Audio Patch Bay

Edrick

Well-Known Member
Premium Member
I've got a ADC PPA3-14MKIISN Audio Patch Bay.

Without a patch cord it's basically 1 to 1. Port 1 goes to Port 25 for the output. As soon as I connect a patch cord into port one it interrupts the signal rightfully so. However my understanding is I should be able to patch this into another port and re route the signal. However this does not seem to be the case? Perhaps I'm missing something which I obviously am.

I connected a multi-meter to test continuity and if I connect to the Tip terminal on Port 1 and Tip Terminal on Port 25 without a patch cable signal flows. When I plug in to port 1 it interrupts, I've then tried connecting the other end of the patch cable into say port 25 just to test going straight through and also tried connecting to say port 26 to see if I could route audio out of port 26 but nothing. I put the other end of the test lead at the tip of the other end of the patch cable and get nothing there either?

So I'm clearly missing something here?
 
I've got a ADC PPA3-14MKIISN Audio Patch Bay.

Without a patch cord it's basically 1 to 1. Port 1 goes to Port 25 for the output. As soon as I connect a patch cord into port one it interrupts the signal rightfully so. However my understanding is I should be able to patch this into another port and re route the signal. However this does not seem to be the case? Perhaps I'm missing something which I obviously am.

I connected a multi-meter to test continuity and if I connect to the Tip terminal on Port 1 and Tip Terminal on Port 25 without a patch cable signal flows. When I plug in to port 1 it interrupts, I've then tried connecting the other end of the patch cable into say port 25 just to test going straight through and also tried connecting to say port 26 to see if I could route audio out of port 26 but nothing. I put the other end of the test lead at the tip of the other end of the patch cable and get nothing there either?

So I'm clearly missing something here?
Hello! Since no one else has replied to you yet, I hope I'm not insulting your intelligence here by asking something REALLy basic. Are you using a patch cord with the absolutely correct connectors, the real deal manufactured to work with your ADC jacks? I guess what I'm really saying here is, can I safely assume you're not using a cable with 1/4" standard 3 conductor "stereo" connectors of the type routinely supplied on headsets for your home stereo?
Edit to add two more of my dumb questions:
Is your patch bay already racked and wired into an existing system or is your post relating to an 'out of the box' patch bay sitting, unwired, on a bench top?
With apologies if I'm insulting you.
Toodleoo!
Ron Hebbard.
 
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To the best of my knowledge they're the correct patch cords and not just regular TRS cables. They are definitely audio patch cords and look to be correct from what I can find online. This system was given to me second hand and it's on the workbench right now.
 
To the best of my knowledge they're the correct patch cords and not just regular TRS cables. They are definitely audio patch cords and look to be correct from what I can find online. This system was given to me second hand and it's on the workbench right now.
I'm now understanding this to be a raw, 2RU, manufactured patch bay assembly sitting on your bench without any external wiring connected to the external termination points on its rear side. Now that I realize you've yet to install any interconnections (I'm meaning between jacks rather than from or to other devices) on the rear panel, I suspect we're zeroing in on your situation. As it's 1:30 a.m. here, coupled with my stroke imposed near blindness, I'll beg off digging through the specifics of your precise assembly on line and leave you with a few quick thoughts:
As Derek has suggested, understand normalling, full normalling and the differing variations of half normalling. I gather you're seeing five connection points PER JACK extended to the rear panel labelled as Tip, Ring, Tip Normal, Ring Normal and Sleeve per jack. I'll leave you with this for now and please post back with your progress. Know that ADC manufacture QUALITY products and I doubt you'll regret your acquisition. I spec'd and supervised the installation of many of their jack fields, WHEN I COULD SEE, and will gladly offer you any assistance I can.
Toodleoo!
Ron Hebbard.
 
Or, this could be the simple problem that befalls all old, under-used patch panels (yes, including ADC). The jacks get dirty (oxidized) and do not work reliably anymore. If you liberally douse the beast in Caig DeoxIT, and then exercise the jacks by plugging and unplugging a cord into each about a dozen times, it might work for awhile.

With so many better alternatives available now, I avoid installing patch panels at all cost. They are laborious to install and a major pain until the day they get ripped out.
 
Or, this could be the simple problem that befalls all old, under-used patch panels (yes, including ADC). The jacks get dirty (oxidized) and do not work reliably anymore. If you liberally douse the beast in Caig DeoxIT, and then exercise the jacks by plugging and unplugging a cord into each about a dozen times, it might work for awhile.

With so many better alternatives available now, I avoid installing patch panels at all cost. They are laborious to install and a major pain until the day they get ripped out.

What would you recommend over a standard patch bay?
 
Most systems I spec these days only use patchbays to interface the existing analog infrastructure into digital stage boxes for the console, and that's only where they have abundant analog I/O.

The standard lately is digital stage boxes for a digital console, and analog infrastructure XLR fan outs at the console is limited to enough analog I/O you don't have to drag a stage box out every time you need to plug in just a few microphones.

In general, the reason to have analog patchbays moving forward will be for theaters that want lots of 1 or 2-input jacks scattered all over creation in their venue. This is less common on stage and more common on catwalks, loading galleries, backstage areas, and around the house. On stage it's typically stage boxes and/or 8-input panels DSL, DSR, USL, and USR.

If you do go the route of a patchbay, hide all your short 1/4" cables. Fastest way to kill the jacks in a patchbay is trying jacking in 1/4" plugs into a patchbay with military patch points.
 
Or, this could be the simple problem that befalls all old, under-used patch panels (yes, including ADC). The jacks get dirty (oxidized) and do not work reliably anymore. If you liberally douse the beast in Caig DeoxIT, and then exercise the jacks by plugging and unplugging a cord into each about a dozen times, it might work for awhile.

With so many better alternatives available now, I avoid installing patch panels at all cost. They are laborious to install and a major pain until the day they get ripped out.

TL / DR Warning FIRMLY IN PLACE!
Two comments:
1 - Remember the little plug-shaped 'injector / burnishers' with the hole down their axial centre-line leading to a couple of cross-drilled exits at key points? You plugged them in from the front, inserted the tubular nozzle of your favorite pressurized spray cleaner, gave it two quick shots then, while rotating the 'injector / burnisher between your thumb and fingers, simultaneously pulled and pushed it forth and back in a vain attempt to clean / deoxidize the impossible to reach normalling contacts?
(Holy run-on sentence Bat Man!)
And then there were the appreciably smaller 'Bantam Jacks' putting twice the jacks in the same rack space with more than twice the same old problems. Yeah, they made tiny wee 'injector / burnishers' for the Bantams too.

2 - When I was younger, I was far more willing to dive headlong into 'tilting at windmills'.
Fresh from 13 years maintaining a commercial AM station's downtown studios, and their associated patch bays, along with a pair of ancient 1 RU bays in their non-climate controlled / spiderweb and bug infested concrete transmitter building in a grassy, out of town, hill top field where spiders, bugs and patchbays never learned to cohabitate successfully; I left town moving to Stratford to become the 'head of sound' for their main venue.

Stratford was different: When I arrived, I was first introduced to a gentleman from IA 357 who'd, after two phone calls, wanted to at least meet me face to face after managing to drag me there as the only potentially qualified IA member they could commandeer and offer to management who were trying to usher in a youthful, non-IA, home studio owner with zero theatrical experience. First was an office meeting with the Production Manager after which I was paraded to another office and, one at a time, 'sacrificed' to the Director of Music and the Music Administrator (as amongst my duties would be the multi-track recording and editing of originally composed orchestral music). After having met management in offices, I was finally permitted to see the booth. Their main booth was a low-ceilinged / high-floored black cubbyhole roughly 8' x 8'.
Let me touch on ergonomics here: Imagine a space that small where you opened the door outward and immediately 'tippy-toed over a thickmaze of un-labelled cables to reach your seat in the midst of the cable piles. The window to the stage was 90 degrees to your left. The main console (a massive, custom designed and built, Ward Beck, fully balanced, 12 in x 24 out matrix console with nary a mic input in sight and an array of 288, 5/8" square buttons) in front of you. One Tannoy Belvedere monitor on the floor playing into your right thigh. The other, totally different and supposedly stereo, monitor hung high on the wall behind you above the entrance door. A Scully 280 1/2" four track (each channel of electronics occupied 2, full width units of rack space) off your right elbow. A Scully 280 1/4" two track on a shelf above the console along with two unbalanced cassette recoder / players. A home style Revox (with RCA outs) physically balanced precariously atop something to your left and largely obscuring your view of the stage. Toss in an original Studiomaster 8 x 4 submixer, a Charlie Richmond 8 x 2 sub, a small stack of about 5 of the little Shure M63 EQ's, M67 and M68 mic mixers and you'd just met the mic pre's for reinforcing the live, out of sight above the stage, orchestra. Add a 44RU rack housing 13 of Crown's (3RU) D150 dual channel power amps and you had the 26 channels for the Ward Beck's 24 outputs with the remaining 2 channels to power the monitors.
Realize, other than a minimal number of proper patch points housed within the main console, THERE WASN'T ANY SANE MEANS OF PATCHING ANYWHERE IN SIGHT. Other than the Ward Beck's outputs routing over to the amp rack via a single, large, Elco multi-pin; the entire rig was a textbook example of how not to conveniently position, let alone interconnect, gear. It was a total 'lash-up' of temporary cables, adapters ordered in from the local, downtown, 'high-end' audiophool store. Unbalanced gear interfaced to balanced gear in a total mish-mash of home-brew adapters with nary a transformer in sight and they wondered why they were hearing taxi radios when cabs delivered patrons to the front entrance. Honestly!
Prior to the beginning of every performance, the FOH manager assigned two ushers, with rain coats when necessary, to patrol the drop-off lane with flags and flashlights to ward off any taxis delivering late arrivals. They routinely did the same thing if there was ever a need to summon an ambulance during a performance.

How did it come to look like this and WHY?
They did their MAJOR revamp, introducing electronics to their TOTALLY acoustic space in 1970. They'd NEVER had a Head Of Sound position in their IA contracts! They didn't need one when they began in the tent in '53. When they initially built their actual building it was designed as a totally acoustic space; no vocal reinforcement, no orchestral reinforcement. All EFX were 'performed' live by a negotiated cross-blending of IA stage hands, Equity performers and AFofM musicians. Effects ranged from thunder sheets and various sized wind machines all the way down to musicians lightly running dampened fingers around the rims of wine glasses and LARGE metal bowls to create howling noises in the pre-synth days of the early 1950's. (As an aside: Even during my time there beginning in '77, they'd have me add a mic in some back stage corner to reinforce one or two wine glasses being 'played' by whichever cast members weren't on stage at the moment.) Once they'd begun their foray into the brave new world of open reel tape, electronics and amplification; they began with the director of music and the production manager negotiating with the IA to bring in whomever they could 'hornswoggle' into coming aboard for which ever production, or productions, they were planning to use the equipment for in their ROTATING rep'. Few seriously qualified people were willing to relocate to Stratford for as few as two or three performances in any given week whenever their production came up in the rep'. Year after year, season after season, on a per production basis, people arrived, lashed together whatever they could muster, prayed the audience noise would hide the hums 'n hisses, did their penance and moved on out of town. (Where was Derek to advise me against graduating into the 'big time' when I could've used him?) When they sweet-talked me into driving up for an interview, they didn't have a full time sound position in their IA contract. They began by asking how many productions, or which productions, I might be willing to consider whereas I'd presumed I was to be interviewed for, and offered, their full season, if not a full year, position. They eased into negotiations with 'some shows only run the first half of the season and then you could escape. Others only the latter half of the season whereas as still others (Cringe) would run the entire season but, once they were rehearsed and open, you'd have to trek back 'n forth to Stratford for fewer performances per week once the entire season's productions were all up and running in the full rep'. They'd never before had a naive fool like me show up and suggest I was willing to take on the whole shebang from the beginning of rehearsals clear through to the final performance of the season. Thus I began my "seasonal" employment. By the end of the closing performance, as I'd occupied my free moments maintaing and improving their extensive cue-light system. Reworking their four channel Electro Vox intercom system originally conceived by its manufacturer as something created to sit on secretaries' office desks, along with many other little 'ergonomic' improvements as anyone would want in any broadcast control room and / or production studio and or pro' recording studio. At season's end, when the place cleared out to a nigh on vacant space, I asked if they'd mind my keeping me on for one more week to wrap up a few loose ends. In one and two week increments, they kept me on permitting me a two week escape before beginning the next season's prep' week. NO WONDER THEIR BOOTH, AND SYSTEMS, HAD DESCENDED TO SUCH A STATE.
To FINALLY drag this around to patchbays:
Over the course of three or four seasons, KNOWING what a PIA jackfield / patchbays of the days had been during my 13 years in broadcast, I settled on designing, fabricating and installing a totally XLR patch from scratch. This was appreciably before people like Middle Atlantic were offering pre-punched rack panels, let alone Neutrik coming out with panel mount males and females that mounted in the same size holes with matching mounting points. No; males went in 3/4" holes while females required 15/16th " holes. Mounting holes for males were on each connector's vertical centerline while female's mounting holes were skewed on an angle. Think Switchcraft D3F's and D3M's here. There was no space in the "shoe box" for any of the available racks of the day. A nearby, heavy steel, fab' shop thought they may be able to bend up, and weld, the fold-down hinged front paneled box design in something as thin as just shy of EIGHTH INCH THICK STEEL PLATE. This was "paper thin" in their world but; as they were in town, WANTED to do it for us and gave us a far better price than an out of town shop who'dve whipped it up in a much saner gauge, the Festival sprang for the box. Myself and another fine IA brother spent more than a day meticulously transferring my hand drafted paperwork to the ridiculously heavy gauge front panel followed by several days carefully drilling centre holes and mounting holes by HAND (as the front panel's hinge was WELDED to the box which was far bigger and heavier than could be accurately located AND supported by any of the shop's several drill presses. It took another couple of days to accurately position the hydraulic Greenlee and hand-pump it through ALL of those (Damn) centre holes. By the time the box was positioned and secured on the wall, all of the cables routed in, organized to roll nicely with the hinge rather than 'hard-bending', meticulously dressed, routed, stripped, heat-shrunk, pre-tinned, impeccably terminated and tested: The IA made a lot of money installing this box. Front panel labeling was accomplished with custom fabricated engraved Lamicoid continuous strips running across the full width of the box above each row of connectors so you could read the labels without having to lift a mated connector's cable to read its designation. A small mountain of 3' - ish patch cables were hand assembled in house along with a couple of dozen shorter cables only required to work within the upper few rows where the designated mic level section was located. The Festival actually sprung for a 27 pair, installation grade, multi-cable to replace the totally absurd collection of random lengths of individual cables of differing types (solid and stranded conductors of varying gauges with at least four types of shields) extended 'helter skelter' spliced with anything from unsoldered twists and tape, through Marrettes and butt-splices (appreciate these were all operating at mic level for about 150' through the attic area lighting coves and their delightfully tuneful SCR dimmers by the time they'd wended their way from the orchestra loft out of sight above the stage)
And they wondered why the mic lines buzzed.
When the XLR patch was complete, it was neat, tidy and legibly labelled. Everything worked. Taxi cabs were no longer a threat and NOTHING hummed.
It was all there and working flawlessly when a new lady entered my life and I left the virtually year round position behind in favor of a seasonal gig driving a multi track facility in their Avon's basement. The person who followed me was from a recording environment in Toronto. The first thing he told them was the XLR patch HAD to be replaced with a traditional RTS jackfield. To keep costs down, they went with a Canadian product from Farrtronics. A few seasons later, when the new lad quit mid season, I was pressured into returning to pick up a full rep' in mid season. Dropping into any established production, cold turkey in mid run can really raise your adrenaline but at least your facing the same production 8 times per week. Try dropping into 8. or more, different productions running in rep' where they're performing up to 10 performances weekly with cross-cast individual Equity members maxing at their contractual 8 per week limit. If you want to seriously raise your adrenaline try picking up a 10 or 12 show rep' when every day's a different show, the matinee's are never the same as the evenings and days pass before your first show comes around again. Doing this in the multiple open reel, pre digital console era really got your heart pumping, separated the 'wheat from the chaff' and the posers from the pro's.

Oh! The new patchbay kicker was I discovered, and tracked down, an intermittent in the RTS style patch my replacement just HAD to have. It wasn't any fault of Farrtronics. An IA lx who'd been pressed into soldering the field wiring connections had looped one conductor of a balanced pair through an eyelet and left it there UNSOLDERED.
"FMEng" is spot on with his assessment of patch bays in our current times.

I've gotta quit posting meandering, off topic, novellas like this before I'm confused with my old on-line aquaintance Brian; the "ship" that sailed me into this forum in the first place.
Toodleoo!
Ron Hebbard.
 
Ron, that sounds like quite a project to do.

Patch bays are OK when they are used frequently. When they sit un-touched, they get flakey. The problem is that in most installations, they are used very rarely. I'll go out on a limb and say that most installations that have them don't need them.

An XLR patch is a good way to go in some circumstances. It takes up a huge amount of space, but there isn't anything more reliable and easy to maintain.

A local concert hall has an audio recording booth. The original designer, who was a longtime recording engineer, put in an XLR patch panel. It worked perfectly for decades. Recently, inexperienced, new staff wanted the space and converted to bantam patch panels. I warned them, and suggested they at least use the larger, long-frame type but they didn't take my advice.
 
Ron, that sounds like quite a project to do.

Patch bays are OK when they are used frequently.
When they sit un-touched, they get flakey.
Agreed F.M. Try leaving a pair of old 12 point fields (from the era when 12 points occupied 1 RU with labeling space BETWEEN the points) in a non climate controlled concrete bunker housing a pair of 10 K AM vacuum tube transmitters in a country field. On warm days / evenings one, or both, of the exhaust fans would kick in drawing 'make-up' air in through the filtered intakes. On cool evenings ALL the little darlings lived around the exhausts enjoying the warmer air. Include a pair of phasers for the tranni ends of the dual pattern / day-night 6 tower array and a 10 K dummy load with it's own cooling air in-out filters 'n vents and we had LOTS of opportunities for dampness (and univited "guests") to gain entry in addition to the door seals on the dual doored / wide entrance. This was in the era when a single (equalized) telco pair carried your input signal from the downtown studio location to the 'out in the sticks' TX site with a redundant equalized pair for back up plus an additional DC pair (zero xfmrs anywhere along their routes) selected and activated all of your remote control and metering functions. Gates and GE transmitters. Even the big (self wiping / silver contacted) RF contactors would have a bit of grief from time to time but at least they were 'exercised' twice daily swapping between day-night pattern changes. I don't recall the jack fields even having normalling contacts. All I'm recalling is at least 4 patch cables in essentially permanent residence. Actually, over the 13 years I dealt with them, we'd routinely give them a few vigorous twists any time we were up to the site for routine cleaning and maintenance. Even if the jack fields had have had normalling contacts I doubt we'd have ever used them as the greater contact areas of the plugs, coupled with the ease of access for cleaning and rotating them, was giving us darn fair reliability all things considered. Between two of us, we'd visit the place at least once every two weeks and never pass the jack fields without giving the plugs a few twists. I think I'm remembering a 3 hour scheduled 'off air' maintenance opportunity between 2:00 and 5:00 a.m. when management would permit us to intentionally allow us to "shut 'er down" if need be. Often, during rating periods, we'd pass on the shut down so long as we weren't foreseeing any pending disasters on our immediate horizon.
The problem is that in most installations, they are used very rarely. You raise, and emphasize, good points regarding use being the 'good guy' and stagnation the bad. I'll go out on a limb and say that most installations that have them don't need them.

An XLR patch is a good way to go in some circumstances. It takes up a huge amount of space, but there isn't anything more reliable and easy to maintain. Plus you gain much more space for labeling. Labeling those little bantam fields was the worst. Talk about trying to accommodate anything meaning full using any legible sized font.

A local concert hall has an audio recording booth. The original designer, who was a longtime recording engineer, put in an XLR patch panel. It worked perfectly for decades. Recently, inexperienced, new staff wanted the space and converted to bantam patch panels. I warned them, and suggested they at least use the larger, long-frame type but they didn't take my advice. And how many DAYS has it taken before their first "episodes". Even brand new, some of those would begin exhibiting initial signs of pending doom within their first week.
Take care F.M.
Toodleoo!
Ron
 
Ha! Ratings periods are continuous now in the top 20 markets. Vacuum tube AM rigs, those were the days. I was probably born 20 years too late. Our big FMs still have a single-tube final, but the rest are are all solid state. The tube AM rigs are almost all relegated to auxiliaries.

Out of all the transmitter installations I have visited, I only recall one that had a working patch bay. That was a smaller, community station built by a skilled, but slightly misguided amateur. These days, there aren't enough audio devices in the transmitter chain to warrant a patch bay. Where there used to be a pile of processors is a single, digital box. (Thank you Mr. Orban!)

I lean toward a few, small, audio switchers so backups can be selected by remote control. My main transmitter is a 90 minute drive, with 7 miles of dirt or snow, so remote control of everything is important.
 

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