Questions on a pair of AR3's.....

[lakecat]

I picked up a pair of AR3's today and are in little rough condition. I removed the woofer and insulation to expose the crossover to see what I needed to get.

I am so used to the 3a's that I have 6,50, and 100 uf on the brain. Can someone tell me what caps I need for this? And what to do with the blue common wire?

I also noticed that to front section of wood that always 3/4" thick...isn't on this pair. It has a front face that is about 3/8" at best. I showed it in pics. I had never seen this before. Did they do this for awhile? It has serial numbers in the 65k range.

I noticed also that the insulation in cab was just centered around woofer and over crossover but absent on cab up inside for the mid and tweeter area. Was that common also? I have been the first into these cabinets so I know it came from factory this way. Thanks for any help.

[ra.ra]

Great looking speakers - - - walnut or mahogany? For crossover ID, perhaps you should begin by digesting the appendix in the AR-3a restoration manual titled "AR-3 Crossover Schematics", which outlines the history of x-o variations with several schematic diagrams. The blue (BE) common wire shows up in each one.  

[lakecat]

11 hours ago, ra.ra said:

Great looking speakers - - - walnut or mahogany? For crossover ID, perhaps you should begin by digesting the appendix in the AR-3a restoration manual titled "AR-3 Crossover Schematics", which outlines the history of x-o variations with several schematic diagrams. The blue (BE) common wire shows up in each one.  

Those are walnut. I feel so stupid...as I never noticed the section for the AR3 crossover breakdown. Thanks for pointing that out. I just forgot the blue ties in to both caps. Other odd thing is the facing on these cabinets and the stuffing only being centered around woofer and crossover with nothing in upper cabinet.

[ra.ra]

That solid wood face frame does have an edge dimension thinner than 'normal', but it looks great nonetheless - - perhaps it has a different type of rabbet or dado joint where it connects to the side panels. For many of my projects, I very often simply re-use the original stuffing (yep, even with the mineral wool), but in your case with such curious voids inside the cabinets, my temptation would be to scrap the original fluff and replace with all new fiberglass, after ascertaining the correct quantity.  

[DavidDru]

Great!  Congrats.  Have fun.

Did you spy the date stamp on the inside side wall?

My bet is that the insulation just all collapsed over time per gravity into the woofer zone some how.

[stan461]

Nice looking AR3's. I've seen "rough"  and, unless I'm missing something, these don't qualify.
Good luck with the project.

Pots probably need cleaning.
Do all the drivers all work?

Quoting member GD70 (Glenn) from another thread.
"Next I use a very thin viscosity epoxy called ZPoxy, which will be absorbed by the MDF making it solid again."
Perhaps this is the key to filling in the void(s), and at the same time, strengthening the faceboard.

Since you are the first one to open these up,
the logical thing to do would be to replace the caps with the original values.

Lots of varying opinions here on stuffing.
If you are sure you're never going back in, then just distribute
the original stuffing evenly throughout the cabinet.
Otherwise, I'd use acousta-stuf.
Could never hear the difference and don't care to deal with fiberglass.

Take your time and enjoy the journey.
Haste makes waste.

 

[lakecat]

No timer stamp but this figure (in pic) is stamped on all sides inside the cabinet. What I noticed too as I took pics is that there is walnut veneer on the inside also.....some expensive plywood for sure.  Got the Solen caps in and pots are cleaned in one cabinet. Got to get over to hardware store tomorrow and get duct seal and some screws. Will do other one tomorrow....then on to refinish cabs. I didn't mean rough as much as cabs will take some work to get nice. One top has a swollen area where a plant must have sat.

 

 

[lakecat]

I got one done with the caps....pots....and fixing the tweeter...and stuffing back in...new duct seal on woofer....and the good news....it plays very nice!...:) 

Now.....I am taking other speaker apart and this time got some pics of the stuffing as it also is just centered around the woofer. It couldn't have fallen the way they have the sizes of the stuffing put in there. It is intentionally stacked around the area for the woofer. The pieces are as high as side of cabinet and put in a funnel fashion. And just like the other speaker, there is nothing in the upper section of cabinet. Must have been a reason and regret now...putting the stuffing in other speaker in upper section and spreading it out.

This and the thin front frame are questions I wish I had answers to.

[ar_pro]

Out of curiosity, Lakecat, have you measured these cabinets?

The AR-3 factory spec is 11 3/8" deep.

[genek]

22 hours ago, lakecat said:

No timer stamp but this figure (in pic) is stamped on all sides inside the cabinet. What I noticed too as I took pics is that there is walnut veneer on the inside also.....some expensive plywood for sure.  

Cabinet grade plywood is usually faced on both sides. It comes in two varieties G1S (one side good, the other of lesser quality) and G2S (two sides good).

Panel and counter grade plywood is faced one side. But it isn't all that much cheaper than G1S cabinet grade, and most cabinetmakers wouldn't bother to stock it.

 

[ra.ra]

On the thin solid wood face frames, I suspect this was possibly an early variant for AR cabinets since it also shows up plainly on this set of blonde AR-1's currently available in the "marketplace". Nothing to worry about - - maybe even a point of pride . 

The ink stamp inside your cab looks suspiciously similar to the chief inspector who has shown up in a few of my early-to-mid '60's AR cabinets - - he is good luck - - he watches over the crossover assembly. 

Agreed with genek about the panel veneer - - sometimes on the inside of cabinets I have seen a single panel with both faced and unfaced surfaces jointed together that will correspond with a change of grain pattern on the exterior surface.

The distribution of stuffing? Perplexing..... 

[lakecat]

4 hours ago, ar_pro said:

Out of curiosity, Lakecat, have you measured these cabinets?

The AR-3 factory spec is 11 3/8" deep.

It is exactly 11 1/2" deep and exactly 14" wide

[lakecat]

1 minute ago, lakecat said:

It is exactly 11 1/2" deep and exactly 14" wide

And I measured my other pair of 3's and you are correct....11 3/8" deep

[lakecat]

2 hours ago, ra.ra said:

On the thin solid wood face frames, I suspect this was possibly an early variant for AR cabinets since it also shows up plainly on this set of blonde AR-1's currently available in the "marketplace". Nothing to worry about - - maybe even a point of pride . 

The ink stamp inside your cab looks suspiciously similar to the chief inspector who has shown up in a few of my early-to-mid '60's AR cabinets - - he is good luck - - he watches over the crossover assembly. 

Agreed with genek about the panel veneer - - sometimes on the inside of cabinets I have seen a single panel with both faced and unfaced surfaces jointed together that will correspond with a change of grain pattern on the exterior surface.

The distribution of stuffing? Perplexing..... 

My face fronts are thinner than those and these serial numbers put these in middle 60's. Doesn't bother me but I have never seen this before so question why this had that...and that dang stuffing in there like that. I got the other done and have been testing them. I am so relieved that everything works as it should. I adjusted pots at one watt of playing and these speakers sound incredible. Amazing....at 50 yrs of age.