Excessive latency is a common problem confronting the digital audio producer. The term refers to the delay between the creation of an audio event, such as an electric guitarist striking a chord, and its arrival at the output. By definition, every audio signal experiences a certain degree of latency; it is impossible to eliminate completely, but can be minimized to the point of being undetectable to the ear. AmpliTube, a comprehensive amplifier modeling plugin by IK Multimedia, tends, like most amplifier plugins, to be especially prone to latency issues. However, there are some strategies available to minimize its impact.
Connect your audio interface to your computer via the supplied USB cable. All of the most common interfaces on the market, with the exception of some very high-end devices, are USB devices.
Connect your electric guitar to your audio interface and turn the audio interface on.
Launch AmpliTube in stand-alone mode. Although it is possible to adjust the necessary parameter while in plugin mode within a host application, using stand-alone mode will help to identify the source of latency issues when using AmpliTube. AmpliTube will open and display its default interface. It should not be necessary to establish an audio input -- AmpliTube is designed to use the most likely source available.
Open the "Audio" menu and select "Hardware Settings." AmpliTube's "Hardware Settings" window will appear.
Open the "Buffer Size" drop-down menu and select a buffer size less than the default parameter of 144, but greater than the lowest option of 64. Although a buffer size of 144 should minimize latency on most present-day systems, some systems may still experience excessive latency depending on the hardware setup being used.
Play some notes on your guitar. If you are still experiencing excessive latency, reduce the buffer size parameter downward. Ideally, a lower buffer size should solve latency issues, but if the buffer is too small, the signal will begin to break up, a phenomenon called "artifacting." If reducing the buffer size does not work, leave the setting at the lowest point available before artifacting became an issue and close the "Hardware Settings" panel.
Close all applications on your computer you are not using. Amplifier modeling is a RAM- and CPU-intensive process -- freeing up as much RAM as possible often helps to mitigate latency significantly.
Play your guitar again to test for latency after closing all unnecessary applications. If excessive latency is still present, it is likely that the issue lies with your audio interface. However, upgrading your RAM to 2GB or above will sometimes solve the problem.
Make sure that any drivers or other software associated with your audio interface are updated to their most recent version. Occasionally, outdated drivers may conflict with the audio drivers or sound cards on your system. Download and install any updated drivers for your device from the manufacturer's website.
Minimize the virtual effects used in AmpliTube if the previous steps did not fix your latency problem. Unfortunately, this may be the only way to fix the problem, but should be used as a last resort because it limits your options when using the application. Effects such as heavy distortion, chorus and especially reverb are highly RAM- and CPU-intensive.
If none of the measures described here solve the problem, you may need to upgrade your hardware or try using a different audio interface. Latency can be a frustrating problem, but can be managed using these methods in the majority of cases.
Some audio interfaces include software through which their audio buffer can be adjusted. If your audio interface has this feature, reduce the audio buffer in increments and test for latency with each adjustment. This may also help with latency issues.