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ERIC HELP!!! Sennheiser G3 transmitter plug wiring...

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I have read all the posts. I have built some in the past, but gave them all away when I sold my G2 units. Now a buddy needs me to build him a couple for a job tomorrow...

The absolute correct, proper wiring for a transmitter mini plug fed from a FP33 at mic level, balanced! Yea, I know you don't have to have all that info, but what the heck.

GRACIAS..

MERRY CHRISTMAS...

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I have read all the posts. I have built some in the past, but gave them all away when I sold my G2 units. Now a buddy needs me to build him a couple for a job tomorrow...

The absolute correct, proper wiring for a transmitter mini plug fed from a FP33 at mic level, balanced! Yea, I know you don't have to have all that info, but what the heck.

GRACIAS..

MERRY CHRISTMAS...

From an xlr output to a female XLR. Pin 2 is positive, connect the shield/ground to pins 1 & 3. At the 3.5 mm male plug connect the positive to the tip, the shield/ground to the ground in the 3.5mm plug. It will be an unbalanced connection but don't worry it works.

Will look like these. Happy soldering.

post-22-0-91304200-1324664339.jpg

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P.S. Easy way to connect the shield/ground to pins 1 & 3 in the XLR. Fan out the shield and make two twisted tails, tin them and then solder one tail to pin 1 and the other to pin 3. It will look like a "Y" connector. A lot easier than trying to solder in a jumper from pin 1 to pin 3 or 3 to 1.

P.P.S. for a line level input connect the positive to the ring of the 3.5mm TRS plug.

Eric

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"P.S. Easy way to connect the shield/ground to pins 1 & 3 in the XLR. Fan out the shield and make two twisted tails, tin them and then solder one tail to pin 1 and the other to pin 3. It will look like a "Y" connector. A lot easier than trying to solder in a jumper from pin 1 to pin 3 or 3 to 1."

Thank you, Eric. All these years I have been using small gauge solid core wire to make little jumpers. Never occurred to me to split the shield the way you describe.

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Can I resurrect this?

I modified a CL100 Rx(TRS) to balanced XLR cable so I could use it with my SD 302 and G3 Tx - I did the following:

The SD302 demands that I float pin 3, so I do that.  I tie what I hope is the cold (white) wire directly to the ground, soldering both to pin 1.  I solder the hot (red) wire to pin 2.

As the TRS end is molded I can't visually see the wiring but the trusty ohmeter shows continuity between pin 2 and the tip of the TRS.  Pins two and three show continuity with the TRS sleeve.

I padded the 302 output down to -10 on a hunch that "/line" meant consumer line and the G3's seem to now work as a cam hop.

My question is this.  Aren't lav mics powered via the tip of the trs when using the G3 Tx? Does this present any danger to my 302 outs or is it negligable?  If not then can I assume that using that cable presents me with a usable, albeit mic level cam hop system?  If it's mic level then how comes my test run at -10 didn't present any distortion? 

I suspect the safest thing to do is to buy new TRS connectors and wire hot to the ring and ground the tip but this is seriously bugging me and sennheiser seem to be awfullt secretive about wiring conventions for these products...

Signed

Confused DIY cabling newb.

(be nice please)

 

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Here is what works. The female xlr is to be wired as follows for a MIC level feed from the 302 XLR.

The shield/ground is to be connected to pins 1 & 3. Best way to do that is to split the shield into 2 twisted leads and tin them before connecting to the XLR. The positive connection from pin 2 in the XLR goes to the tip of the 3.5mm TRS connector and the shield goes to the ground connection.

If you're going to feed the G3 at line level from the 302 then the positive goes to the ring tab. If you need to pad the line signal from the 302 a 10k ohm resistor in series with the positive feed will give you about 10db of pad, a 20kohm resistor will give you 20db of pad. Personally I prefer feeding the wireless from the mixout TA3 which is at -15 and will work just fine into the tx at line level. That way your main XLR's are free to feed something else. If you have any questions call me. 954-255-7628.

Eric

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Thanks Eric!

I had read that when wiring a mic level cable that some people like to solder in a capacitor to defeat the bias voltage from the Tx.  Presumably that's not necessary?  I'm going to switch to the hot-ring configuration anyway for line output - I'll look into it further.

One thing - I believe in the 302's case sound devices recommend that one floats pin three and not ground it when unbalancing the XLR output. 

 

I take your point about using the TA3  - however with my setup sometimes it's occupied!

Finally, boo to sennheiser for the molded connectors....grumble..







 

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"Personally I prefer feeding the wireless from the mixout TA3 which is at -15 and will work just fine into the tx at line level"

- I concur, the mixout works good, if you choose the XLR, that will need a pad, even for the SK100 bodypack transmitter's -10dB line input, in which the XLR output can be attenuated internally with the 302. The SK100 mic (tip connection) has bias current, so a blocking cap is recommended if using for a direct input.

Yes, SD recommends floating pin-3 on the XLR out for unbal. operation

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"Personally I prefer feeding the wireless from the mixout TA3 which is at -15 and will work just fine into the tx at line level"

- I concur, the mixout works good, if you choose the XLR, that will need a pad, even for the SK100 bodypack transmitter's -10dB line input, in which the XLR output can be attenuated internally with the 302. The SK100 mic (tip connection) has bias current, so a blocking cap is recommended if using for a direct input.

Yes, SD recommends floating pin-3 on the XLR out for unbal. operation

Interesting, I wasn't aware of that specific configuration for the 302. I believe the reason is I always recommend using the unbalanced TA3 2 channel mixout for tx feeds to keep the XLRS free for something else. Live & learn.

Eric

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Thanks Eric!

I had read that when wiring a mic level cable that some people like to solder in a capacitor to defeat the bias voltage from the Tx.  Presumably that's not necessary?  I'm going to switch to the hot-ring configuration anyway for line output - I'll look into it further.

One thing - I believe in the 302's case sound devices recommend that one floats pin three and not ground it when unbalancing the XLR output. 

 

I take your point about using the TA3  - however with my setup sometimes it's occupied!

Finally, boo to sennheiser for the molded connectors....grumble..

With the Sennheiser supplied 3.5mm TRS to XLRM, it's not a matter of if it will fail it's when it will fail. There is no way to repair that molded cable. You just throw it away and get one like this from me. Lifetime warrenty (my lifetime)

Eric

post-22-0-27717100-1372693135_thumb.jpg

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I like the idea of sending either left or right to camera (i.e. one mic feed or a mix of mics to my taste) rather than a mono summing of both L + R.  That said I could always float the L or R pin on the TA3 and achieve the same thing....

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I'll definitely keep this in mind for when my limited soldering skills inevitably test my patience to it's limit! :P

 

With the Sennheiser supplied 3.5mm TRS to XLRM, it's not a matter of if it will fail it's when it will fail. There is no way to repair that molded cable. You just throw it away and get one like this from me. Lifetime warrenty (my lifetime)

Eric

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I like the idea of sending either left or right to camera (i.e. one mic feed or a mix of mics to my taste) rather than a mono summing of both L + R.  That said I could always short out a pin on the TA3 and achieve the same thing....

Or you could use something like this. TA3 to L&R output connections. In this case it's to two TA5 connectors for a Zaxcom Nomad. If you use 2 XLRM connectors instead then you have the option of sending 2 channel audio.

post-22-0-51385400-1372694743_thumb.jpg

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"That said I could always short out a pin on the TA3 and achieve the same thing.."

- I have three cables for the 'Tape out' for mono usage, Left only; Right only and summed Left + Right. The L or R pins on the TA3 are floated when not used.. at least that's what I did.

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"That said I could always short out a pin on the TA3 and achieve the same thing.."

- I have three cables for the 'Tape out' for mono usage, Left only; Right only and summed Left + Right.

The L or R pins on the TA3 are floated when not used.. at least that's what I did.

That is correct as the TA3 is an unbalanced connection just like the unbalanced 2 channel feed for headphones. Now if you made a TA3 to a L&R 2 channel feed you'd have all the bases covered. Decisions, decisions.........;-))

Eric

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An explanation as to why SD says to float pin 3 in an unbalanced connection from the balanced XLRS. By connecting pins 1&3 to ground you lose 6db of output level at the input connection. Floating pin 3 keeps the output level the same from output to input. Works equally on mic or line settings.

Eric

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Thanks Rick/Eric - decisions indeed!!

It's Canada day here and therefore everything is closed.  I am therefore now in a huff because i can't go and buy connectors and spend the day making cables!!

Stupid Canada day....wanna make cables dammit!!!.... :(

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Now if you made a TA3 to a L&R 2 channel feed you'd have all the bases covered. Decisions, decisions.........;-))

'I've' done so long ago and have a few L/R stereo cables as well for my H2 backup or other 1/8" stereo in.

I put a very low profile 1/8" right-angle plug on it (photo below) so it doesn't stick out much and a small piece of gaff tape is easily applied over it for added security.

post-1774-0-18310900-1372715787_thumb.jp

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"That said I could always short out a pin on the TA3 and achieve the same thing.."

- I have three cables for the 'Tape out' for mono usage, Left only; Right only and summed Left + Right. The L or R pins on the TA3 are floated when not used.. at least that's what I did.

 Yes that is actually what I meant, despite wording something different! - let me go back and correct my post...

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The last paragraph...

Hopefully, this explanation has been lucid and edifying. If none of this is new to you, perhaps a job as Senior- or even Chief-Guru in the Sound Devices Technical Support Department is in your future. In the extremely remote case that one of the several Sound Devices Gurus who wrote this made a mistake, then please send corrections here, and the Guru(s) in question will be summarily terminated.

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Hey Eric!!!

 

Ok i know that this has been covered but i can't seem to wrap my mind around this wiring...i am a bit confused by the terminology shield/ground?...If you could please refer as red (hot) white (cold) and ground :)

 

I am about to make a TA3 (SD302 tape out) to locking TRS (for senny G2Tx) and want to make sure i do it right. I want the sum of both L&R to make a mono feed for scratch audio.

 

Also i am making the cable for the camera end (black magic pocket camera) locking TRS to standard TRS. Any special considerations for this cable?

 

Thanks!

 

 

p.s: I need it for tomorrow ;)

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