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Duplex Box


Graves

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Anyone make their own? I made one using a 5 pin xlr (pin 1 shield, pin 2 +, pin 3 - mic / pin 4 tip, pin 5 ring for headphones) I grounded the shield on the stereo hp 1/4" jack to chassis of the 5 pin xlr. Mic works great, 48v works, but the headphones turn down when I turn up the volume from my SD 702t. Cable is Canare L-4E3-2P. Should I use a 6 pin xlr? I removed the ground from the headphone jack in the box and the same, actually, it works better with the ground removed, but still no volume adjustment, level goes down, not up. What am I missing? All solder joints are solid and resistance is at a minimum..... 000.5 or less on all connections using my multi meter.

Thanks,

John

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Anyone make their own? I made one using a 5 pin xlr (pin 1 shield, pin 2 +, pin 3 - mic / pin 4 tip, pin 5 ring for headphones) I grounded the shield on the stereo hp 1/4" jack to chassis of the 5 pin xlr. Mic works great, 48v works, but the headphones turn down when I turn up the volume from my SD 702t. Cable is Canare L-4E3-2P. Should I use a 6 pin xlr? I removed the ground from the headphone jack in the box and the same, actually, it works better with the ground removed, but still no volume adjustment, level goes down, not up. What am I missing? All solder joints are solid and resistance is at a minimum..... 000.5 or less on all connections using my multi meter.

Thanks,

John

I'm trying to understand why you used a 5 pin xlr and how it allows you connect a mic & phones to/from your 702. Normal convention would be a 3 pin XLR-F for mic input and a 1/4"TRS jack for head phone feed. Something like this one. There is a belt clip attached to the back of the box. Having seperate connectors eliminates a lot of potential problems.

Eric

post-21-130815094242_thumb.jpg

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Hi Eric,

I do have a box w/clip. The 5 pin XLR attaches at the bottom, then is wired to a F-XLR and F -1/4" TRS connector(s). The 5 pin XLR cable breaks out to M-XLR and M-1/4" TRS, which connects to the 702t. It looks very much like the PSC duplex box/cable, but I used XLR connectors instead of the multi-pin screw on connectors they use. Right now I'm only using 30' of cable, so not much of a run, but it seems like there's too much resistance in the cable?? I connected my ipod to the cable/box and I can hear the volume change, but I also get some aliasing, like it's a very low quality mp3, very strange...?????

My initial thoughts were (when I was making the cable/box) to drop the shield/ground of the headphones, because it's an unbalanced signal and wasn't needed, but I'm not sure what's going on? I wasn't sure if they (PSC or the like) used a resistor and/or cap in the box's wiring? I have seen them with a volume control built in, but wanted to keep it simple.

Thanks again for your help.

J

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Okay, I've seemed to have fixed the problem. I connected the ground from the 1/4" jack to pin 1 and removed the ground on the M-TRS connector going to the recorder, so there's only one common ground, pin 1 of the XLR input. For some reason, it only wanted a single ground connection??? Volume works with full stereo output.

Thanks Eric and Joshua, I truly love this forum.

J

Now I have to buy more Canare cable to make a longer run, pacific radio, here I come.

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Okay, I've seemed to have fixed the problem. I connected the ground from the 1/4" jack to pin 1 and removed the ground on the M-TRS connector going to the recorder, so there's only one common ground, pin 1 of the XLR input. For some reason, it only wanted a single ground connection??? Volume works with full stereo output.

Thanks Eric and Joshua, I truly love this forum.

J

Now I have to buy more Canare cable to make a longer run, pacific radio, here I come.

Glad I could help to solve your problem. What you've got now is a floating single ended ground. You should be able to reconnect the the ground at the recorder end of the TRS with no issues. What happened was that by connecting the ground to the chassis ground there was no ground as the chassis ground did not connect to the 702t. If you had originally connected the chassis ground to pin one all would have been fine.

Eric

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Hey John,

  I finished making a pair of these recently. The only thing left is to add on belt clips. Does anyone have a recommendation or online supplier for them? Otherwise I have a few lectrosonics spring clips from some UMs thaI changed over to the wire clips. I also put in a 5k potentiometer for the headphones( thank you Wyatt for the help with this!). When I have boomed, I got annoyed with not having control over my own volume.

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  • 4 weeks later...
  • 4 months later...

Does anyone have a recommendation or online supplier for them?

I called up Denecke and asked for a clip (as seen on their phantom PSU boxes). I think it was 8 bucks. Nice, hefty clip.

In other news, could anyone provide a part #/schematic for the headphone pot in the box? I have been looking to add one to my box for a while now...

Travis

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  • 1 month later...

Anyone make their own? I made one using a 5 pin xlr (pin 1 shield, pin 2 +, pin 3 - mic / pin 4 tip, pin 5 ring for headphones) I grounded the shield on the stereo hp 1/4" jack to chassis of the 5 pin xlr. Mic works great, 48v works, but the headphones turn down when I turn up the volume from my SD 702t. Cable is Canare L-4E3-2P. Should I use a 6 pin xlr? I removed the ground from the headphone jack in the box and the same, actually, it works better with the ground removed, but still no volume adjustment, level goes down, not up. What am I missing? All solder joints are solid and resistance is at a minimum..... 000.5 or less on all connections using my multi meter.

Thanks,

John

I also used 5 pin xlr for box input, which means that you have to wire up mic and headphone shields (ground signals) together, obviously, because you only have 5 pins to go to the box. To avoid shared ground signal for mic and headphones, you need 6 pins.

I tested my box on sound device mixer and both signals for mic and headphones were coming from mixer. But the gain of mic was little bit low than usual and when you'd turn up the gain it would have noise. I guess it's because of shared ground signal.

here's my box (headphone wires are disconnected)

rsaicj.jpg

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  • 2 years later...

Bringing this post back from the archives..

 

I would like to make a system with a detachable box and mixer end and then make several 5-pin extensions that can be used as needed. I would prefer to keep the wiring of the 5-pin extensions the same as standard stereo-mic wiring so that they could be used for that purpose as well.

 

So I'm wondering how many of you who use a 5-pin XLR for these boxes tie the grounds together for the headphones and microphone input? Is this a potential source for ground loop trouble or the standard method? As someone stated above a 6-pin would be ideal.

 

Thanks,

Derek

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  • 3 weeks later...
  • 2 years later...

Do you have any schematics on this?

On 3/1/2011 at 1:47 PM, graham said:

Hey John,

  I finished making a pair of these recently. The only thing left is to add on belt clips. Does anyone have a recommendation or online supplier for them? Otherwise I have a few lectrosonics spring clips from some UMs thaI changed over to the wire clips. I also put in a 5k potentiometer for the headphones( thank you Wyatt for the help with this!). When I have boomed, I got annoyed with not having control over my own volume.

 

 

th_b6adf0bb.jpg

 

 

th_90f23a7f.jpg

 

 

th_3e7d323e.jpg

 

 

 

 

Do you have any schematics on this?

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