Rode VXLR Adapter at DVinfo.net

Ansel Brandt · May 24th, 2011, 04:45 PM

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

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

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

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

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

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

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

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

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.

May 24th, 2011, 04:45 PM	#1
Ansel Brandt New Boot Join Date: Jun 2010 Location: Vancouver, Canada Posts: 24	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).

May 25th, 2011, 05:49 AM	#2
Steve House Inner Circle Join Date: Mar 2005 Location: Hamilton, Ontario, Canada Posts: 5,742	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. __________________ Good news, Cousins! This week's chocolate ration is 15 grams!

May 25th, 2011, 09:29 AM	#3
Ansel Brandt New Boot Join Date: Jun 2010 Location: Vancouver, Canada Posts: 24	Re: Rode VXLR Adapter 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. Attached Thumbnails

May 25th, 2011, 03:44 PM	#4
Steve House Inner Circle Join Date: Mar 2005 Location: Hamilton, Ontario, Canada Posts: 5,742	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. __________________ Good news, Cousins! This week's chocolate ration is 15 grams!

May 25th, 2011, 04:43 PM	#5
Jon Fairhurst Inner Circle Join Date: May 2006 Location: Camas, WA, USA Posts: 5,513	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. __________________ Jon Fairhurst

May 26th, 2011, 12:59 AM	#6
Ansel Brandt New Boot Join Date: Jun 2010 Location: Vancouver, Canada Posts: 24	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.

May 26th, 2011, 03:35 AM	#7
Steve House Inner Circle Join Date: Mar 2005 Location: Hamilton, Ontario, Canada Posts: 5,742	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). __________________ Good news, Cousins! This week's chocolate ration is 15 grams!

May 26th, 2011, 06:04 AM	#8
Jon Braeley Major Player Join Date: Oct 2007 Location: Miami, FL Posts: 528	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?

May 26th, 2011, 11:10 AM	#9
Ansel Brandt New Boot Join Date: Jun 2010 Location: Vancouver, Canada Posts: 24	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.