Drop Outs and "slip offs" in Audacity

Hello, folks!
My name is Chris, and I’m newbie in the forum.
Hope I can contribute here as much as i expect to find tips to solve a few puzzles that surface every now and again upon using Audacity, which I love very much!

Let me kick this off reporting a strange thing that has happening to my latest Audacity recordings. I’ll try to be the most specific that I can be, so please bear with me…

For starters, I have Audacity installed in all my lap-tops. I have versions 2.1.2 and the newest one 2.2.1 installed in different lap-tops, but only one version at each lap-top.

I’m facing some troubles with a Toshiba Satellite lap-top that runs vr. 2.1.2, Windows 7 Ultimate 64-Bit, with 4GB RAM that has never ever presented me any screw ups upon recording.

I have this lap-toppretty much as a main recorder-only function. It does not do anything else besides acting as a recorder, like a digital recording device.
So I have proceeded to do all of the tuning necessaries to make my Windows O.S. as stable as needed for flawless recording, which has worked as a pro since 2015 up until now with flawless recording sessions.

I use a Behringer UCA222 and UFO202 as USB recording interfaces. The UFO202 is employeed only when I’m digitizing vinyl records.

I’m a DJ, and I mainly use Audacity to record long set mixes, and also to digitize vinyl records.

My long set mixes last from 2 to 5 hrs. I use the UCA222 as USB interface, plugging the RCA cable that come sout from my controller plugged to the “IN” RCA slots of my UCA222, which ends up connected to my Toshiba lap top at one of the 4 USB free slots available.

While I’m recording nothing else is plugged into this lap-top.

My audacity configurations for recording are always 32-bit/48Khz, stereo, with the “update screen while recording or playing” turned off in order to reduce stress on the machine, and also the recording level tab turned off, as well. No software playthrough activated, too.

So my recording sessions goes like this: i click “record” and start playing and mixing my tracks. Whenever I screw up a mix, I press the “pause” button and go again at the same mix that I have previously screwed up. When I have the 2 songs ready at their respective poins to proceeed into the mix again, I press the “pause” button again and it resume recording at the same long and one-and-only track on the project. I wait 30 seconds after resuming the recording in order to reelase the tracks and proceed into the mix, again.

This has been the way I have always done, with no glitches at all. Of course, after the recording session is done, I proceed into post production and edit the heck out of it, cutting out all the unwanted parts and mending together the separated pieces, thus making it a long and continuous flawless set mix.

It’s important to point out that during the recording, upon hearing what was coming out from the speakers (the “OUT” RCA plugs from my UCA222 were connected to my amplifier, thus delivering the main out sound that came from the speakers so I could make the DJ mixing) no glitches or skips wre heard whatsoever. The skips or glithces only happened when I was listening to the recorded material.

THE PROBLEMS I HAVE BEEN FACING LATELY:

I have noticed a problem in one of the last recordings, made on december, 2017: after 1 hour of non-stop mixing, I have noticed a few skips at points of the recording material. It’s like the music is playing normal and then all of a sudden a beat comes way earlier than it was supposed to be, almost like if the track was cut/edited wrongly, at the wrong timing/tempo. At other points, it’s like the lyrics, vocal parts where cut wrongly, like if a split second of the song was abruptly taken out or edited out. This happened for the remainder of the recording, which lates 3:30hrs.

The skips started to happen after I started pausing the recording, upon my mixes were wrong and I had to interrupt the session to re-do the wrong passages/mixes, doing my explained procedure above of pausing and resume the recording at the same long track, giving it a 30 seconds window before releasing the music for recording.

This has never ever happened before. As a result, my post production editing session took a lot more time than usual, and I had to make some real miracles not to waste a long recording session, since this skips happened randomly, afecting some vocal/lyrics parts of sung tracks that I played in the mix.


ANOTHER PROBLEM THAT HAPPENED TO ME, LATELY: still intrigued with such “phenomenon”, I decided to record some previously recorded sessions that I had stored in Mini-Disc, that were in my plans to be “digitized” into files in my computer, so I could convert later to mp3 in order to make them available to post at different social media.

I wanted to make long recordings from those mini-discs into Audacity as a test to see if the problem happened again, so I simulated one long recording session for various mini-discs, and when one was finished (74 minutes) I paused Audacity to get another mini disc and put at the starting point to resume the recording session.

The first problem related above did not happen again, but and even stranger thing happened this time…

I was monitoring the recording session with headphones connected at the UCA222 headphone port, which is in fact a duplication of the “OUT” RCA plug connections from the interface.

After 3 hours recoridng almost non stop, only pausing to change mini-discs, and well into my 3rd MINI-DISC being recorded, all of a sudden I heard a glitch, as in total and complete abscence of sound for a micro second, in my headphones. When the recording session was over, I went immediately to Audacity to check the waveform at that point where the glitch has happened, and lo and behold tere was a skip (but in a different way than the skips previously related above) very clear and very visible in the waveform, upon using maginification.

Since I was able to hear the glitch happening in realtime thorugh my headphones, which in turn were conenected directly into my Behringer interface, I cannot assume at this point that it was a problem happening to Audacity, but rather either a problem happening to my UCA222, or a problem happening to my lap-top, more precisely at the USB port that I had the UCA222 plugged into (maybe lack of enough voltage? I doubt it).

Upon inspecting each and every one of my USB ports properties, I see they are all working properly and as they should, according to Windows, at the Device Manager.

So here’s what is going on with my latest recording sessions using Audacity.

I hope you guys could contribute and point out a few reasons for why this is happening, since I have never had any problems with glitches previoulsy, using the exact same equipments and configurations related in this post.

Thank you very much for enduring this very long post!

Hope you guys can lend a helping hand, here.

Kind regards from Brazil,
CHRIS

It sounds like it may be two separate issues.

Second one first:

That is almost certainly nothing to do with Audacity.

Question:
If you connect your equipment as described above, and do not launch Audacity or any other software, and then play a mini-disk, can you hear it in your headphones?

Hello! Thanks for the input!

Pardon me if I was a bit confused on my explanation…what I meant to say is that only Audacity is launched on my recording lap-top, thus making it possible to listen to what is coming from the mini-disc player through the headphones port in my UCA222.

When I’m in a recording session, the only application running in my recording lap-top is Audacity, and in “high priority” at the services tree.

Help me out, here!

I’m trying to.

If monitoring via headphones in your UCA222 is independent of Audacity (or any other software running on your computer), then we know that the problem you described as:
“all of a sudden I heard a glitch, as in total and complete abscence of sound for a micro second, in my headphones.”
is not a software issue.
That’s why I asked:

I still don’t know the answer to that because you haven’t told me, so I still don’t know if we are looking at a software issue or a hardware issue.

Thank you again.

I have never tested trying to listen to a mini-disc or any other line level equipment plugged into my UCA222 without Audacity or any other software launched. I’ll try to test this the next time I gather all the stuff together for a recording session, but my wild guess is that yes, it is very possible to listen through the headphones port of my UCA, provided the UCA is plugged into one of the the USB ports of my laptop. Since the UCA does not have an independent AC power connection, and it depends on the computer or laptop to have its energy supplied via USB connection, as long as it gets an energy source to function it can allow independent monitoring via its headphones port.

I expect that will be the case. If it is, then the most likely cause is a bad connection or a bad lead somewhere, and if that is the case, then that could be the cause of the other issue. I would certainly try to tackle this issue first. Visually check all of the leads, and give all of the connections a clean with electrical contact cleaner (though take care that some plastics can be affected by contact cleaner, so read the label carefully). Try giving the leads a gentle wiggle to see if you can cause the problem to happen. Leads or plugs with visible damage should be replaced.

That is a very interesting point you have raised, Steve.

Although the UCA222 that I’m using is like brand new, without a scratch mark on it. Not rusty signs on the USB contacts whatsoever, nor in the RCA connections.

For the first issue that I’ve related, one thing has come across my mind as a possible cause for those skips that have last throughout the remainder of that long recording session: you see, the UCA has a very long USB cable, and (I believe) in order to save space and package size, it comes from the factory with its cable fully folded, and that’s how I keep it stored when not in use - in its original package, inside a plastic bag with a silica gel little bag to prevent humidity.

Then, whenever i mount my gear up for a recording session, the UCA goes plugged in inside the laptop’s USB connection invariably with its cable folded, due to the folded package shape that the cable ended up taking form.

So one of the thoughts that crossed my mind is that this folded, zig-zag shape the cable presents might be a culprit in delaying the time the information being delivered to the UCA and later to Audacity in form of audio that’s playing in real time, hence causing this skips. Such skips results in lack of parts of the music, ultra small chunks of the track that don’t get recorded.

As for the second problem related, monitored through the headphone port in real time, it resulted in a hiatus, as in blank space in the wave form, so much so that it allowed me to correct such glitch by simply magnifying the area where this happened and simply mending together the 2 separate bits that came as a result, through highlighting the area in between with the empty space and deleting it. The 2 bits spliced together perfectly, which indicates that the original audio was recorded 100%, but with a break of silence right in the middle due to something that has caused it. It is important to note that no audio was missing in this second problem, but a blank space was inserted in the waveform, manifested acoustically by a glitch or a pause during the headphone monitoring.