Why didn't anyone tell me wiring patchbays is such a pain in the...

GroupDIY Audio Forum

Help Support GroupDIY Audio Forum:

This site may earn a commission from merchant affiliate links, including eBay, Amazon, and others.

Kingston

Well-known member
Joined
Nov 1, 2005
Messages
3,716
Location
Helsinki, Finland
Aih!  :mad:

This is the worst chore I've had to endure for years. I decided I needed a 48-point B-gauge patchbay and now I'm making looms and looms of XLR and TRS cables to and forth the studio. I didn't even make a dent and I spent the whole damn day!

I'm not sure the way I've soldered the cables to the jacks is a solid one either. There doesn't seem to be any physical support for the cables at the jacks, apart from a single bar from one end of the rack to the other. Zip ties seem to work as it's gonna stay as a solid installation, hopefully never needing repairs.

Using star quad for the cable turned out to be a stupid choice as well. It's nearly double the work. Or maybe I need better tools. Some oughta invent some kind of insta-unbraid. Unbraiding this very heavy duty star quad is the worst part of it all.

Share your patchbay and cable war stories.
 
Hope you're not putting mics on B-gauge. The way they connect can do bad things to phantom power supplies, it shorts them to ground, some supplies put up with this better than others.

Mics on jacks of any sort (A gauge, B gauge or indeed Bantam) is a bit silly in my book for this reason.

Assuming you aren't using jacks for mics, that then implies you're using quad cable for line level signals. In my opinion this is silly also. I don't think the extra pair makes enough of a difference at line level to be worth the extra expense.

Furthermore, digital audio just won't work on quad. It's an impedance thing.

Just my two pence worth.

C

PS The bar you speak of is usually pretty good for breaking out multi-pair cable onto B-gauge, just strip about a meter of outer insulation off, zip-tie the whole lot for about 10cms along the bar, then start terminating individual pairs onto your jacks, cutting them to length and tieing them in as you go. I've seen old BBC installations with this type of wiring work and it is absolutely astonishing how neat it can be!
 
Using star quad for the cable turned out to be a stupid choice as well. It's nearly double the work. Or maybe I need better tools. Some oughta invent some kind of insta-unbraid. Unbraiding this very heavy duty star quad is the worst part of it all.

I personally don't think Starquad is a stupid choice! Ok it's a bit more work (not so much once you're used to them) but soundwise I really prefer them versus 'normal' ones.

I tested them on mic and line level signal and prefered the SQ on Mogami product line( and Canare too) soundwise: seems broader frequency spectrum: more bass end more high end... more of everythings in fact! :D .

Unbraiding complicated... sounds like Canare!  ;D
Last time i had to work with SQ Canare multipairs i ended 'cuting' the shield in half with scalpel... I gained some time. I really prefer Mogami SQ for that unbraid is so easy...but afaik don't exist in multipairs... :'(

48 points patch bay... Bantam is much higher price but you don't have to deal with TRS (which i found really a pain in the a.. to build versus XLR) and much more solid connections, and you won't have the problems CollinS mentionned. They will stay for a life too, and are easier to maintain if problems occurs... but it's costly...really costly at first sight.

Tools you can not live without for this kind of task: Weller ws81 (so quick on soldering!),an automatic hand wire stripper, a 'third arm'/ bench vice like the 'mini vise' from Panavise (with a head rotating 360°) , and a good bent narrow nose plier like CK or Facom.  


Furthermore, digital audio just won't work on quad. It's an impedance thing.

Standard analogue cable won't too without modifying the digital signal. You need 75ohms for spdif or 110ohms for AES/EBU. I've once seen an 'old' Mogami cable which was able to pass digital and analogue: it was clearly labelled for that ('high precision analogue/digital cable' iirw) otherwise never seen others like that.
 
that's why wiring guys make a lot of money. to do that tedious most people don't have time or patience for.

all professional consoles with TT or 1/4" patchbays have the mic lines from the live room show up through a full normal patchpoint  into the mic pre on the console. Yes it's not the best option as you can short 48V to ground when plugging in but that is only if Phantom is on. There are other solutions but that to me is more flexable then an XLR panel or whatever.  you could just not use phantom from the board like the boys at sear sound, and use a phantom power box when you need phantom. or better patch your patchbay stuff before you plug a mic in

Now the bar behind the patchbay is strain relief for your wiring.  follow this photo and you can't go wrong. This was wired by keef and it is a work of art.

Patchrear1.jpg


as for wiring.... I am on a cable and patchbay grind at the moment for a client in the process of building a new studio. There are some tricks and tips I have learned to make the job go quickly...

1. find a comfortable position you can be at for a long time. I usually will have  my seat on the lower position and the bench higher up then usual. This allows me to sit straight up. bend over looking down all the time and you get sore quickly. plus it's making cables so I don't need to stare down into a piece of gear.

2. find a great radio station to listen to as you work. Keeps you going on those long nights making cable I highly suggest the internet stream of triple J. www.abc.net.au/tripleJ/listen

3.prepare things in advance. Have things like heat shrink pre-cut that way you can grab or go. I have plastic box much like a fishing tackle box with different bins in it. When shop time is low I can cut heat shrink. Then I am ready to go when time comes.

4. do cables in steps. The worst you can do is strip wire, then tin, the feed cable through the whole of a connector then asseble,etc,etc.  so For example. strip wires all wires in a loom before you move on. this is more like an assembly line and work moves much faster.

that's pretty much all I can think of other then have a well ventilated place to work in. We had our air go out earlier in the week and buy making cables when it's 87 degrees Fahrenheit/ about 30 degrees Celcius in your shop is no fun.

to be honest I have more trouble with doing patchbay labels then I do the wiring part.
 
This was wired by keef and it is a work of art.

:eek: Yes it is! Real clean layout! 8)

...4300 solder points approximately! What is this patch for? Remote patch bay of a 96 chanel desk and whole studio? Really impressive!
 
pucho812 said:
4. do cables in steps. The worst you can do is strip wire, then tin, the feed cable through the whole of a connector then asseble,etc,etc.  so For example. strip wires all wires in a loom before you move on. this is more like an assembly line and work moves much faster.

I had a guy rebel when I told him that, exclaiming "I am a man, not a machine!".  Too bad I really needed machines; he and the color blind guy had to go  :)

The lashing to the strain relief bar is more effective if the wires cross the length of the bar. The wire going to jack 1 enters from the jack 48 end, and vice versa. Run one bundle on top of the bar and the other below it.

Another easy time saver is to make jig out of plywood or even cardboard.  Drill or poke some holes in at the jack spacing, make a few more holes where you can place a releasable tie, mark the other side of the jig with a line to cut off the wires at, and another to mark the outer jacket for stripping.  Just stick the wires through the holes with enough length to get to the cut mark and tighten the releasable tie, then flip it over and bend each wire over tight to the board and mark the strip line on each, then come back and cut. You can use lacing twine on the loom if you want to save the cost and bulk of cable ties.

You can save the marking step above if you place a mark on your wire strippers or find an existing reference point on them to measure against. If you have a tool in your hand then make it do as many things for you as possible.

When soldering, manipulate the conductor such that it wants to fall onto the terminal naturally, otherwise it tends to fray or have the jacket peel when heated. If everything is tinned and well positioned then it will only require a quick touch of the iron to tack down.  Play with the temperature setting of your iron until you have it workable, and think about how much thermal mass the terminal has vs the conductor, placing your iron accordingly.  Keep the tip clean and shiny, and just wet it slightly before you tack the wire.

When working with braided shielding people often forget that they can strip the jacket longer than needed for the final prep length.  It can be useful to do this and then push the braid so that it bunches up, and pick open a small hole at the base of the braid which allows you to fish the conductors out.  You can then snip the braid of and trim the conductors to their final length.

If you get ends terminated in 5 min. ea. then you are doing OK.  If you get really good, it'll be closer to 2 min.  :eek:
 
Kingston said:
Using star quad for the cable turned out to be a stupid choice as well. It's nearly double the work. Or maybe I need better tools. Some oughta invent some kind of insta-unbraid. Unbraiding this very heavy duty star quad is the worst part of it all.


Starquad ... braid? This is why foil screen was invented. It's designed for intensive installation work, the foil comes off with the outer jacket. Do you have some reason for needing to use braid?

 
I've always found the monotony of patchbays quite relaxing... Like the man said find a decent radio station or a calming cd.

We've always had mic lines on bantam bays and have never blown anything from accidental shorting of phantom power.

For mic lines buy the best quality you can, Moses and Mitchel would be my choice. Check VDC Tradings ebay store for good deals on new ones or i've used second hand M&M in a few budget studios. After a clean they have been like new anyway, sometimes they'll come with multi-core still attached and soldered for you!
 
Yeah, I feel your pain...I just did two 96 point bays for myself...with a whole whack of normalled and half-normalled points. No fun at all, but very satisfying when the last wire is soldered.
 
    . . . . . or you could just NEVER plug in a mic with Phantom switched! . . . I worked at a studio that had a panel of switches above the mic ties on the patchbay, switching phantom power directly to the mic tieline. A very good idea if you ask me, especially since there were a lot of esoteric relic tube and ss pres with no phantom available.


  Kindest regards,


      ANdyP


   
 
Great tips everyone.

By the second stereo pair I had already found out I need an assembly line mind set. Now I'm working in big batches and it saves time tremendously. That keef patchbay picture is inspiring.

I chose to ignore normalling because this is a patchbay where connections are constantly on the move. I could not think of any default connections that would make sense on this one. For larger scale mixer/tape/AD/DA the situation would be different of course.

About the phantom power in patchbays issue, I'm fully aware of my choices with this. I have fried my share of AD/DA/etc inputs with careless patching. I know I should keep preamp inputs out of the patchbay, but I want to use all of my preamps as distortion/color/etc alongside the rest of the gear and for convenience reasons I don't want anything else but b-gauge cable on the front side. XLR connector takes so much space as well. Glad to hear I'm not alone with this.

And hey, that's why there's a switch for phantom on/off. If there isn't, it's probably because the chinese wanted to save money where they shouldn't. I know there are mixers with a single phantom switch for all channels and I think it's one of most irresponsible design decisions one can make.

My use of braided star quad is a money saving thing. I needed a lot of quality cable for every audio use imaginable in the studio and simply did not want to waste money ordering smaller batches of misc. cables. I selected Canare L-4E6S which is a time tested heavy duty multipurpose cable. Totally overkill for patchbays, yes. And the braids are probably the best in the business and basically refuse to budge even with heavy tooling.

Last batch of eight starting now...
 
kml23956 said:
So if I follow Puncho, it's xlr connections or risk shorting phantom power.  48 xlr connections.  That sucks.

NO if you follow what I said it was

go with tt or 1/4's from the mic lines in the live room to the mic pre's on the console with a full normal between the 2 patch rows.  It's a standard and I have never had a problem that way.
Just turn phantom off before you patch. That's a given but some consoles don't allow for that so just do the patchbay first before you plug mic's in

XLR patchbay's  IMO are difficult as you can not put a normal, half or full, between 2 xlr patch point, unless someone knows something I don't
 
Just ordered a length of this:

http://www.gepco.com/products/proav_cable/analog_audio/singdual_24_M.htm
singdual_24.jpg


It's my favorite. I first got some dumpster diving when a studio in town was torn down. Used it ever since.

On the other running topic, I've experienced the awkwardness of P48 through a TT bay, on a Neotek Series III with phantom permanently ON.

It sucks to have to walk back to the control room and break the tie line normal before plugging something back in the live room. Especially when combo XLR/TRS jacks were used for line ins and/or returns to the live room.
 
Back
Top