Eliminating Clicks, Pops, and Distortion
OASYS PCI Website
Contents
Check word clock settings
Incorrect word clock source settings are by far the most common cause of digital audio clicks, pops, and distortion. Make sure that the word clock source of each connected digital audio device is set correctly. For more information on word clock settings for common setups, see OASYS PCI System Setups.
Make sure that your computer is optimized for audio &
MIDI
Many seemingly innocuous features can cause problems with digital audio and MIDI programs. Such problems can result in audio pops and clicks, or even audio dropouts. Fortunately, these problems can be avoided by careful configuration of the MacOS or Windows system to ensure reliable audio performance. For more information, see:
Optimizing MacOS for audio and MIDI
Optimizing Windows for audio and MIDI
Check all cables, analog and digital
Check that cables are fully inserted and seated securely
If cables are not fully inserted and seated securely in their jacks, they may not work properly (or at all). This can cause audio problems, such as clicks and pops, or complete silence. Note that cables can sometimes work loose from their connections for various reasons - so check the cables even if the setup was working previously.
To make sure that cables are seated securely, disconnect and re-connect them. Make sure to also check the OASYS PCI analog and digital breakout cables, and their connections to the OASYS PCI card. In particular, take care to fully insert the OASYS PCI analog breakout cable into the connector on the card, pressing gently but firmly until it is securely seated.
Swap out cables
If problems persist, it is possible that a cable has become damaged (as cables have been known to do). If possible, try swapping out suspect cables - preferably, using cables that you know are working properly.
Throw away Preferences files (MacOS)
Sometimes, preferences files (usually stored in the System:Preferences folder) can become corrupted. If you encounter persistent problems with digital audio programs, try dragging the program's preferences file to the trash. In some cases, it may also be helpful to throw away the OASYS PCI's preferences files, and the Sound Manager preferences file (even if the problem doesn't seem to involve the Sound Manager).
The OASYS PCI and the Sound Manager both store their preferences files in the System:Preferences folder. The OASYS PCI has two preferences files, named OASYS PCI Driver Preferences and OASYS PCI Editor Preferences; the Sound Manager's file is named Sound Preferences. For information on the preferences files used by digital audio applications, please see the program's documentation.
After throwing away the Preferences files, restart the computer.
Toggle clock source or audio hardware
selection
Sometimes, the software connection between the digital audio software and the OASYS PCI may become disrupted. To re-establish the connection, try toggling the OASYS PCI word clock source (in your audio/MIDI program, OASYS PCI Editor, Wave Device settings etc.), or selecting another audio hardware option in your audio program (such as Sound Manager, MIDI Only, etc.) and then switching back to the OASYS PCI.
Increase Audio Buffer Size
Smaller Audio Buffer Size settings allow you to decrease CPU input-to-output latency, at the expense of slightly higher CPU loading. Depending on the speed of the CPU, the amount of host-based plug-ins you are running, the speed of the audio disk, and other factors, some computers may require higher Audio Buffer Size settings than others. You may need to experiment to find the best setting for your system.
You can set the Audio Buffer Size in the ASIO Control Panel, or in the OASYS PCI Editor's Audio Settings dialog. After changing this setting, you'll need to reboot before using the OASYS PCI.
NOTE: The Audio Buffer Size affects only the CPU input-to-output latency - the amount of time that it takes to route audio from the OASYS PCI inputs, through a CPU-based digital audio program (and that program's CPU-based realtime effects), back to the OASYS PCI outputs.
DSP input-to-output latency - the amount of time that it takes to trigger notes when playing OASYS PCI synths, or to route live audio inputs through OASYS PCI effects - is unaffected by the Audio Buffer Size.
Disable Monitor Mixer (version 1.0 only)
When using OASYS PCI software version 1.0, the Zero Latency Monitor Mixer may sometimes cause pops and clicks.
This has been fixed in software version 2.0.
If you are using version 1.0, and have already tried the steps detailed above but still hear pops and clicks, try disabling the Monitor Mixer. You can do this by clicking on the button next to the text "Zero Latency Monitor Mixer" in the top-right corner of the ASIO Control Panel or Audio Settings window. When the button's light is turned off, the Monitor Mixer is disabled.
Copyright 1999-2002 Korg Inc. FAQ Version: 8/19/02