• WANTED: Happy members who like to discuss audio and other topics related to our interest. Desire to learn and share knowledge of science required. There are many reviews of audio hardware and expert members to help answer your questions. Click here to have your audio equipment measured for free!

Which USB out: laptop or dock USB jack?

ishouldbeking

Active Member
Joined
Oct 8, 2019
Messages
119
Likes
179
Location
DC-adjacent
After a recommendation on this site to consider using an Apple USB-C dongle as an external DAC (with a USB-C female to USB-A male adapter), I'm now curious if there's any reason to choose one USB output jack over another between the USB jacks on my thinkpad yoga vs the thinkpad onelink dock. I seem to recall reading that using a dock's USB jack might have some perceived benefit, although I've also read that dock jacks often don't shield as well as laptops, so I'm not entirely sure. I've tried both and seem to notice minor differences, but nowhere near as much as the difference between using the external dongle-DAC vs the laptop headphone jack, for example. Just curious if there's a standard recommended approach. Thanks, as always.
 

M00ndancer

Addicted to Fun and Learning
Forum Donor
Joined
Feb 4, 2019
Messages
719
Likes
728
Location
Sweden
I've tried both and seem to notice minor differences,
The difference you hear are in your head. Unless you do a proper blind test and can determine a difference. Don't worry. The only issue that I can think of is that the DAC and the dock wont co-operate every time you use it. Other than that use the USB that's most convenient.
 

Vincent Kars

Addicted to Fun and Learning
Technical Expert
Joined
Mar 1, 2016
Messages
781
Likes
1,555
You can have problems using specific ports e.g. ports might have a routing close to a switching voltage regulator.
Poor cabling, bad connectors (front side port) might cause problems too.
Simply try different ports and check if it does something for you.

Sometimes sharing an internal hub with a mouse or a bluetooth device might be audible.
If you move the mouse you will hear scratches in the audio.
In those cases you can use the device manager to find out if the DAC shares a hub with other devices.
http://www.thewelltemperedcomputer.com/HW/USB_Trouble.htm

However, this is about real technical problems like stuttering during playback, static noise, etc.
 

BillG

Major Contributor
Joined
Sep 12, 2018
Messages
1,699
Likes
2,266
Location
Auckland, New Zealand
Just curious if there's a standard recommended approach

I've no idea if this is standard, but I'd turn it on, not play any music through it, but turn my laptop and amp's volume all the way up to hear any noise it might generate. To establish a baseline, you might want to try that first without the DAC attached to hear if the amp generates any noise on its own normally, though.

If one USB port is noisy, simply switch to another that isn't... :cool:
 
OP
ishouldbeking

ishouldbeking

Active Member
Joined
Oct 8, 2019
Messages
119
Likes
179
Location
DC-adjacent
Thanks, all. The differences I was hearing could be placebo, but it was interesting because I was directly A/B/C/Ding between the two USB jacks and the headphone jacks on the laptop and dock respectively (i.e., taking the DAC dongle out of the chain). There were significant differences between DAC-dongle and the headphone jacks--particularly in the low end--but also some noticeable differences between the two headphone jacks. Between the two USB ports, it's not a huge difference at all and the volume is exactly the same--if anything, there seems to be a hair more clarity and separation between instruments when using the laptop's port. More noticeably, when using the port on the docking station, the USB-C adapter becomes noticeably warm (not disturbingly so, but it's distinctly warm to the touch); the laptop USB port doesn't seem to produce any heat. This might just be down to the fact that the docking station itself tends to run warm. Not sure if it's a sign of anything more nefarious, but I'll continue to experiment.
 

Ron Texas

Master Contributor
Joined
Jun 10, 2018
Messages
6,078
Likes
8,916
If they work at all they will sound the same. Some DAC's barf if connected to a hub, some work better.
 

trl

Major Contributor
King of Mods
Joined
Feb 28, 2018
Messages
1,967
Likes
2,523
Location
Iasi, RO
After a recommendation on this site to consider using an Apple USB-C dongle as an external DAC (with a USB-C female to USB-A male adapter), I'm now curious if there's any reason to choose one USB output jack over another between the USB jacks on my thinkpad yoga vs the thinkpad onelink dock. I seem to recall reading that using a dock's USB jack might have some perceived benefit, although I've also read that dock jacks often don't shield as well as laptops, so I'm not entirely sure. I've tried both and seem to notice minor differences, but nowhere near as much as the difference between using the external dongle-DAC vs the laptop headphone jack, for example. Just curious if there's a standard recommended approach. Thanks, as always.

Laptop’s USB ports have the lowest ripple & noise, so use laptop’s ports instead of dock’s.

However, there should be no audible differences between the two scenarios.
 

NTomokawa

Addicted to Fun and Learning
Forum Donor
Joined
Jan 14, 2019
Messages
779
Likes
1,334
Location
Canada
A USB hub/dock could introduce noise into your audio data stream. Whether it's audible is a whole other thing.

Perhaps the more important part is power. A (passive) hub or dock may not be able to supply the required power to drive your DAC. I know that's the case with my Steinberg USB interface.
 
OP
ishouldbeking

ishouldbeking

Active Member
Joined
Oct 8, 2019
Messages
119
Likes
179
Location
DC-adjacent
Interesting, and thanks to you both for the additional comments. As an update, I've been using Apple USB-C dongles for both my office and home setups for the past two months or so and have settled on different approaches for each location.

At work, where I have a ThinkPad Onelink+ docking station (which connects to my thinkpad using a proprietary "onelink" cable, which is capable of transferring data and powering the laptop with a single cable), I've settled on using the USB port on my laptop. At first I kept thinking I was noticing some sonic degradation due to elevated noise (edit: I was noticing some degree of perceived degradation when running out of the docking station), but I could never confirm it wasn't just placebo. But the reason I ultimately stopped using the USB ports on the docking station is that both the Apple dongle and the USB-C adapter I was using to plug it into a standard USB port were getting extremely hot when in use. Like, hot enough to make me worried. Both stay perfectly cool when running out of my laptop's USB ports, so I've taken to using those, even though it means I have to plug and unplug every time I take my laptop home. Such is life.

At home, I'm able to use my Anker USB docking station's USB ports with no issues. No audible noise, no issues with temperature. It's possible I'd get slightly better performance running directly out of the laptop, but the convenience of having everything plugged in and ready to go as soon as I dock my laptop makes it worth it for me.
 

vavan

Senior Member
Joined
Apr 29, 2019
Messages
341
Likes
212
Location
Kazan, Russia
A (passive) hub or dock may not be able to supply the required power to drive your DAC
but if DAC has its own power supply then even passive usb hub with lengthy cable may have no problems sending signal. for example I can output to two dacs simultaneously using 10 meter usb hub
 
Top Bottom