Audio Interfaces with USB Power ONLY?

[Pathfinder]

First I understand the "convenience" factor in certain situations. That's it though, for me. 

I so wanted the SSL 12 but refuse to not have an AC Power options. 

Just some scenarios from Google:

USB-only powered audio interfaces are problematic because the limited power available through the USB connection can lead to issues like noisy audio, inconsistent performance, especially with high-power requirements like phantom power for microphones, and potentially compromised sound quality due to the potential for power fluctuations from the computer's USB bus, impacting the sensitive analog circuitry within the interface. 

Key reasons why USB-only powered audio interfaces can be problematic:

Power limitations:

The USB standard provides a relatively small amount of power, which may not be enough to adequately power the audio interface's components, especially when using high-quality mic preamps or multiple channels simultaneously. 

Noise issues:

Power fluctuations from the computer's USB bus can introduce noise into the audio signal, particularly noticeable when using sensitive microphone inputs. 

Limited phantom power:

Many USB-only interfaces may not be able to provide enough phantom power to properly power condenser microphones. 

Headroom limitations:

When the interface is drawing near its power limit, the dynamic range of the audio signal can be compromised, potentially leading to clipping or distortion. 

Dependency on computer power:

If the computer is running on battery power, the USB power available to the audio interface can be further reduced, leading to performance issues. 

 

sadly, my wish to get the SSL 12 is what started me down this rao. But I have to pass. SoI am looking at the SSL 18, which is overkill for me and expensive.
The SSL 12 is $499 without discounts which Sweetwater and MF and other do regularly, especially for car holders and frequent buyers-like me and  many of you. 

Seriously thinking about the  SSL 18, especially since I can get a discount and pay it off no interest............................
Just venting.................

[Amberwolf]

1 hour ago, Pathfinder said:

Power limitations:

The USB standard provides a relatively small amount of power, which may not be enough to adequately power the audio interface's components, especially when using high-quality mic preamps or multiple channels simultaneously. 

(just some thoughts)

That depends on which version of USB and what the host supports.  

Newer versions USB3 can provide up to 30v and at least 100W, though those are normally only for charging ports.   But even for regular USB3.0 you can get up to 900mA (not quite double the 500mA of the original USB spec).   

Modern electronics doesn't take very much power to do a lot of stuff; depends on what's in there.  (less lights would be better for lower power usage; certain red leds are the lowest requirement).   As long as the device is designed correctly to work within the available power from a port, the port should be able to supply it. 

 

As long as the host device is correctly designed, and it's the only device powered by that port (no unpowered hub used to split the port to several usb-powered devices), power shouldn't be an issue.  (noise, etc, not covered by this, but the *power* should be clean if it's properly designed). 

If your interface can handle being on a hub, then using one with it's own correctly-deisgned power source would correclty supply the device with enough power to run.

That's all "theoretical" and "if properly designed" stuff--there's plenty of junk out there that isn't.... unfortunately that applies to things with wallwart power, too--I can't count the number of shitty wallwarts I swapped out on things to fix all sorts of annoying little problems .    

 

Phantom power; I could imagine that being an issue if the mics being used require a lot of current, but they shouldn't take too much.  I'd venture a guess at a dozen mA for a high average; I'm sure there are some that take more, but I don't know mics very well.   At 48v 10mA, that's  48 x 0.01 = 0.48watts.  For a regular old 5V USB port at 500mA, it has 2.5watts available, so that leaves about 2watts to run the rest of the interface.   So...depends on the whole interface design and the specific mic needs.   

 

Can't say anything experiential about powermanagement interference when running on batteries; I don't use my system that way (the battery is basically just a built-in UPS to me  ).  But remember that the port can't actually limit available power except by turning it off *completely*--it can't just turn down the amps available, because to do that it would have to turn the *voltage* down or PWM it; that's just how those things work. 

So if the system has powermanagement features that disable USB ports when on battery, turn those off and it won't be an issue.  If it doesn't let you turn them off...well, what else would you be powering the interface with, if you ahve to run the laptop/host on battery power, you don't have a plug to provide separate power for the interface either, right?

 

 

FWIW, I use an ancient Avid USB Duo (pro?) that's exclusively USB powered, and in all the years I've used it (and the M-audio version I used before that until a "friend" borrowed and lost it) Iv'e never had problems with it (taht couldn't be tracked down to driver issues, and few of those).   It's always plugged into it's own port directly on the computer (I don't recall my results using it with a powered hub).  It doesn't have any issue powering the generic mics I have (don't even remember if they have names on them :lol: ) but I don't do much mic recording; it's almost all cabled from the electric guitar or bass, or the pickup bar for the acoustic, or the "remote" from a lavalier mic (taht I sometimes use to record the various dogs' wierd noises for various fx use by clipping the mic to their collar, harness, etc).  

 

I did have problems with one backlit USB keyboard, a long time ago, which could not be set to it's max brightness or it would trigger the USB port power protection.    I had to use it on a powered USB hub to turn it up all the way, and the hub and it's power adapter always ran pretty toastily warm even though it was the only device on the hub.    

 

 

Sorry for the interruption.

[Amberwolf]

2 hours ago, Pathfinder said:

I so wanted the SSL 12 but refuse to not have an AC Power options.

forgot to add this:  a powered usb hub gives you the ac power option, or you can make or buy a y-cable USB taht sends the data and ground lines off to the computer but the power and ground to a usb wallwart capable of however much current you expect the device to need. (which you could base on the power supplied by the wallwart for the similar version that does have one).  

[mettelus]

+1 to the above, you will typically only see issues with power management on some "efficient" profile, or running on a laptop without it being plugged in. I only use desktops for connections, so cannot speak to the laptops much. As always, ground loops need to be considered.

I am, however, more curious about how you got from there to here? Initially it seemed your setup was fine, but you wanted the ability to monitor FX. Is that still the case or has that expanded? Also, how many channels do you record in one go? I have a similar setup to yours that I use most often (AI->PA system), but record only 2 channels of audio at most (vox and guitar) in one go. Unless you are recording multiple channels, the SSL 18 might be extreme overkill, and that is in the same price range as the HELIX Floor. The reason that caught my eye is the HELIX Floor also has a single mic input, and can be set up to record DI and FX channels for both guitar and vocals. Again, that may be extreme overkill for your situation (just to monitor FX but not record them). I may have missed a post where you explained more what you are seeking.