302USB Mixer (Behringer) voltage tolerance ?

Bob Carroll

Bob Carroll

Freshman
Jan 5, 2015
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The very small 5-input Behringer 302USB mixer does away with those awkward "proprietary connector" external power supply units.

Instead, the 302USB mixer is efficient enough to just use USB 5-volt power. It does require sacrificing 48V phantom in favor of 15V phantom.

What is a shame is that there is no 9VDC connection for use with pedalboard multi-outlet power supplies.

I figured a quick way to connect my Joyo PS 2 power supply to the 302USB USB port but it would use 9VDC instead of 5VDC.

Some music gear is very tolerant of voltage differences and some are not so tolerant.

An image of a hypothetical hookup is shown below. Any idea how tolerant the 302USB would be to 9VDC power?

9v-to-Behringer-302USB.png


BTW, the powered USB hub could not be used as a hub if connected to the reverse polarity cable shown.

I also found a 12VDC inline dimmer extension cable. I wonder if this dimmer could be used to reduce the voltage from 9 to 5 volts.

1-barrel-inline-dimmer-extender.png
 
Re: 302USB Mixer (Behringer) voltage tolerance ?

You already have AC going to your pedal board, put a cube tap on the end of the AC cord and use the PSU supplied with the mixer.

I'd be surprised if any of the kludges would survive 45% over voltage indefinitely.
 
Re: 302USB Mixer (Behringer) voltage tolerance ?

USB is regulated 5VDC, so I'd guess that there's very little in the way of power conversion circuitry inside that mixer. Meaning that 9V into the power input is likely to fry something. There are various ways to step 9VDC down to a regulated 5V, but unless you use a switching regulator, you'll need at least 500mA out of your pedalboard power supply. And even with a good switching converter, you'd be looking at needing 300mA out of your pedalboard supply. That amount of current is a bit much for many power supplies designed to run effects pedals that are designed to run off of 9V batteries.

Tim already gave you the correct answer, and you can use pretty much any USB charger if the one provided is bigger than you want.
 
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Re: 302USB Mixer (Behringer) voltage tolerance ?

Tim McCulloch said:
You already have AC going to your pedal board ...
Click to expand...

Only indirectly at the AC end of the 18VDC @ 1A Joyo power adapter supplying power to the Joyo PS.

On the PS, the first 7 of the 9VDC isolated output ports are rated at 100mA. The 8th is rated at 200mA.
 
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Re: 302USB Mixer (Behringer) voltage tolerance ?

Rob Timmerman said:
Except you still don't have enough power from your Joyo power supply. At 9V, you need AT LEAST 300mA ...
Click to expand...

How did you decide that 300mA is required? Most analog-only stomp boxes draw less than 15mA (20 times less).

The $50 Behringer Xenyx 302USB is a fairly stripped down analog mixer when USB functions are not being used.

302usb-hands.jpg
 
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Re: 302USB Mixer (Behringer) voltage tolerance ?

Bob Carroll said:
How did you decide that 300mA is required? Most analog-only stomp boxes draw less than 15mA (20 times less).

The $50 Behringer Xenyx 302USB is a fairly stripped down analog mixer when USB functions are not being used.

302usb-hands.jpg
Click to expand...

The power input on the back of the mixer states "5VDC 500mA". This is 2.5W. Allowing for a 90% efficient power converter, that brings us to 2.78W into the power converter. Dividing 2.78W by 9V gives just over 300mA.
 
Re: 302USB Mixer (Behringer) voltage tolerance ?

Bob Carroll said:
How did you decide that 300mA is required? Most analog-only stomp boxes draw less than 15mA (20 times less).

The $50 Behringer Xenyx 302USB is a fairly stripped down analog mixer when USB functions are not being used.

302usb-hands.jpg
Click to expand...

Rob has shown his math - why not just run an AC cable to your pedal board and call it a day? That's the ONLY thing stopping you from using this as intended. Presuming you are downstage, run your AC power on the downstage edge; you needn't run the AC with your signal line.
 
Re: 302USB Mixer (Behringer) voltage tolerance ?

Rob Timmerman said:
The power input on the back of the mixer states "5VDC 500mA". This is 2.5W. Allowing for a 90% efficient power converter, that brings us to 2.78W into the power converter. Dividing 2.78W by 9V gives just over 300mA.
Click to expand...

I misread the specs for the Joyo JP-02 multiport power supply. Port 8 supplies 9VDC at 500mA.

BTW, actual "real world" current draw can be, of course, much different from listed equipment power ratings.

Most analog-only stomp boxes draw less than 15mA and yet you seldom see any corresponding power supplies rated less than 100mA.



 
Re: 302USB Mixer (Behringer) voltage tolerance ?

Bob Carroll said:
I misread the specs for the Joyo JP-02 multiport power supply. Port 8 supplies 9VDC at 500mA.

BTW, actual "real world" current draw can be, of course, much different from listed equipment power ratings.

Most analog-only stomp boxes draw less than 15mA and yet you seldom see any corresponding power supplies rated less than 100mA.
Click to expand...
Well that may be true, but that's no excuse for under powering your equipment.
 
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