help wiring my first TT patchbay

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byoung

Well-known member
Joined
Jul 16, 2006
Messages
125
Location
San Gabriel Valley, CA
So I've undertaken the task of wiring my first TT bay. I am running different combinations of normalled and half normalled. I was told to vertically strap the grounds (A) because I have 16 XLR's(which may require discrete channels of phantom power) which are normalled to the inputs of my mixer, and (B) because it was easiest to do with the 3 conductor cable I'm using.

I will sometimes break that connection to route the XLR's to my outboard mic pres(which may use phantom as well). This has me curious now because when I insert a patch cable it breaks the Tip and Ring connection but the grounds will still be strapped to the jack below. Will this cause problems? Is there a better way?

Also another big question....my TT/Bantam cables(Planet Waves) that I purchased only seem to be connected on the Tip and the Ring yet they have distinct TRS sections......is this normal behaviour for a TT patchcord? I had thought they would conduct just like a 1/4" TRS cable. Will these work for patching a phantom powered mic through the bay?

I have stopped midway through my installation because I was worried I might be doing something wrong, and figured I'd ask.

Thanks,
Brian
 
Patchbay layout and termination details often involve small compromises, and you have discovered one of them. In my opinion, the way you are wiring your bay is best. That is, on the half and full normalled positions, include a ground jumper between the top and bottom jacks. As you observed, this connection will not be broken along with tip and ring when a cord is inserted, but 99.9% of the time, this works perfectly well, withoit causing ground noise or other problems.

As for your patch cords, they most certainly should have the shield connected on both ends. If you have cords that don't, they are probably faulty.
 
planet waves makes TT cords :? In my experience with various pre-made cables, the molded ends tend to the break causing the cable it self to go bad. Put on new ends and you should be o.k. usually. This includes Hosa and the like.
If you really want some solid TT cables by the Mogami pre-made. It's what every studio I have ever been in used and they are rock solid. In fact no matter how hard I have seen people yank on them they never seem to break. :thumb:
 
I bought a used bittree recently and later noticed that the grounds were strapped (I think that's what it's called); that is, there was a 2mm sheet of punched stainless running in between all jacks and the face. I had to unscrew all 52 points to take it out. I then did the same thing...individually soldered in vertical grounds. I think it took two episodes of king of the hill and one malcom in the middle to complete.

I should add, with regard to patchbay wiring, I was surprised to see how many patchbay points I ended up using even for a few pieces of gear in a portable rack. I have more to do yet but I need a break from those bittree E3 connectors...ugh.

David Kulka, nice to see you on this forum. I am very much enjoying the 312s you sold me a few months back :thumb:
 
well it is good to see that I am on the right track wiring then. It is very time consuming....I will say that, but in the end my studio will be wired to perfection ;-)

as for the planet waves cables....yeah I tested all 24 that I bought for shorts(they are all new and I had just pulled them from the packaging before testing). I have found out of 24 there were 9 that didn't have the shield connected or were bad in some other aspect. Now thats some QC. I'm going to see about sending these back even though it's been about a month since I ordered them. When I bought them I figured that they had a lifetime warranty, but now I am thinking that the trouble to replace them when they go bad will be more frequently than I thought and not worth the time.
 
To buss or not to buss. . . I'll ask an easier one: vote dumbocrat or republicant? :wink:
Look at an 80 series Neve and all shields are isolated except for vertical normalling channels. Look at a 4k-9k SSL and the points are mounted on aluminum blocks, with each wired to chassis. In each case there is a heavy piece of metal acting as a "noise sink".
In today's smaller studios it is better to go with the isolated shields. No bussing.
That said, I have been in plenty of small studios where they did buss the shields, and the problems for which I was called were not as a result of any bussed shields.
Clean terminations on quality wire implementing a proper normalling design with attention paid to the powering will probably make the bussing/ not bussing a non-issue.
And do a search for "lifting shields" to really blow your brain!
Mike
 
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