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Dynaco A25 rehab - a work in progress

wiredbecker

wiredbecker

...jams ECONO!
Subscriber
Picked up 3 free mostly driverless Dynaco A25s a couple weeks ago. I've sourced original woofers... probably get the Seas replacement tweeters from Madisound. Caps are on the way from PE. Two of these will be fixed up, paired with a ST35 and given to my wife for Valentines Day.

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As you can clearly see, my work is cut out for me. After a quick call to my dad I picked up some environmentally friendly orange-based stripper and got to work. Everything went so well that I forgot to take pictures. Check out that beautiful walnut veneer that used to be painted black!

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Here's a view of the less damaged cabinet

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Alright, so I'm back on track here applying the stripper to edge so you can see how easy it is to remove.

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The paint is coming off like a knife scraping butter from toast. Nasty dirty butter. As soon as this stripping process is complete, then I break out the #3 or #4 steel wool and get to sanding.

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So yeah, my work is cut out for me. This houseplant induced water stain is probably the reason why the previous owner painted these puppies black in the first place. Well that and a lack of good aesthetic judgment. Wish me luck. I have many hours of sanding ahead of me. If you have any speaker rehab advice, let 'er rip!
 
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Good job!

You have the uncommon advantage of making a mirrored pair there. I can't recall which was the lower production numbers, but one of those, with the tweeter located differently than the other, is an uncommon one.

I too, have three orphans, and one of them is the uncommon mirrored as well.

We should keep in touch, because I'm restoring mine, and have a lead on original parts- possibly more than I'll need. Maybe I can help you out with your resto.

Paul
 
You'll be glad to know that the walnut veneer is pretty thick. I bought a pair in a garage sale a few years back and both speakers were badly scratched. Some so deep that I thought for sure I'd go through the veneer. As luck would have it, I was able to sand out all of the scratches. I then applied a walnut stain and finished with a couple of coats of satin polyurethane. Turned out great. Good luck with yours.

Cheers
 
I must have your missing orphan. I have one of those someone also felt the need to paint black. looked for its mate for a month then threw it in the orphan pile.
 
Whoa cool, I can't believe I didn't notice I had a mirrored pair! I guess I was just so hyped to get cracking on this project.

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wiredbecker said:
Whoa cool, I can't believe I didn't notice I had a mirrored pair! I guess I was just so hyped to get cracking on this project.

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Cap values can change within the run- the miss-matched (but then that's a bonus- you've got mirrored!) cabs I've run across have different cap values in the crossover. So be sure to make sure with these you get the crossovers to match correctly.
 
So I'm under the gun to get this done by Thursday for Valentines Day. Wish me luck, I'm going in.

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Now's my chance to label these wires so I can properly hook up the new drivers.

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Check out this re-coned 25 TV-EW Woofer! The paper surround just peels away. Maybe I'll learn to refoam on this backup driver. Any idea where I can get a replacement rubber surround?

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And now we get to the heart of the matter. The crossover. I wonder if that Jensen cap is still good? No matter, I have replacement Solens to install.

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Well what do you think, should I install all new resistors while I'm here?
 
I would just meter each one and see how close to tolerance they are. Mine were all within 2 to 5% so I didn't mess with them. I only dropped on a new cap in each speaker and changed the wire to new 16ga. I just had tons of extra wire...it was something to do.
 
Excellent choice for a rehab. I love the A25 to an irrational extent. Keep the R's and toss the C in the crossovers. A decent quality film cap is all you need there. Nothing exotic.
I have a pair of those that a neighbor gave me. He bought them new overseas and eventually painted them black. They were teak, which I understand is a rarer finish.
Some time ago I rehabbed and sold a pair of the A25XLs They have a slightly different and somewhat superior tweeter.
Fixed up correctly, the A25 is one of the top 5 available vintage speakers.
 
I've got the A25XLs in my main system! I keep trying other speakers but they A25XLs always return in no time.
 
I have a pair of A25XL's that I sanded down a couple of weeks ago and am having to wait for the weather to warm up so I can finish refinishing them.
 
It's easy to spend someone else's time by recommending that they do a time consuming project, but I have no doubt that rehabbing a pair of A25s is worth the effort.
After all, it's not like a pair of L300s or something.
The sound benefit is definitely worth the time and elbow grease, which is not always the case with every rebuild.
 
There aren't too many vintage speakers on my short list anymore, but the A25 is right there.

One of these days I'll find a pair....
 
specialidiot said:
There aren't too many vintage speakers on my short list anymore, but the A25 is right there.

One of these days I'll find a pair....
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All you had to do was look in my basement yesterday.

Done in Makoree and one of my favorite vintage speakers.
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Keep up the great work. You will be rewarded in the end.
 
hehe...same here. We are all in the same neck of the woods as well. ive been on the hunt but havent found anything....

Im hoping they will start popping up come springtime.
 
specialidiot said:
There aren't too many vintage speakers on my short list anymore, but the A25 is right there.

One of these days I'll find a pair....
Click to expand...

I read a statistic somewhere that over 500,000 pairs were sold. According to people I know who were selling audio in the early '70s they would receive truckload shipments consisting entirely of A25s and nothing else. They were also sold for a long time. This makes it very likely that not only will you eventually turn up a pair, but that you'll get your choice and the price will be decent. Put the word out with locals who turn up old audio stuff and a pair with your name on them will appear sooner or later. They're worth the wait and the work.

I love fooling with old speakers. Today I finished grafting together two of my favorites: AR3's and LS3/5As. I call them AR3/5as. They're the cabinets and woofers of the AR3s, with the mid, tweeter and upper crossover replaced with LS3/5A parts. A horridly expensive way to create a heavy, insensitive speaker with limited dynamics, but what the hell. It was too cold to go out and play outdoors so I stayed in and got into trouble in the shop.

There's very little that's as rewarding as working on speakers. Tube amps come close on the satisfaction scale, but with speaker projects you don't have the fatal high voltage factor.
 
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I heard it was something like 600,000 world wide that were sold and that made it the best selling speaker of all time in quantity. I read this plus heard it from dealers that sold them back in the day. Anyone know this for fact or fiction?
 
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