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TA3f to TA5f (Lectrosonics)

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I'm using some XLR's to make some custom cables for my 788t. I can't seem to find anything on soldering these 2 connections. Any help would be great.

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I'm using some XLR's to make some custom cables for my 788t. I can't seem to find anything on soldering these 2 connections. Any help would be great.

From what connection on the 788 to Lectro TX line in? If the output on the 788 is a balanced connection then it's pin 1 to pin one for the ground. Pin 2 on the the TA3 to pin 5 on the TA5 for line in. Pin 3 on the TA3 goes to pin 3 on the TA5 for line level.

Eric

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Ya, I saw a small diagram in one of my smqv manuals. But not having done this before u was a bit confused. When you say website... Lectro or SD's?

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Ya, I saw a small diagram in one of my smqv manuals. But not having done this before u was a bit confused. When you say website... Lectro or SD's?

Lectro under the "support" tab. Disregard the Senator, he offers nothing of any value.

Eric

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post-125-0-90831400-1342643638.jpg

Here's the wiring diagram from our site. Note Fig. 7 is 1 and 5

Best Regards,

Larry Fisher

Lectrosonics

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Larry: that would bring us to that diagram then ? (lower on the website's wiring diagrams for UHF txs w/ 5 input jacks)

TA3 : shield (pin 1) , audio (pin 2) then simply discard pin 3 on the TA3's side ?

Just to re-confirm as I was going to use that diagram that has no pin numbers...

post-1129-0-67384300-1345991532.jpg

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Larry: that would bring us to that diagram then ? (lower on the website's wiring diagrams for UHF txs w/ 5 input jacks)

TA3 : shield (pin 1) , audio (pin 2) then simply discard pin 3 on the TA3's side ?

Just to re-confirm as I was going to use that diagram that has no pin numbers...

That is the correct wiring for a balanced but not floating output, which is the most common. If you aren't sure if the balanced output is referenced to ground (center tapped or not floating) then simply wire it up as you show. If the signal is weak and sounds thin, then it may be a floating output (not as common) and pin 3 of the output TA3 will need to be taken to ground. Ideally you would do this at the TA5 end by tying the inverted audio (out of phase) output to ground (pin 1) of the TA5.

Best,

Larry F

Lectro

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Hello,


I am trying to confirm the best pinout for a connection between Sound Devices 6 series recorders and Lectrosonics SM series transmitters.

 

A Sound Devices tech notes page, which I found here:

 

https://www.sounddevices.com/tech-notes/mixer-interconnection-with-lectrosonics-wireless

 

seems as if it could be helpful, but I am concerned that the devices it discusses are much older, and perhaps different, than the current  offerings from both companies.

 

I have noticed differences between the output configuration of the 442 and 302 examples and wonder how the 6 series (especially the 633) compares and contrasts.

 

 

 

On page 13 of the Sound Devices 633 manual I found a note:

 

"(Pin 1 = Ground, pin 2 = Hot (+), pin 3 = Cold (-))   Float pin 3 to unbalance."

 

I am aware of the Lectrosonics pin out charts, but the comments about floating have left me somewhat confused with regards to the ideal connection between the Sound Devices X1, X2 TA3 outputs and Lectrosonics SMQV beltpacks.

 

I will appreciate it if someone can help with an explanation.

 

Thank you!

 

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Hello,

 I searched around and found the Lectrosonics MC49 TA3 to TA5 cable which is described as intended for use between mixer outputs and transmitter inputs for wireless camera hops.

 

 The data sheet shows the mixer's output Pin 3 is connected to the transmitter's Pin 1,4.

 

MC49_TA3-TA5.jpg

 

 I am confused by the explanation provided in a post above which refers to the alternate pin out:

 

LineLevels.jpg

 

On 8/26/2012 at 12:38 PM, LarryF said:

 

That is the correct wiring for a balanced but not floating output, which is the most common. If you aren't sure if the balanced output is referenced to ground (center tapped or not floating) then simply wire it up as you show. If the signal is weak and sounds thin, then it may be a floating output (not as common) and pin 3 of the output TA3 will need to be taken to ground. Ideally you would do this at the TA5 end by tying the inverted audio (out of phase) output to ground (pin 1) of the TA5.

 

I am left with the impression that the MC49 cable sold by Lectrosonics is wired for what has been described as the less common circumstance.

 

Honestly, I am confused by the terms "ground" and "floating" as used in this discussion and the operating manuals. I would have supposed that ground is always floating on battery powered systems, that ground may or may not be floating on AC powered systems, and that any balanced signal transmission is referenced to some zero potential which may or may not be floating.

 

I am not trying to make a big deal about the nomenclature, or dwell on who said what. I am just hoping to learn what is known to be ideal for using the TA3 outputs on a 633 mixer to feed a wireless hop through a Lectrosonics SM series transmitter.

 

I have read the relevant manuals and corresponded with Sound Devices and the information seems ambiguous.

 

Can someone help out by relating their experience with the connection I am trying to learn about?

 

Thank you.

 

 

 

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The top diagram is what I always use. You ground pins 1 & 3 on the TA3 to pins 1 & 4 on the TA5 ends and connect pin 2 on the TA3 to pin 5 on the TA5. Always works just fine.

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What Eric said.

 

They're both actually the same diagram except that the first one shows that if you're coming from a balanced output you'd tie pin 3 to ground in the XLR3 or TA3 connector.

 

BTW, to eliminate a common misconception among the unknowing:  Even though balanced outputs typically use one of the above two connectors (or sometimes a TRS phone plug), the connector is not what makes an output balanced.  An output being balanced is due to the circuitry of the output having an equal potential of each signal leg to ground).

 

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Thank you for the helpful information Eric.

I am curious about this idea:

 

On 8/26/2012 at 12:38 PM, LarryF said:

TA3 will need to be taken to ground. Ideally you would do this at the TA5 end by tying the inverted audio (out of phase) output to ground (pin 1) of the TA5.

 

Is this configuration intended to keep the unused reverse polarity signal off of the screen while dumping it directly to ground?

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Balanced outputs can be floating or center tapped (ground referenced). Unfortunately, they are converted to unbalanced outputs in two different and incompatible ways. In the floating output case,  one of the output points must be tied to ground when feeding a single unbalanced input. If it isn't, the audio will usually be very weak with little bass and accentuated highs.

 

In the ground referenced or center tapped case, one of outputs must be unconnected. If not, the signal will be very distorted and/or weak. Most electronically balanced circuits are center tapped or ground referenced since the circuity is much simpler and isn't as easily driven into clipping. However, floating outputs have the advantage of better noise and ground loop rejection.

 

So how do you tell which situation you have without reading the manual or trusting the manufacturer. Let's assume an XLR output that is on a piece of gear designed by a rational manufacturer. Use pin 1 for your unbalanced line shield (ground) and use pin 2 for your audio signal. While playing a tone or an audio signal, ground pin 3 to pin 1. You can do this with the shell of the XLR pulled back and a short piece of wire across the pins. If the signal improves dramatically, it is a floating output and you need to ground pin 3 to pin 1. If the signal drops dramatically, you are dealing with a ground referenced or center tapped output and you need to leave pin 3 float. 

 

If the signal doesn't drop much or increase much, (3 dB or so) you are dealing with a Lecto output or one very similar, that has build out resistors to sidestep the entire problem. In this case, it is slightly better to let pin 3 float.

Best Regards,

Larry Fisher

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Thank you for the detailed explanation.

 

I will go back and correspond with Sound Devices to ask how their XLR and TA3 outputs are configured.

 

In the meantime I stumbled upon an awkward comparison:

 

From the SMQV data sheet: Line Level Input Impedance 2.7kOhms

 

From the Sound Devices 633 manual specification page: TA3 Mic/Line: active balanced, pin-2 and 3 driven, for use with ≥3k ohm inputs 

 

I know, I know... reading the manuals can be hazardous. :-)

 

 

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22 minutes ago, alenK said:

Thank you for the detailed explanation.

 

I will go back and correspond with Sound Devices to ask how their XLR and TA3 outputs are configured.

 

In the meantime I stumbled upon an awkward comparison:

 

From the SMQV data sheet: Line Level Input Impedance 2.7kOhms

 

From the Sound Devices 663 manual specification page: TA3 Mic/Line: active balanced, pin-2 and 3 driven, for use with ≥3k ohm inputs 

 

I know, I know... reading the manuals can be hazardous. :-)

 

 

Close enough.  Not an issue.

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I think you might be over thinking this a bit.. For the time spent on this post, you could have built the cable already. Look at all of the accessory cables provided by Lectrosonics...these are tried and trusted configurations to get audio at line or mic level into their equipment..

Build yourself a set of line level cables.. And a set of mic level cables and then build some spares.. They definitely come in handy.

Sent from my SM-G935P using Tapatalk

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On 9/28/2017 at 12:04 PM, John Blankenship said:

 

Close enough.  Not an issue.

 

Yes, impedance bridge ratios are usually loose suggestions when you start with a ratio such as 1:10, which is often quoted as a good starting point.

 

With the Sound Devices 633 TA3 output impedance at 1kOhms and the SMQV input impedance at 2.7kOhms the bridge is 1:2.7 rather than Sound Devices suggestion of a minimum of 1:3.2. The difference between the two ratios is very small but the difference between either of them and 1:10 made me pasue and take notice.

 

I am confident that the SMQV input impedance will not cause the outputs of the 633 to melt due to excess current flow, but I do find the circumstance to seem a curiosity. I found humor in the idea that reading the manuals carefully can elicit more questions than answers.

 

Thank you.

 

 

On 9/29/2017 at 1:19 PM, mradlauer said:

I think you might be over thinking this a bit. For the time spent...

 

I am thankful that Lectrosonics' and Sound Devices' service departments both took the time to answer my specific questions. For my part, it was worth every minute to learn the details regarding this interconnection.

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