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16 of 16 people found the following review helpful
Phantom Power Issue - this may help
on 11 March 2014
This unit allows you to pass through a microphone XLR connection (on its way to an amp or mixing desk) and mix this with a monitor feed from the desk (via a quarter inch jack socket). The mixed signal is passed to the headphone output so that the user can select their personal mix in order to monitor the things that matter to them - or just get more of themselves in their headphone mix. You don't need to explain to a musician or singer all the possible uses that this has. Potentially it's a really useful device.
It has some really nice features for which the designers should get some credit:
- it has both sizes of headphone socket - though you can only use one at a time (according to the instructions - I've only used one)
- it has a mono/stereo switch - so you should hear things in both ears regardless of your setup.
- it has a ground lift in case you need to cure a ground problem.
- it allows you to adjust the mix input and mic level independently - these only affect the level that goes in to your headphones.
All in all a well thought-out and useful device at a very good price. What's not to like?
Well, there is/was an issue with phantom power. First, some people seem confused about this. Behringer never claimed that this unit could be powered by phantom power - the unit comes with a 12v mains adapter to serve its own power needs. The Behringer website claimed that the mic output [to the mixer or mic preamp] would pass phantom power through the device to the mic, provided the unit was plugged in to a mixer that provides phantom power. The problem, according to other reviews, is that it doesn't pass through the phantom power.
I did a lot of research on this problem and the truth seems to be that the earlier versions of this device were either wrongly designed or used the wrong components during manufacture. This gets a bit technical so bear with me. The problem is that two of the internal capacitors should have been 'non-polar' types (sometimes called bi-polar) rather than regular polarised capacitors. If you replace the relevant capacitors with the correct type then the unit will pass through phantom power properly. If you have a unit that doesn't properly pass phantom power, and you're confident of your soldering skills, then you can replace the capacitors marked C5 & C6 with equivalent non-polar types - they're 10uF 50v jobs. You obviously do this entirely at your own risk.
Having said all that...I've just bought one of these and it has the correct capacitors already installed! So, if you have a recent version of this unit then it should pass through phantom power correctly - mine does. Mine has a date code of 1311 on the back [possibly meaning 11th week of 2013?]. So it looks like Behringer has sorted out the problem with phantom power.
I'm very happy with the unit. I actually use it for a headphone feed in a vocal booth and it does the job well. Hopefully this clarifies the phantom power issue for everyone.
Bottom line is: earlier units didn't properly pass phantom power, but current units seem to be OK.
Edit: Just a comment to address some other reviewers who state that this isn't an amplifier. It most definitely IS an amplifier, it's not simply a passive device. If you take it apart (which I don't recommend) then you'll see that the 12v power input actually feeds two dual op-amp ICs on the main circuit board - that's an amplifier! However, the level of amplification is good but not huge. If you're in a studio, or you want a bit of extra juice from your laptop output then this is probably going to be OK. If you're a DJ in a very loud club, it may not be sufficient - in which case you may also need to look at getting better hearing protection...
Edit 2: Another review elsewhere on web suggests that there's a slight drop in phantom power as it passes through. I've just measured the phantom power on mine and it gets passed through with no drop at all (measured to the nearest 0.1v). Looking at the circuit, there's no reason for any phantom power to be consumed by it.
Edit 3: In a recording setup you may be worried about passing a signal from a really good mic through such a cheap piece of kit. I know I was. I've now done a careful noise and signal comparison - it doesn't seem to affect the mic signal to any measurable extent. Looking at the circuit, there's no reason why it should, but it's nice to know.