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Dynaco A-25 Restoration

Theabea

Theabea

New Member
Hi all—

This is my first time posting on the forum. I just bought a pair of used Dynaco A-25s at an auction. They sound great, but have light discoloration (pictured below) and are missing a grill cloth and frame. I found a great fabric match as well as the Dynaco name plates. This will be a fun project, but I’m relatively inexperienced.

Two questions:

-Does anyone have any experience rebuilding the frames? I would be interested in any pictures or wood recommendations.

-For addressing the discoloration, is there a recommended stain?

Many thanks,
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@Theabea

I see you joined today so welcome to AK and here's hoping you enjoy your time here.

The Dynaco A-25 is a very popular speaker here on AK and the forum is rife with all sorts of restoration, upgrade, etc threads

If you look below there is a section titled "Similar threads" which would be a start to looking for information.

AK also has a great search engine, which is in the upper right hand corner. Type in "Dynaco A-25" and you should find a myriad of threads that should help you get more info about what it is you are trying to accomplish.
 
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I made grille frames from 1/4" hardboard, masonite. The new grilles sit almost flush with the cabinet, not recessed much but the frame is stronger.

The speaker was an oiled walnut. I use a rag well soaked with acetone to wipe the speakers clean of 50 years worth of old dirt infused original oil used for that finish. Don't put the acetone on the speaker, that puddle will clean more than the rest of the speaker as acetone is a very good cleaner of the stuff on the speaker.

Then Watco Danish Oil Finish in light medium or dark walnut. I usually use dark as the speakers get lighter over the years and will the acetone cleaning. Couple coats then after fully wiped off and dried, Howard's feed and wax as needed to provide a nice rich oiled walnut look to the speakers.
 
Dswankey said:
@Theabea

I see you joined today so welcome to AK and here's hoping you enjoy your time here.

The Dynaco A-25 is very popular speaker here on AK and the forum is rife with all sorts of restoration, upgrade, etc threads

If you look below there is a section titled "Similar threads" which would be a start looking for information.

AK also has a great search engine, which is in the upper right hand corner. Type in "Dynaco A-25" and you should find a myriad of threads that should help you get more info about what it is you are trying to accomplish.
Click to expand...
Thanks for your welcome and orientation! I’ll check out the threads!
 
Blue Shadow said:
I made grille frames from 1/4" hardboard, masonite. The new grilles sit almost flush with the cabinet, not recessed much but the frame is stronger.

The speaker was an oiled walnut. I use a rag well soaked with acetone to wipe the speakers clean of 50 years worth of old dirt infused original oil used for that finish. Don't put the acetone on the speaker, that puddle will clean more than the rest of the speaker as acetone is a very good cleaner of the stuff on the speaker.

Then Watco Danish Oil Finish in light medium or dark walnut. I usually use dark as the speakers get lighter over the years and will the acetone cleaning. Couple coats then after fully wiped off and dried, Howard's feed and wax as needed to provide a nice rich oiled walnut look to the speakers.
Click to expand...
Fantastic recommendations! I’m hoping to get this finished over the weekend. Did you glue or Velcro the frame?
 
Velcro and made a tab of grille cloth to stick out at the bottom as a pull to remove the grilles.

Afterthe acetone wipe down, raise any slight gouges with a damp rag (water) and steam with an iron, a minute or so. When dry sand with 220 or higher to smooth whole speaker, wipe with acetone again to remove dust and finish once dry.
 
I used Watco's Dark Walnut Danish Oil. Super easy to apply with a simple rag, just wipe off the excess.
Careful when sanding, the veneer is paper thin.
 
Oh and take the woofers off and look at the terminals. Many A25s had issues with the woofer terminals falling apart.

Another A25 restoration thread

Just a few pictures of my ongoing work on my recently acquired A25XLs. Some scratches, some water marks. Most seems to have disappeared with a careful 220 grit sanding. I'm thinking Watco's Danish oil as a finish. I don't necessarily want them back exactly like were when new, but now that I've...
audiokarma.org
 
CarlQB said:
I used Watco's Dark Walnut Danish Oil. Super easy to apply with a simple rag, just wipe off the excess.
Careful when sanding, the veneer is paper thin.
Click to expand...
CarlQB said:
I used Watco's Dark Walnut Danish Oil. Super easy to apply with a simple rag, just wipe off the excess.
Careful when sanding, the veneer is paper thin.
Click to expand...
Good to know! Are all A-25s veneer or are any solid wood? Thanks in advance.
 
They are veneers. You are not sanding them down to remove gouges, this will rip through the veneer. You are sanding only to make them smooth. The gouges were steamed to lift the wood and what didn't lift is a beauty mark in your personal pair of A25s.

It is a toss up as to hand sanding or using a powered palm sander, something designed for finish sanding. You don't want to remove much, just get the surface smooth.

Looking for pictures tomorrow since you said this weekend. We like pictures.
 
Hello A-25 fans, This looks like the most recent thread on A-25's so thought I'd join in.

Theabea - Not replacing the capacitor? That's pretty S.O.P. if your opening up things, although with the Dynaco's, the speakers are harder to remove than most. Very sticky sealant, like pine pitch or something. It's doable though.

General questions - I have a very early A-25 with the 25VT-EW woofer and 87H tweeter - both are SEAS. The tweeter date is 16 69, the woofer is 10 69 fwiw.
The crossover configuration is - from the capacitor to the resistor in the upper left - Jensen 5uf 50WVDC, 2.2 ohm, 2.2 ohm, 3.9 ohm, 4.7ohm, 2.2 ohm, 4.7 ohm. All resistors are 3W as best I can tell.

I've never seen any A-25 crossover schematic posted anywhere like these. Anyone have an idea what's going on? Other than I've seen comments that Dynaco had various configurations early on until they ended up using the 2.2 ohm resistors and one 10 ohm as the last one.

I'm thinking to find another matching Jensen 5uf cap, probably electrolytic. Or go big and use something other than Dayton poly caps or any poly caps for that matter.
Will probably leave the resistors in for now.

Thanks for any comments.
 

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Well, I have two pair, so I'll try to keep one pair as original as possible and update the second to match the crossover to the latest schematic to which you kindly sent the link.
 
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