Samplers
This article provides some pointers for using samplers like Koala (or Loopy Pro itself) in Loopy Pro.
Common Issues and Solutions
- Not responding to MIDI (plugin idling). If a sampler is loaded in an Effect slot and there is no active incoming audio, the sampler may be idle (asleep). By default, Loopy Pro idles effects that are not receiving audio in order to save CPU. You can turn off automatic idling by opening the effect’s window and long-pressing where it says On or Off or Idle and turning off Enable Idle Mode. NOTE: this setting is global across all projects and will apply to this plugin in all projects.
- KOALA not responding to MIDI. First check to make sure that Koala is not idle. If it is idle, turn off the idling option (directions in the bullet point above). If Koala is not idle, open its window and close it. Koala sometimes does not respond to MIDI unless the window has been opened at least one time in the session.
- Plugin blocks monitoring. If you have the sampler as an insert effect on a channel strip that has monitoring on but you hear no sound, make sure that monitoring is turned on in the sampler. Some samplers (such as Koala and Loopy Pro) have settings that determine whether the sampler passes incoming audio out of the plugin.
- Plugin makes no sound when used as insert effect. If you are using a sampler as an input effect and triggering the sampler makes no sound, make sure that monitoring is turned on for the input channel. For example, if you have Koala Sampler loaded as an insert effect on the mic channel and the mic has monitoring turned off to avoid feedback, Koala’s output will not be audible when it is triggered because that channel’s monitoring is turned off. The solution is to use Koala on a bus. Set up a bus with Koala. Add a send from your input channel to the bus that has Koala.
Effects vs. Instrument
Samplers are sometimes used to play back pre-recorded sounds and sometimes they are used both record and play back audio. iOS has two basic types of audio plugins: effects and instruments. Instruments can play audio but cannot record; they have no access to audio input. Effects can both record audio and play back audio. Instruments and effects get loaded into different types of slots. This architecture is true of all hosts not just Loopy Pro.
| Koala Sampler loaded as an instrument. | Koala Sampler loaded as an insert effect |
Effects and Idling
Loopy Pro has a special feature called idling that reduces CPU usage when effects aren't active. By default, if an audio effect is receiving no audio input, Loopy Pro idles the plugin (puts it asleep). If you open the plugin window,

