Skip to main content

Notice

Please note that most of the software linked on this forum is likely to be safe to use. If you are unsure, feel free to ask in the relevant topics, or send a private message to an administrator or moderator. To help curb the problems of false positives, or in the event that you do find actual malware, you can contribute through the article linked here.
Topic: Advantages re: AC Powered USB Hub vs Bus Powered for audio interface.  (Read 892 times) previous topic - next topic
0 Members and 1 Guest are viewing this topic.

Advantages re: AC Powered USB Hub vs Bus Powered for audio interface.

I know the obvious, ie additional ports and so on;  but are there any (theoretical) performance benefits wrt noise floor, phantom powering of condenser mics, headphone output performance etc?    I have two interfaces.  Steinberg UR22C & Soundcraft Signature 22 MTK. 


Y'all the best.  Thank you. 

TR
No.

Re: Advantages re: AC Powered USB Hub vs Bus Powered for audio interface.

Reply #1
USB power tends to be noisy which is no problem for the digital data but sometimes that noise gets into the analog electronics.    Some computers have more-noisy power than others and some interfaces have better filtering than others.  

If you hear it, it's usually a high-pitch whine, either from the switching power supply or from all the data/switching inside the computer.   (Even on battery, a laptop has switching voltage regulators.)

The mic preamps are most-sensitive to noise since they are high gain and they amplify noise along with the signal.

Re: Advantages re: AC Powered USB Hub vs Bus Powered for audio interface.

Reply #2
Externally powered hubs are nice since you can pick the power supply.  Usually doesn't matter, but for really sensitive instrumentation I've used low-noise linear power supplies with hubs before.

Re: Advantages re: AC Powered USB Hub vs Bus Powered for audio interface.

Reply #3
Ideally the analogue modules would have their own source of power separate from USB.
It's your privilege to disagree, but that doesn't make you right and me wrong.

Re: Advantages re: AC Powered USB Hub vs Bus Powered for audio interface.

Reply #4


The mic preamps are most-sensitive to noise since they are high gain and they amplify noise along with the signal.
thank you sir! On that note, ive seen this on a pro audio forum :
Quote
"Because of the severe power constraints of USB bus powering, the headphone outputs, and often the phantom mic power (mic current capability) are limited to power levels that are far less than ideal"
  is there any truth to the notion that mic preamps,phantom power ,  headphone outputs etc will perform worse on bus power?
No.

Re: Advantages re: AC Powered USB Hub vs Bus Powered for audio interface.

Reply #5
Externally powered hubs are nice since you can pick the power supply.  Usually doesn't matter, but for really sensitive instrumentation I've used low-noise linear power supplies with hubs before.

Thank you @saratoga @fooball
No.

 

Re: Advantages re: AC Powered USB Hub vs Bus Powered for audio interface.

Reply #6
is there any truth to the notion that mic preamps,phantom power ,  headphone outputs etc will perform worse on bus power?
That depends on how well the device filters noise from the bus power and how much power the bus allows it to draw.

I would guess it's probably cheaper to rely on an external filtered power supply than it is to build adequate filtering into the device, especially if there's no guarantee that the bus can provide enough power in the first place. (Although USB-C might solve the bus power issue, now that there's a standard for supplying up to 240W!)

Re: Advantages re: AC Powered USB Hub vs Bus Powered for audio interface.

Reply #7
With care USB can be fine. There is enough power for headphones and noise can be filtered. But it's often easier to just use a cheap external power supply at a higher voltage rather than clean up USB+5v.

Re: Advantages re: AC Powered USB Hub vs Bus Powered for audio interface.

Reply #8
is there any truth to the notion that mic preamps,phantom power ,  headphone outputs etc will perform worse on bus power?
That depends on how well the device filters noise from the bus power and how much power the bus allows it to draw.

I would guess it's probably cheaper to rely on an external filtered power supply than it is to build adequate filtering into the device, especially if there's no guarantee that the bus can provide enough power in the first place. (Although USB-C might solve the bus power issue, now that there's a standard for supplying up to 240W!)
thank you for the input sir!
No.

Re: Advantages re: AC Powered USB Hub vs Bus Powered for audio interface.

Reply #9
With care USB can be fine. There is enough power for headphones and noise can be filtered. But it's often easier to just use a cheap external power supply at a higher voltage rather than clean up USB+5v.
yessir, I've done just that and ordered an external supply.  Thank you so much!
No.