps.