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Patchbay jack problems??

Discussion in 'Sound, Music, and Intercom' started by jkowtko, May 15, 2009.

  1. jkowtko

    jkowtko Active Member

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    Should patchbays have connection problems with their patch jacks?

    The high school just completed their $$$ new perf arts center with lots of sound equipment. In the rack are four 2U TRS patchbays, maybe 24in/24out each, with full jack normaling.

    People have complained that the jacks don't work very well, that you have to jimmy the TRS jacks around, maybe pull them out a bit, to get the connection. My only experience with this equipment has been a few hours a night since Monday, and I've noticed some connection problems as well.

    I won't be at the school until tonight, but won't be able to read forum email there either, so I have to post now lacking some info on the particular unit. Just wondering if anyone has an idea of what's going on?

    Behind the rack the wires look to be wrapped and routed very professionally, with twist/screw fasteners on the back side.

    Sorry, I don't remember the brand/model offhand.

    Should any patchbay product have trouble with connections? After all, that's the sole purpose of the product. Or do I just need to hit it with some deoxit and work the jacks a bit?

    Thanks. John
     
  2. avkid

    avkid Not a New User Fight Leukemia

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    A brand new patchbay should have very tight jacks, no wiggling necessary.

    It sounds like someone cheaped out in a bad place.

    If it was just installed the contractor needs to answer for their botch job.
     
  3. Footer

    Footer Senior Team Senior Team Premium Member

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    I am going to say you have the wrong 1/4" Cables. It is possible the patch bay was designed for military style 1/4" connectors as most patch bays are. If so, a standard 1/4" connector will not work in these type of jacks.

    [​IMG]
     
  4. jkowtko

    jkowtko Active Member

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    We do have a few dozen of the special green patch cables. And yes, you're right, those do look a bit more like #4 or #6 in your photo, vs. a traditional TRS. However I have had both the special patch cables and standard TRS both working.

    Would a cheapo patch bay really have connection problems? But, based on the purchase of other equipment, these guys didn't skimp -- all is mid to high end equipment across the board. Unless someone grabbed four used surplus ones from somewhere, I'm guessing these are all new product as of Feb '09

    Hmmm ...
     
  5. avkid

    avkid Not a New User Fight Leukemia

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    Close, but not quite.
    Bantam plug patchbays are quite popular in recording studios and broadcast applications.

    [​IMG]
     
  6. jkowtko

    jkowtko Active Member

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    Yep, that looks like it.
     
  7. epimetheus

    epimetheus Well-Known Member

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    Aren't the Bantam shafts smaller in diameter compared to a standard 1/4" TRS? Maybe you've got Bantam cables in a standard 1/4" patchbay? Or am I just off my rocker?
     
  8. jkowtko

    jkowtko Active Member

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    They both seemed to have the same amount of resistance, and neither one appeared to have much play. The Dept head (non-technical) said you sometimes need to pull the jacks out a bit to get them to connect.

    I just got the show director to call me with the info on the patchbay:

    http://www.bittree.com/catalog/detail1.cfm?pageID=972

    It's Bittree, either the 481 or 489 series (I didn't see the programmable option until just now), 2x24 configuration with punch panel in the rear. I can't find anything for sale but it looks like this brand isn't low end -- is it?

    Thanks. John
     
    Last edited: May 15, 2009
  9. avkid

    avkid Not a New User Fight Leukemia

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    Absolutely Bantam and most certainly not cheap.
    I found their products from $300 to just under $2000.
     
  10. jkowtko

    jkowtko Active Member

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    Okay, I had a fair amount of time to look over the equipment again last night --

    Looks like the "tip" part of the Bantam is narrower than standard TRS, causing the TRS to catch a bit when pulling out from the inmost position. So what I don't know is if a normal TRS will "stretch out" the connectors inside, causing bantam connectors that subsequently use that jack to have connection problems.

    In any event, I didn't find a single connection problem last night. I did find a handful of jacks that were mis-wired though ... two TRS, one completely dead and one with a nasty buzz, and four connections from TRS to RCA ... I'm guessing just mis-wired in the back of the patch bay, something I will try my hand at fixing this afternoon, and will patch around if I can't fix it.
     
  11. museav

    museav CBMod CB Mods Departed Member

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    The Bittree 481 and 489 series are 1/4" long frame patchbays, so they are not bantam. Bittree's bantam (TT) bays are the 961, 968 and 969 series. And that is not at all a bad price, you are more in the the ADC and Audio Accessories patchbay quality level and the higher prices are when you get into programmable bays and/or special connections on the rear.

    The comment that you have to move them in or out to get signal to pass tells me you probably don't have the right patch cords. If someone jammed in standard TRS jacks they may have indeed bent some of the internal contacts.

    As far as fixing this, you said "The high school just completed their $$$ new perf arts center with lots of sound equipment." so you should be talking to the Contractor that installed the system. They likely have some form of system warranty and if it didn't work right in the first place they should definitely fix it. On the other hand, if someone did bend the contacts in the patchbays they may not cover that.
     
  12. jkowtko

    jkowtko Active Member

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    Yes, the contractor is going to be called in this summer to shake out the bugs. I was just hoping to find/fix some problems during my show.

    Tonight was the final performance of the dance show. I checked out the patch bay some more -- did find a couple of improperly wired cables from the board to the patch bay, but no flaky jacks. The bantam jacks seem to work much more smoothly than TRS. I'll also guess that some of these jack holes have been potentially damaged by TRS rough-handling.
     
  13. museav

    museav CBMod CB Mods Departed Member

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    If it was a bantam patchbay it would be 2x48 rather than 2x24 and you would not be able to force 1/4" jacks into it, a 1/4" connector would be almost 1-1/2 times the size of a bantam/TT patchbay jack (6.35mm or 0.25" diameter for 1/4" versus 4.4mm or 0.172" diameter for bantam/TT).

    If something does not work, that is not shaking out bugs, it means the installation is not complete. If you start using the system you can create an undesired situation in regards to the installing Contractor fixing anything. It's sort of like court, if the Contractor can show 'reasonable doubt' that the problems may be the result of others rather then the initial installation, then that may release them from responsibility. For example, if you fix any patchbay wiring then you have modified what was installed and thus the installing Contractor can legitimately argue that the installation has been modified by others and there is no longer any way to determine if a problem is the cause of the initial installation or the subsequent use and modification. Change enough things and you give the Contractor a legitimate argument that they can no longer be held responsible for any of the work. So get them out there now before you start using the system or addressing the problems yourself or you may never get them out there.

    1/4" plugs and jacks come in two forms, the common A-gauge used for connecting audio equipment and instruments and the B-gauge typically used for patchbays. An A-gauge plug has a pointed tip that is the full 1/4" diameter and the isolator between the tip and ring in a TRS plug is concave while a B-gauge plug has a rounded tip that is smaller than the diameter of the sleeve (the ring in a TRS plug is also slightly smaller than the sleeve) and the isolator between tip and ring is convex and larger than either the tip or ring. Originally developed for telephone switchboard patching, the B-gauge plugs tends to be more durable, are easier to insert, put less stress on the spring loaded contacts in a patchbay jack and are self cleaning. If you insert a B-gauge plug in an A-gauge jack you will likely get intermittent and/or noisy operation as the spring contacts in the patchbay will not make good contact with the tip and ring. If you insert an A-gauge plug in a B-gauge jack you can irreparably damage or even break the internal spring contacts in the patchbay.

    I don't know what training you received from the Contractor or if they were even contractually obligated to provide any training but if they used B-gauge patchbays then noting that you should only use appropriate patch cables and not standard 1/4" TS or TRS cables probably probably should have been addressed in the training.
     
  14. jkowtko

    jkowtko Active Member

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    Training? Ha! When I showed up for the first time, the house tech had quit a few weeks prior after one month on the job (the story is that she was overwhelmed by the complexity of the system -- evidently she wasn't very technical), so my guess is that training that the AV installer provided went out the window. So my "training" was a few high-level "I think this goes there" comments from the artistic staff and dept mgmt, reading and deciphering the the not-quite-100%-accurate as-built master wiring diagrams, and two binders with docs on every piece of equipment, (except of course for the patchbays :). Fyi, the board is a Tascam DM-4800, which no one there knew how to use ... (their trusted "sound guy" of 30+ years had run the last show on a CR1604 with mono output to one channel on the DM-4800 and out to LR ... no use of Auxes, groups, any digital features of the board, or any of the 10 side and rear fills in the theater.) .. so I had to learn the board from scratch on my own during the week, dealing with improperly set output patches (aux and grp were switched) further complicated by bad cabling from board to patchbay on grp 1 & 2 (which when I got there were aux 1 & 2) ... I think you get the idea ....

    I did make a few calls to the AV installer whose number they gave me during the week. He was helpful to an extent, standoffish and first, but once he realized I was technically capable, offered to come by the school and walk through all of the equipment with me, note and fix problems.

    I agree with the basic contract law and principles. I wouldn't tamper with the equipment installation unless I knew for sure how to fix it, and was willing to take responsibility for fixing whatever I do touch. The school staff already has plans for a different group to come in and do the shake-out (evidently some drama between them and the AV installer, who was different from the AV designer, and also note there was a last-minute board switch which resulted in a mismatch between the board and the patchbay cabling and assignments)

    As for 1/4" jack types, I see what you mean. The Bittree catalog shows the B-type connector in their photo of patch cables for the 489 ... that doesn't preclude the use of type-A jacks in the patchbay, does it?

    Thanks. John
     
    Last edited: May 17, 2009
  15. museav

    museav CBMod CB Mods Departed Member

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    You may be able to find A-gauge patchbays in the MI market (dbx, Samson, Hosa, etc.) but most pro bays (ADC, Audio Accessories, Bittree, Whirlwind, Switchcraft, Neutrik, etc.) are designed for B-gauge patching. You really do have to use the proper patch cords, using a B-gauge patch cord in an A-gauge bay will typically result in very unreliable connections while using A-gauge patch cords in B-gauge bays can permanently damage the bay by bending or even breaking the contacts.

    I do not doubt your capability to fix the problems, my concern was the scenario of the "low bid" Contractor looking for any reason to cut their losses or maximize their profit and not letting that happen at your expense.
     
  16. jkowtko

    jkowtko Active Member

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    I don't think this was a lowbid contractor ... they do seem pretty competent. The wiring organization in the back of the racks is impeccable.

    Thanks for the heads up on the patchbay A/B issue .. I'll let the school know to be careful there.

    Thanks. John
     
  17. RBeast

    RBeast Member

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    Not the contractors fault... Long frame bays are very reliable, but typical TRS 1/4 inch jacks will stretch them and ruin them. I have replaced several for that reason. Hopefully it's just a few jacks to replace.
     

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