Behringer UCA202


I have just recorded a DJ mix using this interface with Audacity.

I have RCA leads from my mixer to the Input L and R on the Behringer. Then this is connected to my iMac via USB.

When listening back to the recording i get a faint high pitched whistle throughout ???

Can anyone advise why ?

Are my connections correct ? Do I have to change settings in Audacity ?

Thanks in advance

Does it still whistle if you listen to the iMac headphone out with the UCA202 disconnected?
It’s a home run between the UCA202 and the iMac, right? No hubs?
Does it whistle if you switch the UCA202 to Monitor and listen at the headphone connection during the recording? Or stop playing for a second and listen for it.

Yeah no hubs. Have tried everything but I’m still getting the faint high pitched whistle. Very frustrating.

The monitor switch on the UCA202 should be off right ?

The Line-Out and the Headphone Out have the same show. All Monitor does is provide a way of listening to Line-In and Line-Out at the same time as a mix. This would seem to be of limited usefulness, but it’s required to do Overdubbing and Sound-On-Sound.

It’s also handy if you’re having troubles. Turn it on and listen to your system at the UCA202 headphone connection with no music. Does it whistle?


Just tried this. It does whistle when monitor switched to On but not if I switch monitor to off ???

By the way my speakers are connected to mixer not the output on UCA202.

That means the mixer feed to the UCA202 is whistling.

Time to get specific. Which mixer? Where is the UCA202 feed coming from? Tape-Out? Can you get it from somewhere else, like temporarily jack into the mixer headphone feed?


Mixer is a Pioneer DJM250

I am connecting the UCA202 via the Master 2 inputs.

Actually, it’s the Master-2 Outputs. The mixer has two sets of outputs. The broadcast balanced (3-pin XLR) and the home music RCAs.

Thank you for the complete information.

This is where I would be dragging out test equipment which you can’t do.


Wait. How are the speakers connected to the mixer and do the speakers have a volume control? Model numbers?


I am using KRK Rokit 5’s and they are connected to mixer XLR to jack

and yes they have a volume control

I am using KRK Rokit 5’s and they are connected to mixer XLR to jack

My Roket5s have an XLR on the back. Is that what you’re using? Standard XLR Male to XLR Female also known as a “mic cable.”

That’s too bad. That’s pretty much what you’re supposed to be doing.

I’m close to being stumped. You can hear the whistle at the UCA202 headphone point switched to Monitor, but the Roket speakers are silent?

The Rokets also have an RCA on the back. Can you disconnect and move one of the Rokets to listen to the UCA202 Line-Out (in Monitor)? That whistles, right? And if you move that Roket to the mixer out it’s silent?

You may have the only broken UCA202 we’ve ever seen. I might try a different iMac USB connection.

We have a large number of these things in service and have never experienced a failure. I keep thinking there’s something else wrong and we just haven’t found it yet.


I am using Serato by the way.

I’m totally stumped

This is a screenshot of my settings in Audacity

This is correct right ?

As far as I know.
Can you make it worse and does it ever change pitch?
What happens if you don’t run Serato and just make a straight recording from, say, the microphone?
Post a sample of the sound here.

You’re using the UCA202 because your iMac has no Stereo Line-In, right? You’re missing one of these connections?


Yes I am using the UCA202 due to no Stereo line in on my new iMac

I’m not sure where to go with this. Post some of the sound.