Virtual Audio Cable

With Virtual Audio Cable (VAC) free software, you can connect Windows PC audio applications together, routing audio signals between them. You definitely know that traditional hardware audio devices (CD/LP player, FM receiver, equalizer tool, amplifier, etc.) may be connected together by electric (analog or digital) cables. VAC provides a set of virtual audio devices named Virtual Cables. The "Virtual Cable" term is used only in the VAC description, actual device/endpoint names are different.

You could create the same path, connecting the analog output of any audio adapter (sound card) to its own analog input by a plain electric cable. Then, you can select playback and recording endpoints in source and destination applications, so they become connected to each other. VAC performs such signal transfer completely inside the computer, with no audio hardware, and with no quality loss (if no format conversion and/or volume control are involved). Download Virtual Audio Cable for Windows PC now!

However, the digital audio signal produced by the source application will come through a digital-to-analog converter, then through the electric cable, then through an analog-to-digital converter, and finally recorded by the destination application. Therefore, double digital-to-analog and analog-to-digital conversions are performed in case of such connection, and audio quality is degraded.

VAC behavior is similar to the "Stereo Mix" ("What You Hear" or "What U Hear") feature of some hardware audio adapters (cards). But it is only similar, not equivalent. If you simply need a function like "Stereo Mix" under Vista/Win7/Win8/Win10, there could be better to try to enable it in your audio adapter.

No audio hardware required
You need no audio hardware (sound adapter/card), either built-in or external, to use VAC for digital audio transfer. Audio hardware is required only to hear the results, or to record signals from external sources. On a computer with no audio adapter (card), you still can use VAC to record audio signals produced by applications (for example, testing audio broadcast on a virtual server).

Control panel application
VAC Control Panel application allows you to change the number of Virtual Cables, view/modify VAC driver and cable settings, watch for cable/stream activity.

Device-to-device audio transfer
Virtual Cable devices (endpoints) allow you to organize application-to-application audio transfer only. To perform the endpoint-to-endpoint transfer, use the Audio Repeater application included in the product package.

Driver-based solution
VAC contains Windows WDM/KS virtual device driver that creates virtual audio devices. This driver is a kernel-mode module and needs to be installed with administrator rights. Being a WDM/KS filter, VAC represents the lowest-level audio layer in Windows. It can be effectively used by any upper-level layer (KS-aware applications, WASAPI, MME or DirectSound subsystems, ASIO wrappers, and so on).

Comprehensive user manual
VAC user manual is included in the free trial package available on the download page. It contains many details useful for a better understanding of the product and using it correctly. You don't have to install the trial version to open and read the user manual. Just download the ZIP archive, open it to see the contents, and double-click on the file named "vac" marked by the question mark icon (the "chm" extension).

Features and Highlights

• Windows 11, 10, 8.1, 8, 7, Vista, and XP platforms (32-bit and 64-bit).
• Up to 256 Virtual Cables, allowing to transfer up to 256 independent audio signals at the same time.
• Latency can be reduced down to 0.5 milliseconds.
• Almost any of fixed point PCM audio formats (1000..384000 samples per second, 8..32 bits per sample, 1..32 channels).
• PCM format conversion (sampling rate, bits per sample, number of channels).
• RT Audio (WaveRT) protocol support with notification events, packet mode, clock, and position registers. Clock registers are bound to Virtual Cables so all streams in each cable are coherent.
• An unlimited number of Kernel Streaming clients. You can share each Virtual Cable between any number of KS-aware audio applications or ASIO wrappers.
• Signal mixing from all streams of each Virtual Cable, allowing to mix signals from several applications in real-time.
• Volume control features (both attenuation and boost).
• Channel scattering/gathering mode. Using KS-aware applications, you can map particular channels in a stream.

Note: Limited functionality in demo version.