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Author Topic: OTARI MX5050 mk3 HELP!!!!!  (Read 6346 times)

operator159

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OTARI MX5050 mk3 HELP!!!!!
« on: September 06, 2010, 11:33:58 AM »
Hello,

I'm a bit of a noob, please forgive me if I ask any stupid questions.

I'm running a Tascam M-512 Mixer, I have the 8 buss outputs wired to a balanced 1/4 inch patch bay, which I then have patched in to my Otari MX 5050 mk3. I'm getting an outrageously quiet signal into my tape machine and I don't know why. When I patch the busses on my Tascam into my soundcard, they all sound great. I thought it may have been a problem with converting the XLR outputs to 1/4 inch, but when I wired an XLR directly from the buss to the tape machine, same problem. I'm wondering if it's a pin configuration problem? If it is, do I have to reconfigure the cables to match? is there some sort of way to use the grounding mechanisms for my patchbay? I believe my Otari is Pin 3 Hot, but I can't find a manual for the M-512.

Any help is GREATLY appreciated.

Thanks,
Nyles

Offline ironbut

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Re: OTARI MX5050 mk3 HELP!!!!!
« Reply #1 on: September 06, 2010, 12:03:02 PM »
Hi Nyles,

Welcome to the forum.
It does sound like a pin configuration problem since most gear is wired with pin 2 hot.
Since you wired it up yourself, just try switching pins 2 and 3 on your cable.
steve koto
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operator159

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Re: OTARI MX5050 mk3 HELP!!!!!
« Reply #2 on: September 06, 2010, 12:23:21 PM »
Can I use the grounding tabs for my patch bay to fix this? or do I have to re-solder the xlr connectors going to the tape machine?

Offline ironbut

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Re: OTARI MX5050 mk3 HELP!!!!!
« Reply #3 on: September 06, 2010, 03:21:22 PM »
I'm not familiar with the mixer so there's always a chance that there's a more expedient way to do this.
The most direct way is to solder a pair of adapter cables dedicated for the Otari. It's probably easier to do it on the XLR end since there's more room. New XLR's are cheap enough so if it's a hassle to get into the ones you already have, just buy a couple of Switchcrafts (be sure they're the right gender), snip off the old ones, strip and solder the wires to the new XLR.

So, if you have a TRS on the other end, you want;
Tip> pin 3 (instead of 2)=hot
Ring> pin 2 (instead of 3)=cold
Sleave> pin 1 (ground is always pin 1 since it's designed slightly differently)=ground
steve koto
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Offline Bruce B

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Re: OTARI MX5050 mk3 HELP!!!!!
« Reply #4 on: September 06, 2010, 09:35:19 PM »
You might want to check these forums. They seem to claim it's a -10db instead of a +4db mixer. As they say, XLR does not guarantee +4.

Also like the above post suggests... pin 3 hot.


http://www.gearslutz.com/board/high-end/28897-tascam-m-512-worth-using.html

http://homerecording.com/bbs/showthread.php?t=164481
Puget Sound Studios
Mastering & Post Production
Seattle, WA

Offline ironbut

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Re: OTARI MX5050 mk3 HELP!!!!!
« Reply #5 on: September 06, 2010, 10:47:12 PM »
That 14 dB could be what your hearing. IIRC the Otari should have a back panel switch that toggles between +4 and-10 dB levels. You may not need to do anything with the cables to get the levels up closer to normal. I believe that the balanced input is transformer coupled and that switch would bypass the input transformer which is probably a 2:1 or 1.5:1 stepdown.
steve koto
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operator159

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Re: OTARI MX5050 mk3 HELP!!!!!
« Reply #6 on: September 06, 2010, 10:55:25 PM »
So I've re-wired pins 2 and 3 on the XLRs going into the Otari's Inputs, and it's made a bit of a difference. Thanks so much!

Ironbut, thanks for the suggestion, let me just see if I have this straight: My M-512 busses send a -10dBu output, thus making it ideal for me to use the Low setting on the input panel on the back? will this negate the pin 2/3 exchange I did today? or will both changes make my setup ideal?

Also, will I have to re-wire pins 2 and 3 on the output XLRs as well? haven't got that far yet.

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Re: OTARI MX5050 mk3 HELP!!!!!
« Reply #7 on: September 06, 2010, 11:17:50 PM »
Switching the pins make the absolute polarity correct on the inputs. If your mixer is indeed only putting out a -10dB signal than the pin change and switching to the low setting on the back panel will make the inputs to the Otari correct. If you want to have absolute polarity on the outputs you have to change the pin connections there too.
If you plan to do much processing of the signal coming from the Otari, it's probably a good idea to switch the outputs too.
steve koto
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Offline Tim

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Re: OTARI MX5050 mk3 HELP!!!!!
« Reply #8 on: September 06, 2010, 11:50:54 PM »
Switching pins 2 and 3 on any balanced XLR output (or input) will only change absolute polarity.  It will have zero effect on signal levels.  For now, just leave all pin 2/3 connections where they are (or where they were) and find out what is causing the low meter readings on your tape deck: 

-Connect an XLR cable directly from the mixer to the tape deck.

-Make sure the XLR cables are wired correctly (as in all pins have continuity and that pins 2 or 3 are not grounded).

-Make sure that the mixer is producing it's proper +4dbm output at the XLRs (this is done by seeing a 0VU peak indication on the mixer master output meters).

-Make sure the tape deck front-panel input level pots and cal/uncal switches are correctly set.  Also check for any input sensitivity switches on the rear panel (if any).
 
Tim Leinbaugh
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with RTR specialty.