# Troubleshooting: Recording with USB turntables or cassette decks

From Audacity Development Manual

## Turntable not recognized by operating system

If the USB audio codec is not recognized in the Audacity Audio Setup Toolbar, you cannot record from it. If you connected the turntable while Audacity was already running, try Transport > Rescan Audio Devices or exit Audacity and relaunch it.

Make sure the turntable is plugged into the mains and switched on, and its USB cable is connected to the computer. Ensure you are plugging into a spare USB port, not a USB hub. Try a different USB port. Try using another USB cable - sometimes a faulty cable can cause this problem.

If that does not help follow, this sequence and reboot

1. Exit Audacity
2. Unplug all other USB devices (on Windows, use the "Safely Remove Hardware" icon in the System Tray)
3. Switch off and unplug the turntable at the USB connection and at the mains
4. Plug it back into the USB port, and switch it on
5. Wait a couple of minutes then completely shut down the computer and restart

When the computer has finished rebooting, open Audacity and see if the USB device is now in the Recording Device list.

If it is essential you run another USB device at the same time as the turntable and it is not already connected, connect it before connecting the USB Turntable, not afterwards.

If problems persist, request support from the turntable manufacturer.

## Recorded waveform is not centered on the horizontal line at 0.0

This is known as DC offset. It is less common with USB turntables or interfaces than with built-in sound cards. If offset is present, use Effect > Normalize to remove any DC offset before editing or exporting the recording. To do this, put a check mark in "Remove any DC offset" but leave "Normalize maximum amplitude" unchecked.

## White Noise

Sometimes "white noise" can smother the entire frequency range of the recording, or there can be other distortion. Remove the cartridge/headshell from the tonearm and reseat it tightly and securely. A loose cartridge is a known source of white noise. A poorly fitting or defective USB cable might also cause noise problems. Try a new USB cable and make sure both ends are tight.

## No signal in one stereo channel

The most likely explanation is a loose cartridge/headshell. Remove the cartridge and headshell from the tonearm completely and reseat it tightly and securely. A loose or defective USB cable can also cause this problem. Try using another cable.

## Recordings freeze up or have dropouts

Reports of recordings from USB turntables freezing or having dropouts are not that uncommon. Generally they are not caused by Audacity, but by poor quality equipment and cables, or lack of sufficient USB bandwidth.

- Check the Project Rate in Audio Settings Preferences is set to either 44100 or 48000 Hz - setting a very high rate might overload the USB bandwidth and cause transmission problems
- Check the USB cable for tightness at both ends and try using a different cable instead
- Always use a spare USB port, not a hub
- Limit USB bandwidth whilst recording by using other USB devices sparingly, for example simply disconnecting from the Internet may help if you use a USB modem for Internet access.
- Check for any system warnings (for example in Device Manager in Windows) about the Universal Serial Bus Controllers.
- There have been isolated reports that recordings freeze up if they are attempted whilst the unit's RCA cables are connected to an external input such as a home stereo, although concurrent recording and playing through external equipment is implied as being possible.

Generally, if you find you can record into Audacity without interruption from another source such as a microphone plugged into your computer's microphone port, this implicates the turntable or USB cable. To check if other sources record satisfactorily, change the Recording Device on the Audio Settings tab of Preferences to your inbuilt sound.

If recording from other sources works fine, try using the latest version of Audacity if you are not already doing so: it is possible very recent turntables might work better with the most modern Audacity version. Otherwise, request support from the turntable manufacturer.

If recordings from sources other than the turntable are also freezing or have dropouts, there could be problems with insufficient computer resources. If you are using "Enable audible input monitoring", it is also possible that problems with your inbuilt sound device (used to play back your recording while you are making it) are disrupting the recording.

## Speed too fast or slow or erratic

Note that some models of USB turntable, for example Numark/ION, have a variable pitch slider which allows the pitch to be increased or decreased by up to 10%. In the Numark model the pitch is unchanged when the slider is at central position. When the slider is moved away from the center and towards the tone arm the pitch is decreased (the platter is slowed down), and when the slider is moved away from the tone arm this increases the pitch (speeds up the platter.)

If the problem is one of fast speed, this can be due to a belt that is improperly installed. If the belt slips out of the groove when the turntable is rotating and is able to ride up or down on the spindle, the platter will spin too fast. You will need to adjust the position of the belt on the inner ring of the platter. The inner ring of the platter is quite a bit wider than the belt itself. The belt should wrap around the middle part of the inner ring. If it is wrapped too high or too low around the inner ring, it could cause the other half of the belt to ride up or down on the spindle. Follow these steps to check the belt for proper alignment:

1. Remove both the record and the slip mat from the turntable.
2. Rotate the platter so that you can see the brass motor spindle through one of the holes in the platter (it should be located in the bottom-left corner of the turntable).
3. Reposition the belt so that it is wrapped around the spindle's groove.

If adjusting the belt or any variable pitch slider does not help, please request support from the turntable manufacturer].

## Recordings too loud or soft

If the recordings are coming in at too high a level, so that they show clipping on the Recording Meter Toolbar, look for any control on the turntable that allows you to reduce its output volume. For example Ion and Numark models have a "gain knob" underneath the chassis that controls the output level. Be warned however that some users report that this gain knob does not work. Try to aim for a maximum peak of around \xe2\x80\x936.0 dB (or 0.5 if you have your meters set to linear rather than dB). Tip: enlarging the Meter Toolbar by clicking and dragging helps with this task.

Alternatively, you may find that the input level from the turntable is so low that the adjustment of the input slider on Audacity does not provide enough gain to get near -6 dB.

Windows: if adjusting the input slider on the Audacity Recording Meter does not help, try turning the input level up or down (as appropriate) in the system mixer - usually accessed on Windows by right-click over the speaker icon by the system clock and choosing Sounds, then click on the Recording tab, click on the USB device in the list and then and click on the Properties button, the click in the Levels tab, then turn down the input level for "USB Audio Codec".

For a more detailed walk-through of the above steps for Windows (or if that does not work for your version of Windows), see Windows: accessing the Windows Sound controls.

Mac: often provides no way to control the input level of USB devices, but to make sure, open Finder then use Go > Utilities and open Audio-MIDI Setup app. Select the USB Audio CODEC for the turntable then see if the volume slider is available to adjust the input level.

Additional solutions for excessive output volume:

- If you have multiple USB ports try a different port.
- If the cartridge is replaceable, take it to a hi-fi shop and see if you can get a lower output cartridge. If the cartridge is ceramic (cheap USB turntables often use these) it will have a high output. Replacing this with a magnetic cartridge will give lower output and better quality.
- If the turntable has RCA leads for connecting to speakers, plug the leads into an RCA stereo > 1/8 inch TRS adaptor (obtainable from any electrical retailer), then connect the adaptor to the line-in (blue) input of the computer. Set the phono/line switch of the turntable to line, and set Audacity to record from line-in. The input of the line-in can then be controlled using the Audacity input slider.
  - If your computer only has a microphone input, this input may be mono or may itself add excessive amplification. If the recording distorts due to excessive volume, you could try setting phone/line on the turntable to phono, but the recording may then sound "tinny" and lacking in bass because RIAA equalization has not been applied. To correct lack of RIAA equalization after recording, open Effect > Filter Curve EQ or Effect > Graphic EQ and apply the "RIAA" curve to the recording.

## Windows

### Stereo recording

External devices such as USB turntables usually default to mono recording on Windows Vista and later. This means that if you are recording a stereo LP into a stereo Audacity track, only one channel of the LP will be transferred, and this will be duplicated in both channels of the track. To record in stereo:

1. In Audacity, go to Audio Setup Toolbar, select "USB Audio Codec" in the "Recording Device" dropdown, and choose "2 (Stereo)" in the channels dropdown.
2. Right-click over the Speaker icon by the system clock, select Sounds, then the Recording tab.
3. Right-click over USB Audio Codec and hit Properties
4. On the "Advanced" tab, in the "Default Format" section, change the dropdown menu to "2 channel 16-bit 44,100 Hz"
5. If the input into Audacity is too loud or distorts, even when using the Audacity Input Level Slider, also click the "Levels" tab in "Sound" for the USB Audio Codec and move the slider to the left.

For a more detailed walk-through of the above steps for Windows (or if that does not work for your version of Windows), see Windows: accessing the Windows Sound controls.

### Microsoft Sound Mapper

There are some reports that Audacity does not detect the turntable input on Windows when "USB Audio Codec" is selected as "Recording Device" on the Audio I/O tab of Preferences. Try selecting "Microsoft Sound Mapper" in Preferences instead, making sure that "USB Audio Codec" is selected in the Recording tab of "Sound" in the Windows Control Panel. To access this tab, right-click over the Speaker icon by the system clock, select Sounds, then the Recording tab.

### Playback of recordings

If you experience difficulties playing back your recording in Audacity after you have made it, there could be problems with the drivers of your computer's sound device. These may not be fully up-to-date or compatible with your Windows version.