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Gear / Technical Help => Remote Power => Topic started by: bryonsos on December 31, 2011, 10:01:46 AM

Title: Anyone tried 5V external (USB) power for MixPre?
Post by: bryonsos on December 31, 2011, 10:01:46 AM
Does it work? Thanks in advance!
Title: Re: Anyone tried 5V external (USB) power for MixPre?
Post by: rastasean on December 31, 2011, 04:09:39 PM
interesting question! I have never seen the mixpre cable terminated to USB before but i guess that doesn't mean its not possible. Are you going to make it or ask ted to make one?
Title: Re: Anyone tried 5V external (USB) power for MixPre?
Post by: bryonsos on December 31, 2011, 05:10:29 PM
I can't think why it wouldn't work since it's rated for 5-17 VDC. Unless somebody speaks up and says it doesn't work, I'll get Ted to build me one. I've got a USB battery I bought to power a 661 that I just sold, so I'm trying to find another use for it. I'll let you know if it works out.
Title: Re: Anyone tried 5V external (USB) power for MixPre?
Post by: page on January 01, 2012, 08:11:04 PM
I can't think why it wouldn't work since it's rated for 5-17 VDC. Unless somebody speaks up and says it doesn't work, I'll get Ted to build me one. I've got a USB battery I bought to power a 661 that I just sold, so I'm trying to find another use for it. I'll let you know if it works out.

what's the amperage draw rating on it?
Title: Re: Anyone tried 5V external (USB) power for MixPre?
Post by: Jamos on March 19, 2015, 08:27:08 PM
Bumping an old topic.
Anyone try this recently? 

I just had a couple USB > Hirose cables made, and want to power the MixPre from a RavPower Li-ion USB battery.

With this rig connected, the MixPre seems to power up and pass signal fine, but the Power LED does not light on it.
It does light when powered via AA batteries.

I'm going to run some tests tomorrow to see how long it can go.
Title: Re: Anyone tried 5V external (USB) power for MixPre?
Post by: DigiGal on March 19, 2015, 09:07:30 PM
It will not work for a MixPre-D which requires a higher voltage.

For any previous version of MixPre that only requires 5VDC to operate a USB to Hirose 4 pin cable should work just fine, though I'd recommend using a beefy USB cable to start with, one that uses lower gauge wires internally to handle current requirements.
Title: Re: Anyone tried 5V external (USB) power for MixPre?
Post by: bryonsos on March 19, 2015, 09:13:29 PM
For the MixPre, it works, but the battery light doesn't light up for some reason. I did a set 1 vs set 2 comp with DVD batteries and couldn't tell the difference. I'm using a GAK cable.

It will not work for a MixPre-D which requires a higher voltage.

For any previous version of MixPre that only requires 5VDC to operate a USB to Hirose 4 pin cable should work just fine, though I'd recommend using a beefy USB cable to start with, one that uses lower gauge wires internally to handle current requirements.
Title: Re: Anyone tried 5V external (USB) power for MixPre?
Post by: Benderman11 on March 19, 2015, 11:04:21 PM
Would this work for,the sound devices 442 also?
Title: Re: Anyone tried 5V external (USB) power for MixPre?
Post by: Jamos on March 22, 2015, 02:14:28 PM
I got confirmation from SD that powering via a 5V USB source should work fine. 
Still need to ask them about why the power LED doesn't light...

But I did a test yesterday with a 13000 mAh RavPower battery and the MixPre amplifying two Neumann km184 mics.
The MixPre was on and active for 8 hours.  I disconnected everything and checked the battery - it was not even down one blip (technical tem) on it's battery meter.

Should work fine with a 442, as they list its specs as 5-18V DC.
Title: Re: Anyone tried 5V external (USB) power for MixPre?
Post by: DSatz on March 23, 2015, 08:48:19 AM
USB ports differ as to how much current they can reliably supply at 5 VDC. It should never be assumed (without testing) that any given USB device can power your MixPre--and if other devices are also plugged in, they could reduce the available current at the MixPre's socket, depending.

There are standards as to the current that a USB port "shall" be able to supply, but they differ among USB versions 1.0, 1.1, 2.0, 3.0 etc., and the startup current is one thing while sustained availability is another. Plus there's a tolerance range around the 5 Volts, which may mean that in some cases the "5 Volts" you're getting from the port isn't enough to reach the "5 Volts" lower limit of the MixPre.
Title: Re: Anyone tried 5V external (USB) power for MixPre?
Post by: Jamos on March 23, 2015, 05:46:36 PM
USB ports differ as to how much current they can reliably supply at 5 VDC. It should never be assumed (without testing) that any given USB device can power your MixPre--and if other devices are also plugged in, they could reduce the available current at the MixPre's socket, depending.

There are standards as to the current that a USB port "shall" be able to supply, but they differ among USB versions 1.0, 1.1, 2.0, 3.0 etc., and the startup current is one thing while sustained availability is another. Plus there's a tolerance range around the 5 Volts, which may mean that in some cases the "5 Volts" you're getting from the port isn't enough to reach the "5 Volts" lower limit of the MixPre.

All interesting points!
The folks at Sound Devices have told me:
"with 2 phantom powered mics connected with gain turned all the way up the MixPre was pulling 310mA when connected to a 5v supply".

So if it's pulling a maximum of .3 amps through the USB cable, that should be fine in this application.  I suppose the SD 442 could pull probably double that amperage, but that's still under 1 amp, which should still be fine with most common sized USB cables.

I've got a question into SD regarding at what voltage the MixPre will shut itself down.
Title: Re: Anyone tried 5V external (USB) power for MixPre?
Post by: Benderman11 on April 01, 2015, 11:29:21 PM
Total SD newbie...I just got my Usb > hirose 4-pin.  Plugged into 442 and the battery LED indicator is flashing.  I then went through all external battery settings and got the same result with each, light continues to flash. 

Any ideas what I may be doing wrong?
Title: Re: Anyone tried 5V external (USB) power for MixPre?
Post by: Ultfris101 on April 02, 2015, 12:54:52 PM
check the amperage output of the USB port you are using. 1A and up is more common now because tablets typically require more, but 0.5A has been common historically if the adapter was intended just for a mobile phone.

this is something I've encountered.
Title: Re: Anyone tried 5V external (USB) power for MixPre?
Post by: Benderman11 on April 02, 2015, 09:48:19 PM
I have 1 & 2 amp USb ports on a 20,000mAh battery.  I 'm suspicious that because the battery output is 5V, the SD442  (5-18V DC  snput ) the machine just thinks the external battery is dying? 

Update:  SD442 had no issues running on 5V USB power and supplying 48V phantom power to 4 mics.
Title: Re: Anyone tried 5V external (USB) power for MixPre?
Post by: jmitchell on February 27, 2017, 01:45:49 PM
I have 1 & 2 amp USb ports on a 20,000mAh battery.  I 'm suspicious that because the battery output is 5V, the SD442  (5-18V DC  snput ) the machine just thinks the external battery is dying? 

Update:  SD442 had no issues running on 5V USB power and supplying 48V phantom power to 4 mics.

Were you using the 1a port or the 2a port? 
Title: Re: Anyone tried 5V external (USB) power for MixPre?
Post by: obaaron on May 08, 2017, 10:54:42 PM
I have 1 & 2 amp USb ports on a 20,000mAh battery.  I 'm suspicious that because the battery output is 5V, the SD442  (5-18V DC  snput ) the machine just thinks the externals battery is dying? 

Update:  SD442 had no issues running on 5V USB power and supplying 48V phantom power to 4 mics.

Wow....this is great gonna have a cable made for my mixpre!
Title: Re: Anyone tried 5V external (USB) power for MixPre?
Post by: tbone65 on October 30, 2017, 08:40:33 PM
i tried using a 5 volt phone charger battery.it ran the three channels for 18 hours with phantom on.