TP-027, Jerry Garcia / David Grisman wins a Writer's Choice Award from Myles Astor of Positive Feedback Online

Author Topic: Otari MX-5050 BII XLR Pin Configuration  (Read 6660 times)

Offline clio09

  • Newbie
  • *
  • Posts: 2
    • View Profile
Otari MX-5050 BII XLR Pin Configuration
« on: February 04, 2010, 09:09:44 AM »
Hello,

I'm new to the forum but I've acquired an MX-5050 BII and have a question about the XLR pin configuration. From the manual and what I've read these decks were configured as Pin 3 hot. When I took a look at the wiring on the XLR input and outputs on the deck itself there is an orange wire connected to Pin 2 and a white wire connected to pin 3. However, on the MIC input the orange wire is connected to Pin 3 and the white wire to Pin 2. So I assume the line inputs and outputs were rewired to Pin 2 hot. Can anyone confirm this for me? Is the orange wire the hot wire?

The reason I ask is because I played back a tape using XLR cables from the line output direct to my amps XLR input and the sound was somewhat diffuse, especially the center image. Any help is appreciated. Thanks


Offline Tim

  • Full Member
  • ***
  • Posts: 130
    • View Profile
Re: Otari MX-5050 BII XLR Pin Configuration
« Reply #1 on: February 04, 2010, 11:54:51 AM »
The diffuse center image is most likely cased by mis-wired XLR cables.  They are causing your speakers to be 180 degrees out of phase, hence the lack of center image.  Check that both of your XLR cables are wired exactly the same.

On Otaris, convention is pin 3 hot.  Either 2 or 3 can be hot.  It doesn't matter which, unless you are concerned with absolute phase.

Sorry, I don't know if the orange wire goes to pin 2 or 3.

I would go by which input (mic or line) has a fresh-looking solder job.   It's likely the one that been switched around (2 and 3).
Tim Leinbaugh
Service Technician
with RTR specialty.

Offline High and Outside

  • Administrator
  • Sr. Member
  • *****
  • Posts: 363
    • View Profile
Re: Otari MX-5050 BII XLR Pin Configuration
« Reply #2 on: February 04, 2010, 06:31:36 PM »
I'm with Tim, the symptoms indicate that one channel is out of polarity. If the wiring of both output connectors is the same, then suspicion falls on your cables.

Also, I wouldn't read too much into the colors of the wires on the line ins versus the mic ins. Although some manufacturers used Pin 3 Hot for their line ins and outs, the convention on microphones was pin 2 hot since the introduction of the XLR connector. So some pieces, including everything Ampex ever made, was pin 3 on the line ins, and pin 2 on the mic ins.
Paul Stubblebine
Managing Director, The TapeProject

Offline clio09

  • Newbie
  • *
  • Posts: 2
    • View Profile
Re: Otari MX-5050 BII XLR Pin Configuration
« Reply #3 on: February 05, 2010, 10:59:30 AM »
Thanks for the responses. To Paul's point, the MIC input is Pin 3 Hot according to the manual, so it does appear that my deck was rewired to Pin 2 Hot on the line inputs and outputs (the solder does look fresher than on the MIC input). So I will take both your advice and check that the cable is wired correctly.