Audio / Stereo Rack

@pindac ​​​​@muaythai The fastening is done via short sections of 8mm threaded rod. Each vertical tube has 1/8” thick metal disk welded about a 1/2” from the end of each tube threaded to receive the threaded rod. The rods are prepared so they can screw in only so far. The assembly starts from the top with 8mm through bolts that feature a broad mushroom head that rises 1/8” above the surface of the top shelf and terminates upper portion of the assembly. The bottom terminates in “points” that can couple the stand to the floor through carpet; or, by use of dimpled disks about the size of a U.S. $0.05 ‘nickel,’ prevent it from damaging wood or vinyl flooring. Each leg’s length can be adjusted up to an inch or so, and a locking nut is provided. I recommend starting with each leg at its shortest and adjusting by extension, monitor what is happening while you turn the screw so as not to ‘adjust’ the height of the shelf above, not the leg beneath (don’t ask how I know this).

For the curious Do-It-Youselfers: The thread pitch of the rod is not standard, but it closely approximates 5/16”-18. I exploited this fact to add two shelves from a standard audio rack to my previously purchased amp stands. By drilling one hole and employing a single 5/16”-18 bolt I was able to secure the two shelves to the amp stand and thus terminate the lower assembly near, but not on, a leg ‘footer’ (the amp stand is about two inches deeper than a standard rack).
Employing the same trick with 3” sections of 5/16”-18 all-thread, and standard 3/4” PVC pipe couplings (which fit snugly inside the tube sections) I managed to extend 10” leg sections to 13 inches. Spray painted flat black before assembly, the couplings are virtually indistinguishable from a few feet away, and quite unobjectionable up close. I also used 5/16” x 1-1/4” boat washers to provide one of the benefits of the X-braces: the washers keep the tubes from eating into the particle board shelves. By this means I got the clearance I needed for my tallish 95 lb. McIntosh amplifiers. I wish I had painted the edges of the washers before assembly, but it’s likely a detail that only I will notice. I’m not putting anything on the upper shelves that weighs over thirty lbs., so I think I’ll be OK. I only purchased the two amp stands and one standard 4-shelf audio rack, and (4) 10” ‘legs’ (plus the 5/16”-18 rod and 3/4” PVC pipe couplings), and I have parts left over after creating two, one-of-a-kind three-shelf racks. Again, not heirloom quality, but gets the job done, and looks nice. And everything was done in a day after receiving the shipment which only took about two days —a week all in. 

@oldrooney There certainly looks to be room to tweak this system to meet a few bespoke requirements.

The 8mm Thread referred to might be a common Metric Thread Pitch for a 8mm Thread, so not Whitworth / UNC. 

Speedy Supply and  simplicity to put together are seemingly what the OP has requested as a recommendation, as they are quite delayed in their earlier made plans.

@pindac I checked the pitch at Lowe’s, and versus 5/16”-18 and it matched neither. I think I recall the pitch on the 8mm thread as being 1mm, where I figure you would need to special order a coarser thread at 8x1.5mm. A 5/16”-18 would start to thread into one of the 8mm locknuts, but could not be threaded completely through: it would jam just as it got flush with the back side.
However, it was another story with the 1/8” thick disk welded inside the leg tubes, there weren’t really enough threads on the disk to interfere, it wasn’t hard at all to force it through the first time, and then it pretty much spun free. The assembly only calls for hand tightening, and I applied all the torque of which I am capable without incident.

Looks like a great choice.  Congratulations….