AVR to SOU Converter

Transform Audio Visual Research AVR into SBStudio SOU

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Retro Platform Bridge

Connect two vintage computing worlds — convert Atari ST AVR recordings into SOU for other retro platform projects.

No Emulator Required

Convert AVR files without an Atari ST emulator or SoX command line. The entire process runs in your web browser.

Secure Processing

Uploaded AVR files are deleted immediately after conversion. Output files are purged within 24 hours.

How to convert AVR to SOU

1

Select files from Computer, Google Drive, Dropbox, URL or by dragging it on the page.

2

Choose sou or any other format you need as a result (more than 200 formats supported)

3

Let the file convert and you can download your sou file right afterwards

About formats

AVR (Audio Visual Research) is an audio format that originated on the Apple Macintosh around 1989, created by the Audio Visual Research company for their editing and synthesis tools. It stores raw audio samples preceded by a fixed-length header containing sample rate, bit depth (8 or 16 bits), channel configuration, and loop point markers. Unlike complex container formats, AVR uses a flat binary structure with no compression, preserving the full waveform quality at the expense of larger files. The format served professional Macintosh audio workstations during the late 1980s and early 1990s, when the Mac platform dominated creative computing. One advantage is uncompressed storage guaranteeing zero artifacts and perfect signal integrity through editing operations. Native loop markers represent another feature, letting sound designers define seamless repetition points within the file — ahead of its time for sample-based music production. Tools like SoX maintain AVR support, ensuring archivists can access and convert these legacy recordings. While eclipsed by WAV and AIFF, AVR remains a notable piece of early digital audio history.
Initial release: 1989
SOU is a raw audio format designation that functions as an alias for unsigned 8-bit PCM data (u8) in the SoX audio processing framework. Files with the .sou extension contain headerless, uncompressed audio samples stored as unsigned 8-bit integers — each byte represents a single amplitude value from 0 to 255, with 128 as the silence midpoint. Because there is no header, playback parameters such as sample rate and channel count must be specified externally. The default assumption is typically mono at 8000 Hz, though the data can represent any rate the recording hardware supported. The u8 encoding that SOU aliases is one of the simplest possible digital audio representations, predating structured audio containers like WAV and AIFF. Raw unsigned PCM was commonly produced by early sound cards and digitizers in the late 1980s and early 1990s, when storage constraints and limited processing power made headerless formats a practical choice. One advantage is absolute simplicity: SOU files can be read by any program capable of basic file I/O, with no parsing of container structures or metadata decoding required — useful for embedded systems, hardware diagnostics, and educational contexts where audio fundamentals are being explored. The format's minimal overhead also means that conversion to any modern container is lossless and instantaneous, since the raw PCM samples can be wrapped in a WAV or AIFF header without any transcoding.
Developer: SoX Contributors
Initial release: 1991

Frequently Asked Questions

Why convert AVR to SOU?

SOU is the SBStudio II format. Converting AVR to SOU connects research audio with the Creative Labs editing ecosystem.

What can open SOU files?

SBStudio II and SoX handle SOU files.

What is the AVR format?

AVR (Audio Visual Research) is an audio format developed for the Atari ST computer. It was used in academic and research audio applications.

Is AVR widely supported today?

AVR is a niche legacy format. SoX and Audacity can read it on modern systems, but mainstream media players do not support it.

Can I convert multiple AVR files at once?

Yes. Upload several AVR recordings and batch-convert them all simultaneously — efficient for processing research audio libraries.