I have a Behringer UCA-202 USB audio interface that I used to use to rip music from vinyl and tapes on Windows using Audacity.
I am in the process of getting rid of Windows, and moving to Linux 100%.
I set up Audacity on Ubuntu and tried recording a vinyl LP, but I found that the recording level could not be adjusted. The rec level slider can move, but the level does not change. The peak levels being recorded are less than 50% of the vu meter range.
I don’t think that there’s a problem with the interface. Audacity on Windows (using the default MME interface) is able to control the input level, and it has to be set low in order to keep from overdriving.
Is this a device driver limitation? Would switching to pulse or jack to manage the audio input make a difference?
If there’s a workaround to control the input level of the UCA-202, please pass the word. I have several albums that I’d like to convert to digital, and I’d like to get the setup working well.
I use a separate phono preamp. The UCA-202 is connected to my receiver’s REC OUT jacks.
Note that in my post, I mention that the output level too low issue only occurs with Audacity on Linux. There’s plenty of drive with the same hardware running Audacity on Windows.
On Linux:
By default, there will be no gain (no amplification) applied to the input from the UCA-202. The signal received by Audacity will be at the same level as output from the ADC (analog to digital converter).
I have a UCA-202 and I’ve just tested this.
It is “possible” to override this default behaviour, but there is little benefit in doing so.
“PulseAudio” (the default sound system for Ubuntu) may be configured to boost the signal from the UCA-202, but note that this boost occurs after the conversion from analog to digital. In other words, it is exactly the same as applying “Amplify” in Audacity.
The advantage of sticking with the default (no scaling) is that you can see the actual signal level coming from the DAC.
On Windows:
I’m not able to test this right now, but as an educated guess, Windows is probably boosting the level from the DAC (scaling the digital signal), which again is the same as applying “Amplify” in Audacity. This is common default behaviour on Windows when using USB devices.
Is it possible to increase the output level from the pre-amp? This would be the ideal solution as it occurs before the signal is converted to digital.
If that is not possible, then I’d recommend just using the Amplify (or “Normalize”) effect after recording.
Thanks for looking into this Steve.
My phono preamp does not have adjustable output. It’s a basic PP400, but that’s all I needed.
Perhaps I have old fashioned thinking (from recording to tape), but the advice I have followed for many years is to nudge the recording level to the point where the VU meters bump the red zone during the peak output levels. Is this no longer relevant? Under Linux the rec level can’t be changed, and it typically tops out around -42 dB.
I suspected that the UCA-202’s audio codec had provided adjustable gain control via USB, and that (since Windows gets the full support of device manufacturers) that this allowed the MME interface in Audacity to control the recording level. However, I see that it’s also possible that Windows is taking the audio stream and applying a normalization filter per your description.
I tried an experiment just now, I swapped out the UCA-202 for a Yamaha AG 03 mixer. Since it has output controls I thought it might be able to boost the output further, but that turned out to be incorrect. It can reduce the amplitude of the line level signal, but it doesn’t go beyond 100% of the input level.
So it’s not unusual to settle for 30%-ish of the total amplitude displayed in Audacity when recording?
With digital audio it is essential to remain below 0 dB.
When recording in digital, it’s good to aim for a maximum peak level of around -6 dB. A bit above or below is fine, but always below 0 dB or permanent “clipping” damage occurs.
In professional studios with high end equipment, it is common to record with a peak level of around -20 dB, but for consumer or semi-pro equipment a bit higher is recommended (ideally around -6 dB).
That is definitely lower than ideal.
Are you able to test with a different audio source (line level)? For example, connect the outputs of a CD player to (ideally a hi-fi CD deck)?
I rummaged through my parts bin and found two old/cheap USB sound cards.
I tested both of them using the same audio input (receiver REC OUT from preamplified turntable).
For the record, this receiver has multiple sources (tuner, wifi stream, CD player, etc.) and the output levels are consistent.
Swapping out the UCA-202 for either of these cards changes the problem from under-driving Audacity’s input level, to overdriving it. The waveform pushes well above 0 dB.
If the level could be adjusted, I’d be all set. The mic level slider in Audacity is pegged to the top level and inoperable. At first glance the sound cards don’t seem to have adjustable input level, but I need to look them up to confirm it.
I’m closer to having a solution now than I was with the underdriving situation. I’ll take this offline and see what a few searches turn up.
I think those interfaces are designed for microphone input.
The signal level from a mic is tiny - MUCH lower than “line level”, hence the large amount of “gain” (amplification) prior to the ADC.
The inputs of the UCA-202 are designed for “line level” (Line level - Wikipedia), which is approximately 0.5 V peak (max).
The phono pre-amp “should” be outputting close to that level. Can you think of any way, using the equipment that you have access to, to test the output from the phono pre-amp? It should be roughly similar to the output from a cassette player “AUX” output.
Open the Ubuntu “Audio Mixer” and select the “Input Devices” tab. I’ve highlighted the input level control of the UCA-202.
Shown below, the level is “100%” (default).
As well as boosting the signal level, a phono pre-amp also applies RIAA equalization that boosts the bass and reduces the level by precise amounts (RIAA equalization - Wikipedia).
I have the ARTcessories pre-amp that I used connected to my Edirol UA-1EX from my turntable. build quality and sound quality is excellent. They didn’t make this integrated pre-amp/USB sound card at the time I was buying - had they done so I almost certainly would have bought one.
Thanks for the help all. I have it working satisfactorily now.
It occurred to me later yesterday that the extra boost that was coming from the USB sound cards was coming from the mic level inputs. Duh!
Thanks for pointing that out.
I went back to using the UCA202 and connected an old equalizer to my receiver that has its own set of REC OUT connectors. It provides the option to “EQ recording” with level control. I left the equalization flat, but the level control allowed me to boost the signal to the UCA202 enough for Audacity.
Also thanks for pointing out that the pavucontrol input devices tab allows the UCA202 CODEC to be level adjusted, as an alternative to the Audacity level control. That is a big help for fine tuning the recording from one vinyl record to the next!
