Virtual Audio Cable is a Windows multimedia driver allowing you to transfer audio (wave) streams from one application to another. It creates a pair of Wave In/Out devices for each cable. Any application can send audio stream to Out device, and any other application can receive this stream from In device. All transfers are made digitally, providing NO sound quality loss. VAC is a "wave-version" of the "MIDI loopback cable" like MultiMid or Hubi's Loopback drivers.

If more than one applications are sending audio to VAC, it will mix all streams together. If more than one applications are receiving audio from VAC, it will share the same audio data between all targets.

VAC is useful to record application's audio output in real time (for example - Generator, Reality or other software synth), or transfer a sound stream to another application processing it. You can, for example, use two or more software audio generators/synthesizers/sequencers to produce audio streams sending them to VAC Out, and record the mixed stream from VAC In using any recording software - Windows Sound Recorder, Sound Forge, WaveLab, Cool Edit, Gold Wave, Cakewalk, Cubase etc.

Changes in v4.12

• Bugfix for RtAudio buffer processing bug in Audio Repeater KS.
• Clock rate display added to Audio Repeater.
• Changed number of worker threads limit to a number of logical CPUs.

Changes in v4.11

• Added cable multi-selection feature to Control Panel.
• Clock correction precision increased to 0.0000001% (1E-8%).
• Added volume boost feature.
• Bugfix for sampling rate change bug causing incorrect playback speed.
• Rewritten data processing code from DPC to system thread set to minimize interlocked waiting and improve performance on multi-CPU/core systems.
• Stream buffer watermark control feature added to improve stream stability.
• Added "Reset counters" buttons (Control Panel) to reset cable/driver counters.
• Minimum possible sampling rate increased from 200 to 1000.
• Optimized KS Audio Repeater algorithms for more reliable transfer.
• New feature of Audio Repeater: now command-line options can specify device number
• Added several channel mixing/distribution schemes.
• Added channel scatter/gather mode and cable channel mixing control.
• Increased clock correction precision (registry value format is changed).
• Added a privilege elevation manifest to Setup application to elevate privileges automatically.
• Maximum sampling rate changed from 1000000 to 384000 in accordance with MS requirements.
• Add "already installed" warning to Setup application.
• Bugfix for bug in KS Audio Repeater (device name string length was limited to 31 chars as in MME version).
• Bugfix for some node property errors.
• Bugfix for some minor bugs.