Best way to convert adjustable shelves?

I have an old vertical LP cabinet made from solid maple with 1-3/8" thick shelves, top, bottom, and sides. The shelves are 21" x 16" so they're perfect for my components.

Problem: The shelves are adjustable! My first thought was to use heavy metal L-brackets but maybe there's a better method sonically. Any thoughts?

What type of mounting system holds the shelves?

I ask because my components are all on adjustable shelves using KV brackets and 2.5" maple butcher block shelves.
The cabinet uses recessed and flush metal runners that accept 10-24 machine screws creating the bracket. The screws are fitted with a tubular sleeve to create a straight surface. From the weight of the LPs, some of the screws have become bent, so I can't imagine using this system for components.

Thanks for the reply.
Thought about Dowles yet?

If you can keep the adj shelf stable enough to drill a small pilot hole straight thru the cabinet into the shelf so all aligns properly, I'd say go that way.

some wood caps can be inserted into the recess you'll allow for in the cabinets wall by sinking the dowle in so it's not quite up to being flush with the cabinets side or back walls. then just push in some mushroom buttons into the holes where you used dowles!

Simple... well almost... but surely not beyond being a reasonable solution.
Thanks Blindjim, that's a great and simple solution.

That's how the top and bottom of the cabinet are least it appears to be dowles but could be screws under dowle caps.

My only reservation is that the shelves are slightly undersized (width), so there is a small gap (3/16") between the sides of the shelves and the sides of the cabinet. Also, there is no back.
Screws? So?

That's just another way to go and/or look.

you can get screws with 'shoulders' or sleeves on them too.

there's all sorts of ways to do this... don't get to "paralysis by analysis", with it.

Maybe use shiny metal dowles. perhaps you could take a look around and seek out some solid metal dowles and add onto them some compliant sleeve to aid damping of resonances or vibrations too.

however I'd go with as strongly afixed as is possible... and without a back, and if no piece is to be added there as an additional brace, two per side.

I'd also use a drill guide to insure alignment and equal depths.

Start small with a pilot hole and then move up, to avoid splitting anything. if hard wood dowles can be found or turned down for you, I'd also choose them over the standard ones... but they would do as well actually.

just make the holes a hair larger than the dowles or pins for the adhesive to get inthere.
Good stuff..thanks Blindjim!
You are welcome.

I was thinking too, if the side walls of the rack aren't thick, you might wanna think about adding a strip of wood into that area to bolster the support. Merely ripping some or having them ripped and using a very good wod glue ought to suffice. A rear cross memeber too is a thought if you follow that path, although I'd make that piece thicker of course, but still flush to the racks walls.

Good luck
The sides are just as thick...1-3/8." The dowle or screw method should work. The bottom is already dowled and sits flat on the floor. There is a leveling issue there with the wood floor so I may have to figure out a way to deal with the cabinet doesn't rock, is level, and does not damage the floor.
The shelves are 21" x 16" so they're perfect for my components.

So your inside cabinet width is roughly 21.375 inches. How much width do you require? You can either laminate .05" or .75" plywood to each inside cabinet wall, allowing for a precise dado for each shelf. Using .05” plywood will leave you a rough width of 20.075'; using .075” plywood will leave you roughly 19.875".

You can purchase birch plywood (which nicely accepts stain and can be matched very closely to maple), the width of which should be ripped to the same spec as the inside depth of the cabinet walls -the length of which should be cut to approximately the same spec as the inside height of the cabinet. Now, figure shelving positions and mark the inside of the cabinet (precisely). Then cut your pre-ripped plywood to the necessary lengths to fit above and below each shelve (leaving some room for the glue/cement). Use quality wood glue and screws to secure the plywood to the inside cabinet walls. Drill/countersink screw holes in the plywood so that you secure the screws from the inside of the cabinet (which can be covered with dowels – best, or with wood putty – won’t look professional). Insert your shelves by sliding them in place via the rear of the open cabinet. I recommend using an acoustically designed speaker cement or silicone to “glue” the shelves in place.
2chnlben - Those are great suggestions! Virtually eliminates any weight bearing concerns and maximizes the wood coupling for the entire cabinet...looks good too. Thanks.