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-   -   Rode VXLR Adapter (https://www.dvinfo.net/forum/all-things-audio/496364-rode-vxlr-adapter.html)

Ansel Brandt May 24th, 2011 04:45 PM

Rode VXLR Adapter
 
What exactly does it do? Could I use this as a compact substitute for a DI box in combination with a padded/attenuated cable?

there are often instances when I want to be able to record one channel of audio from an XLR mic input and another channel from a line level (2V) 3.5mm source, like say phone interviews using a cell phone.

i realize this could easily be done with a mixer, but i often don't have or want to carry a mixer with me. My Marantz PMD661 only allows one set of inputs to be used at once (both XLR or both from 3.5mm line-in).

Steve House May 25th, 2011 05:49 AM

Re: Rode VXLR Adapter
 
The VXLR is designed to adapt a 1/8 mono microphone such as the Rode VideoMic to plug it into a single XLR input.

Ansel Brandt May 25th, 2011 09:29 AM

Re: Rode VXLR Adapter
 
1 Attachment(s)
That much I already knew, I was wondering more how the wiring works from unbalanced to balanced.

I found this VXLR schematic, but I don't really know what's going on.

Steve House May 25th, 2011 03:44 PM

Re: Rode VXLR Adapter
 
When an XLR is used for balanced wiring, the normal case, pin 2 is signal hot, pin 3 is signal cold, and pin 1 is ground. As the schematic shows, pin 3 is shunted to ground, effectively unbalancing the XLR side of things. Meanwhile, at the 1/8 side, ground goes to XLR ground, left and right signal (should it be a stereo mic plugged into it) are connected together in parallel, combining them into a single mono signal, and sent to the XLR signal hot. So the VXLR is both a physical connection adapter and an unbalancer for the XLR input.

Jon Fairhurst May 25th, 2011 04:43 PM

Re: Rode VXLR Adapter
 
Beware that adapter for phantom powering of your lav. Not all lavs are happy to receive +48V.

Some adapters insert a zener diode or two to limit the voltage to your lav. That might protect it, but won't necessarily power your lav correctly. I bought a Sanken COS-11D and a cheap adapter. Didn't work. I ended up getting the real, $150+ active adapter, which works, sounds great, and makes a truly balanced XLR connection.

Hats off to Rode for making their lav work with a cheap XLR adapter, but note that the XLR cable signal won't be balanced, so avoid long runs.

Ansel Brandt May 26th, 2011 12:59 AM

Re: Rode VXLR Adapter
 
hmm...my iphone might not like phantom power either.

i didn't know you could send a balanced input a signal on only 1 pin. i just assumed that it would require a signal on both pins.

Steve House May 26th, 2011 03:35 AM

Re: Rode VXLR Adapter
 
Well you do have to have a complete circuit. But by grounding pin 3, you complete the circuit. Note that unbalancing an OUTPUT in this manner, such as feeding the output of a balanced mic or other device into an unbalanced input, results in only half the waveform getting used, thus there is a 3dB drop in level. Balanced output to unblanced input results in a signal drop. This adapter goes the other way, unbalanced output to balanced input (albeit functioning as if it was an unblanced input).

Jon Braeley May 26th, 2011 06:04 AM

Re: Rode VXLR Adapter
 
So could this adapter work with the Rode Videomic Pro and a recorder - say the Tascam DR-100 with XLR's?

Ansel Brandt May 26th, 2011 11:10 AM

Re: Rode VXLR Adapter
 
Well, that is the original purpose of the adapter. Rode has another XLR adapter (MICON-5) that provides somewhere between 2-5V of plug-in power for the Rode Lavalier when supplied with phantom, but has a MiCon connection instead of a 3.5mm TRS.


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