How do I remove crossovers from AR-90 without breaking something?

[Kuja]

Hi,

My "new" AR-90 speakers just arrived.

They were sitting unused in some cellar for last 15 years.

All the surrounds are rotted and the drivers are on their way to be refoamed.

I also want to replace all the capacitors.

The crossovers seem to be both stapled and glued.

What is the best and safest method to remove them?

Right now I cant't figure out how much force is needed to pry them out.

I'm affraid that I might break something.

What tools should I use?

Details are welcome!

Thanks in advance,

Aleksandar

[ar_pro]

The glue and staples make it very difficult to remove the crossovers without damaging the mounting boards.

There's also limited space to work inside the cabinet, so fitting a pry tool in is also tough.

The vertical board (with the amplifier connections) can be removed by *carefully* striking it from the outside, around the perimeter with a wood block & hammer - this will dislodge the glue, and allow you to fit a tool under the edge on the inside, to loosen the staples. It's very likely that the flimsy board will crack or chip, though.

The bottom board is tough - without being able to access it from the outside of the cabinet, there's no way to break the glue's hold, as possible with the vertical board. All you can do is dig around the edges, and hope to start to lift it away from the cabinet.

If I absolutely had to remove the AR-90's crossover boards, I'd be committed to saving the components, and breaking the mounting boards, and replacing them with more robust panels.

[r_laski]

Aleksandar,

If you are only removing the capacitors and replacing them with capacitors of similar size I recommend you carefully desolder the leads from what they are connected to and then pry out just the capacitors with a short screwdriver, putty knife, or mini pry bar -- about 4 inches long. I've removed many crossover components from AR speakers and usually the hot glue will break free from the board without taking too much of the board with it. You may (probably will) have to carefully remove the resistor board using the same tools to get at some of the capacitor leads.

If you are going to use bigger (polypropylene) capacitors to replace the electrolytic caps, you may have to reposition other components on the crossover boards to get everything to fit. When I recapped a pair of AR-90s I found it easier to remove all the components from the both boards without removing the boards. I build new boards on masonite pegboard and glued these new board to the old boards inside the cabinet. The key on the vertical board is to line up holes you make for the binding posts with the binding post holes in the original crossover board that you left in the cabinet.

Hope this helps

Rich

[ar_pro]

There's an AR-90 crossover on ebay right now, that looks to be in pretty decent shape.

[rrcrain]

For the most part, the crossovers are held in place with a small amout of glue and a few anemic staples. if you're reasonably careful, the old boards can be safely removed with minimal. I successfully removed the main (back) board and recycled it and I rebuilt the bass crossover in place.

Richard