Over the years, I've been around the block once or twice with location work running a remote truck and apparently well enough to get a TEC award nomination or two. It had a 54 input splitter, 3 way out, Jensen transformers and ground lifts on the split legs. Multipin connectors were the big AMP locking blocks with the lever action, 100', 200' and 250' snakes.
Here are some pictures of my current splitter, a 32 input 2 way split that can be expanded in number of inputs and another leg added for a 3rd output if desired.
Omigosh, it's the dreaded Radial splitter with DB25s, this can't be professional !!!!
Actually it is. 4 units mounted in a 10U SKB crate with 10' and 25' tails on the outputs. It's really quite simple; all you have to do is provide for stress relief so there is no strain put on the connectors and leave them in place permanently. The zip tie mounts are doubled up with permanent adhesive and if that's not enough for you, they are center tapped and can be bolted into place such that ripping them out of the wall of the case would be required to do damage. This tweak is under $10 in parts and takes 30 minutes of your time.
Anyway, just wanted to show that there are professional ways of doing things even if it's not the old skool techniques we are all familiar with.
Well, to me that's just an example of the fact that professional people
sometimes adapt less than professional quality gear
to their purposes. It certainly can be done. When I was a tech for FM Productions (Bill Graham) back in the day we had racks of Phase Linear 700s that had been heavily modified, partly to prevent the weight of the transformer in the back front tearing the flimsy aluminum rack ears off the chassis when they were roaded.
I believe I did mention that you CAN use gear with DB25s as long as the cables are strain reliefed and are short runs to panel mounted professional quality multipins - this isn't that far from that. I personally dislike splitters with hard wrired pigtails most of the time* (Probably an old person's prejudice), bnut if your strain relief is adequate there shouldn't be a problem unless the SKB case happes to crack at the screw holes, which would not be totally unheard of.. If the strain reliefs are only secured by sticky foam I don't know if I'd trust that - I've seen them pull loose.
I dunno - as a service tech I was trained to look for potential failure points and to not assume that conditions would always be optimum.
It's just the Rack rail spacing standard for 1U, 2U, 3U, etc. I think it's an IEEE spec.
An easy way around it is to build the rack rails from wood and then you can space it however you desire. Wood also gives you ground isolation from unit to unit unlike metal rails. We built amp racks doing this and it works very well, especially for big heavy amps. We put in front and rear rails. This was for some QSC 3500 and Crown DC300 amps back in the '80s and it also held a couple of racks of Adams-Smith 2600 synchronizers, audio/video DA's and black burst/sync generator. There are tapped metal fittings that get hammered into the holes in the wood rails for threading the bolts in. Make certain your bolts are properly sized and the wood rails heavily secured to the frame of the rack. Heavy Duty casters are recommended. Any decent carpenter can build this with basic tools. Wood looks good too.
I agree totally on the wood rails - at FM all our cases were made in the carpentry/set design shop and were built like tanks - and wood rails go a long way toward eliminating ground loops. We had lots of DC300s, modified Phase Linears, and,(IIRC) BGW 750s. We also used wood rails for our outboard racks for the isolation.
The spacing on the splitter rack was a concious decision to make a little more working space on the front and back. This rack doesn't see incredibly hard duty in transit so the pairs of bolts are enough to hold things. It's not getting loaded into semi's by Teamsters/IATSE roadies. If/when it gets expanded, things will be rearranged to a tighter spacing and fully secured with 4 bolts per unit. I don't consider the SKB cases hard duty by any stretch, certainly not in the Anvil ATA class like some other cases around here, but for my purposes it's fine and they aren't heavy like the Anvils are. My UPS is in an Anvil 2U and you know it when you pick it up. The SKB stacking form does make it easy to mount different units on top of each other, ie, remote controlled preamp/distro rack on top of the splitter.
To me, the tight spacing is just another indication that the splitters are not designed toi be professional (road) quality. They're designed to be installed and not moved. And no, I don't regard the SKB cases as being road quality, either. Or course they are one heck of a lot lighter and cheaper, and they do stack nicely.
As far as the "not retting loaded into semis by Teamsters and IATSE stage crews", haven't you ever worked in a city (like Cleveland, IIRC) where they WILL NOT let you move your own cases under penalty of hefty fines? They just don't give you the option in some places. (At least not unless the unions have changed drastically in recent years...)