DIY LA4 rack kit

I bought a second silverface Urei LA4 and wanting to rack them together, but also balking at the 85 dollar price tag of the rack ear/connector kit from Studio Electronics, decided to try and make my own using materials you could find at Menards (because I’m in the midwest, and I love to save big money).

I discovered many things on my journey, and thought I’d share them, in case you found yourself in the same situation. The short version? Yes, I did it for twenty bucks, but I’d actually recommend just buying the $85 kit linked above. The long version? I learned a lot about tolerances. You can measure the distance between holes on your LA4 as many times as you like, but by the time that measurement is pencilled onto the metal, punched and drilled, it probably won’t line up. You will need the following pieces of metal: a 1″ aluminium right angle for the rack ears (SKU#2279907), a 3/4″ aluminium flat (SKU#2279842) for the ear spacers, and a 22 gauge piece of 6″ steel sheet (SKU#2284109) for the connector pieces. (Menards doesn’t sell 2″ aluminium flat in 1/16″ thickness, and a 1/8″ piece will make the pair too tall for a 2u slot, so the 6″ plate is way wider than it needs to be, but it doesn’t get in the way of anything.)

You will also need a drill press, a hacksaw and a vice, a center punch, various drill bits, and a 1/4″ flat file, which I didn’t have, so I just used my Dremel. The hardest thing to do is make the oblong shaped hole on the rack ears. Obviously you just drill two holes and file down what’s left in between, but good luck drilling those holes (3/16″ apart) on the same plain. Mine ended up looking kind of drunk, as did the clearance holes in the spacers, and all of the holes on the connector pieces to be fair, but once it’s racked you can’t see any of it! Inconsistencies in how the Urei faceplate is attached to the chassis didn’t help matters, especially with my distant serials. I initially entertained the idea of using the excess material to make more kits and turn a profit on ebay, but quickly disabused myself of that notion. No one would pay money for the product I created. But it works, and while I was scrabbling around in there, I learned how to change the VU lamp. Watch it shine!