A Tale of Two Channels - Stereo audio in UD-3900

I got a UD-3900 last year as a gift (it was on my Amazon wishlist). It’s pretty great!
I have revision B2.

I noticed on the box that it says it has stereo audio in using the 3.5 mm jack. I assume it’s a TRS jack, and under the device properties in Windows it shows it as a stereo input as well. I actually can’t change the channel, sample rate, etc, so I assume it’s stereo.

I wanted to play around with this, and got a Hosa YMM-261 to merge two mono microphones together into a single stereo input. But it looks like only the tip input goes through. Is the input actually mono?

Hi There,

Thank you so much for reaching out to us! I would be more than happy to answer your questions.

While TRS does technically support Stereo Microphones, it would have to be a non-split stereo microphone that is self powered, as only the Tip and Ring would be “activated” which means left and right channel. When utilizing a splitter and two single mono microphones, only a single microphone (As you have seen, the “Tip” or left channel") can be registered. This is different when utilizing a stereo microphone that has two channels or “pods” connected to a single 3.5MM.

In this case, the port is only Mono, based on the connected devices.

I hope this information helps, please feel free to let me know if you have any additional questions or concerns.

Thank you for your time,
Marc
Product Owner & Technical Support
www.plugable.com/support

Thanks for the quick response!

That’s interesting. I had thought that using the breakout cable would effectively make the two microphones be detected as a single stereo microphone, where the tip would register on the left channel and ring on the right, as expected. At least, that’s how the page describing the YMM-261 said it would work!

Something I’m not completely clear about is: is it an issue of power? That is, the port can’t power two microphones connected to the splitter? You mentioned that a single stereo microphone with a single cable would work. But by “self powered” do you mean that it is getting its power from some external source? Or would the TRS cable be enough in that case?

If the TRS cable works, then I assume splicing the microphones I have *might* work if they don’t require more power than the jack can provide. Am I on the right track here?

edit: this is the page where I learned about the breakout cable: https://www.thepodcasthost.com/equipm…. They’re connecting it to a Zoom H5, which I’m guessing is able to provide enough power? I’m not podcasting or anything, nor am I using those microphones in the link. Just experimenting!

Hi There,

Based on the information that we know regarding the port itself, and its ability to utilize connected stereo microphones, it is an issue related to power, and splitting. The port is Mono, but not when a single 3.5mm Stereo microphone is connected. This way the TRS can read both the “Tip” and “Ring” left and right side channels, but if two separate connections are made, using a splitter, then the 3.5mm TRS connection may not have enough power to route to two separate devices. We would not advise attempting to cut or splice the two devices together, but purchasing a stereo microphone that is routed through a single 3.5mm connection may be the best route to experiment with!

I hope this information helps, please let me know if you have any additional questions or concerns.

Thank you for your time,
Marc
Product Owner & Technical Support
www.plugable.com/support

Hi Everyone,

We were able to provide some information regarding compatibility of stereo microphones, and other information about the audio ports on our docking stations for Alok. We hope he was able to utilize this information to match his intended configuration, and would be happy to help with anything else if it is needed!

If anyone else has any additional questions or concerns, please feel free to reach out to us directly at support@plugable.com, and we would be more than happy to assist!

Thank you for your patience,
Marc
Product Owner & Technical Support
www.plugable.com/support