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5. FAQ (Frequently Asked Questions)

5.1 Features

What are the supported audio file formats?

For both reading and writing:

  • Formats: WAVE (*.wav), AIFF/AIFC (*.aiff/*.aifc) and AU Sun/NeXT (*.au).
  • Encodings: 16-bit (signed integer, PCM), 24-bit (signed integer, PCM) and 32-bit float* (PCM)
    • *For 32-bit, only IEEE float encoding with sample values normalized to the -1.0 - 1.0 range is supported (known as type 3 for WAVE files); other 32-bit encodings (32-bit signed integer, or float in the +/- 32768 range) are not supported.
    • Compressed encodings within WAVE, AIFF/AIFC or AU files are not supported.
  • Audio files of more than 4 GB are supported in the WAVE format, using the "RF64" extension, and in the AU format.

For reading only: MP3, FLAC, OGG, OPUS, M4A (AAC and ALAC). Tachyon might not recognize multi-channel or high sample rate audio files in these formats.

Warning: the AU file format used by Tachyon (also known as Sun/NeXT audio, SND, or "basic audio") is unrelated and not compatible with the *.au files used internally by the Audacity free editor, although they use the same file extension. Audacity can both load and export audio files in the AU format used by Tachyon though.

Does Tachyon support surround and 5.1 multi-channel audio files?

Yes. Tachyon supports mono, stereo and multi-channel files (including 5.1 and 7.1) as long as the individual channels correspond to stereo/spatial information (and not to different "tracks"), and as long as there is enough memory.

If the channels correspond to different "tracks" (such as vocal, bass, etc), it is preferable to split the tracks into individual files and to transform them separately. The reason is that Tachyon locks the phase of all channels of a multi-channel file in order to preserve the stereo (or spatial) field. Locking the phase between unrelated tracks on the other hand might result in a deterioration of the quality, which is why unrelated tracks should be transformed individually - using separate files. If a given track is stereo, it should be extracted into a stereo file rather than in two mono files.

Warnings:

  • Tachyon does not preserve meta-data related to channel/speaker configurations of multi-channel audio files.
  • Surround formats that "pack" more than two virtual channels into a stereo file (such as Dolby Surround or Dolby Prologic) might work but this has not been tested.

What are the supported sample rates and bit depths?

  • Sample rate: from 8 kHz to 384 kHz.
  • Bit depth: 16-bit (signed PCM), 24-bit (signed PCM) and 32-bit IEEE float (with samples between -1.0 and 1.0 - type 3 for the WAVE format). The 32-bit float format is always used internally.

The available memory, the quality setting and the number of channels might limit the maximum sample rate. The 32-bit version of the application for instance cannot transform 384 kHz, 5.1 audio files with the maximum quality setting.

What is the maximum time stretching ratio?

The maximum is 4 times slower or 4 times faster.

Note that within the application, the slider (see (1) in the figure below) only allows you to choose from 2 times slower to 2 times faster (which is the recommended range). You must type a value directly in the number field (2) next to the slider to choose a higher ratio up to the maximum. Transforming more than 2 times slower or faster might result in lower quality.

Time stretching ratio: slider and number field.
What is the maximum duration of an audio file that can be transformed?

There is no limitation as long as you have enough disk space and enough processing time. Tachyon has been tested with audio files of several hours of duration, and might be able to process even longer files.

There are a few caveats though:

  • The AIFF/AIFC (*.aiff, *.aifc) file formats do not allow files of more than 2 GB. You must save them in the WAVE (*.wav) or AU (*.au) format. Tachyon will ask you to change to the WAVE (*.wav) format if an AIFF/AIFC file would get larger than 2 GB.
    • See Section 3.2.3 to change the output file format before starting the transformation.
  • Some applications may not support reading WAVE files of more than 4 GB or AU files of more than 2 GB. For WAVE files of more than 4 GB, Tachyon automatically uses the "RF64" extended format.
  • You must have enough disk space for the sum of the sizes of:
    • the input file,
    • the temporary output file (always in 32-bit float raw format) - see Section 4.3.2 to change the location of temporary output files,
    • the output file in the specified target format (can be 16, 24 or 32-bit) - see Section 3.2.3 to change the location of output files.
  • The Mini Player (see Section 4.1) can be slow when seeking into input files of long duration. You may want to use your favorite audio player instead.

Does Tachyon dither the transformed files?

No. However, you can save in a 24-bit or 32-bit format (see Section 3.2.3 ) and apply dithering afterwards using your favorite DAW.

How accurately is the time stretching ratio honored?

Tachyon is accurate up to a single sample (and is in fact sub-sample accurate internally) even with audio files of more than one hour, as long as the quality is set to 3 or to 4 (maximum and default setting). With lower quality settings, the result can drift from a few samples.

Even if the time stretching ratio is displayed as rounded in some parts of the user interface, the exact entered value is remembered and used, up to the 10th decimal point.

How much time does it take to time-stretch a file?

This depends on many factors. Using a 44.1 kHz stereo file, it generally takes about 5 - 10 minutes to produce 1 minute of audio on a 3 Ghz processor using the default maximum quality setting. It might take even longer when speeding up, because in that case the time is proportional to the duration of the original file and not to the duration of the transformed file.

  • Transforming audio files with more (or less) channels takes proportionally more (respectively less) time, approximately.
  • Transforming audio files with a higher (or lower) sampling rate takes proportionally more (respectively less) time.
  • Transforming a 16-bit, 24-bit or 32-bit float audio file takes the same time (bit depth, or resolution, has no impact on processing speed).
  • Using quality 3 instead of 4 (maximum) is generally at least twice as fast, and virtually indistinguishable from the maximum quality 95% of the time (as long as you do not change the crisp/smooth setting). See section 3.2.2 to change the processing quality.
  • On a multi-core system, multiple files can be transformed simultaneously, saving some time. See section 4.3.2 to change multi-core settings (number of processing threads).

Can Tachyon process audio files in real-time?

No, it generally cannot, and real-time is in fact not a design goal. Tachyon is designed to achieve the best possible quality, and hence is targeted to off-line processing only.

In practice you might achieve real-time processing speed with the minimum quality of 1, and even with quality 2 (maximum is 4) on a sufficiently fast processor. Processing is always done off-line though, and on-the-fly processing during playback is not supported. However, it is possible to play partially processed files using the integrated Mini Player (see section 4.1).

Note

By real-time processing, we mean that time stretching a given duration of audio takes less time than that duration. For example, time stretching 10 seconds of audio takes less than 10 seconds. This basically means that you can play the result immediately and without interruption, as it is being transformed.

Another definition of real-time is to transform audio and play the result on the fly as it comes from the microphone or audio input. This is not possible with Tachyon, and does not make a lot of sense for time stretching anyway.

Another (wrong) definition of real-time is "really fast" or "very high speed". If that is your definition of real-time, let's just say that Tachyon is designed to be real-quality rather than real-time.

Is Tachyon available as a plugin (VST, AU, etc)?

No, the current version is only available as a stand-alone application. A future version might be available as a plugin.

Some DAW might support drag and dropping audio files or tracks to the "Input Files" list of Tachyon, and then drag and dropping back the transformed files or tracks from the "Output Files" list. While not as practical as a plugin, this feature might simplify the workflow when working with both a DAW and Tachyon.

Can Tachyon use multiple CPU cores?

Yes and no.

  • Tachyon uses only a single core (at a time) when processing a single audio file.
  • However, when transforming multiple files, Tachyon can use multiple CPU cores simultaneously to process different files simultaneously.

For example, if there are 4 CPU cores, and you transform 10 files, Tachyon will start transforming the 4 first files at the same time using the 4 available CPU cores, and the 6 other files are held in a waiting queue. As soon as one of the files is finished, the corresponding CPU core immediately starts processing the next file in the queue, keeping all the CPU cores busy.

Note that by default, Tachyon uses at most half the number of logical CPU cores available, which might not always correspond to the number of physical CPU cores available. This setting can be changed in the global settings (see section 4.3.2)

Does Tachyon have feature XY?

Whatever XY is, the answer is probably no.

Tachyon does one thing, and does it well. That one thing is time stretching audio files.

How can I do pitch shifting?

Tachyon does not implement pitch shifting. However if your DAW provides resampling, it is possible to do pitch shifting by combining resampling with time stretching. For best results, you should always resample first, and then time-stretch; regardless of whether you want to pitch shift up or down. Please note that pitch shifting that way will not preserve the formants.

What are the main limitations of Tachyon?
  • Tachyon only does time stretching. It does not do pitch shifting.
  • Tachyon does not support sliding time stretching (time stretching by an amount that is varying with time).
  • Tachyon is a standalone application. It is not available as a plugin.
  • Tachyon can only write audio files in the WAVE (*.wav), AIFF (*.aiff, *.aifc) and AU Sun/NeXT (*.au) formats, with PCM encoding (including 32-bit float). It can read these formats and a few compressed formats: MP3, FLAC, OGG, OPUS and M4A.
  • The Mini Player included in Tachyon might not be able to play some multi-channel or high-resolution audio files. But they can be transformed without problem.
  • Tachyon is not designed to transform files in real-time.
  • Tachyon is designed for the best possible quality. As a result, it needs a lot of processing power and a lot of RAM.

5.2 System Requirements

What are the system requirements?

  • Operating system:
    • Windows 64-bit: Windows 11 or later, Windows 10, Windows 8, Windows 7 (SP 1).
    • Mac OS: Mac OS X 10.11 "El Capitan" or later (64-bit Intel), or macOS 11 "Big Sur" or later (Apple M1).
      • Note: Other versions are available, but they have been less extensively tested: Windows 32-bit, Linux (depends on JRE version 11 or greater), Generic (requires a JRE version 8 or greater). Use these at your own risk, and be sure to try the demo version first.
  • Memory:
    • Minimum: ~600 MB available for Tachyon, meaning a 1 GB system. This allows transforming one stereo, 384 kHz audio file at a time, or one 5.1, 96 kHz audio file at a time, both at the maximum quality.
    • Recommended: at least 4 GB.
  • CPU speed: Any, but at least 2 GHz is recommended. The faster the CPU, the less time it takes to transform a file.
  • CPU cores: The more cores available, the more files Tachyon can process at the same time. Note however that multiple cores will not make the transformation of a single file faster. Tachyon can only use multiple cores at the same time to transform multiple files at the same time.
  • Disk: Disk speed is generally not important. Disk capacity must be sufficient to store the original, transformed and temporary (being processed) files.

Note that Tachyon requires quite a lot of memory. See the next question.

How much memory does Tachyon take?

This depends on several factors: the sampling rate of the audio files being processed, the number of channels, the quality setting, and the number of files being transformed at the same time. Note that the length of the audio files and the resolution (or bit depth, such as 16-bit, 24-bit or 32-bit) have no effect on the amount of RAM that is used. The following table shows the approximate memory usage for a few examples:

  Quality 2 Quality 3 Quality 4 Quality 4 -
4 files simultaneously*
Sample Rate Mono Stereo 5.1 Mono Stereo 5.1 Mono Stereo 5.1 Mono Stereo 5.1
44.1 kHz 28.1 MB 33.5 MB 55.0 MB 57.5 MB 88.9 MB 214 MB 83.3 MB 136 MB 349 MB 243 MB 455 MB 1.27 GB
48 kHz 28.4 MB 34.0 MB 56.5 MB 59.9 MB 93.4 MB 227 MB 85.8 MB 141 MB 362 MB 252 MB 473 MB 1.33 GB
96 kHz 32.3 MB 41.0 MB 75.7 MB 89.6 MB 149 MB 388 MB 116 MB 199 MB 528 MB 364 MB 693 MB 1.96 GB
192 kHz 40.0 MB 54.8 MB 114 MB 149 MB 261 MB 709 MB 178 MB 314 MB 860 MB 587 MB 1.11 GB 3.24 GB
384 kHz 55.3 MB 82.5 MB 191 MB 268 MB 484 MB 1.32 GB 300 MB 545 MB 1.49 GB 1.01 GB 1.97 GB 5.79 GB
*Requires at least 4 CPU Cores

Green cells correspond to possible combinations with 1 GB of RAM (or more) available for Tachyon (1.5 - 2 GB system, or the Windows 32-bit version of the application).
Orange cells correspond to possible combinations with 3 GB of RAM (or more) available for Tachyon (4 GB system).
Reds cells correspond to possible combinations that require a system with more than 4 GB (more than 3 GB available for Tachyon).

The maximum amount of RAM Tachyon will use is:

  • About 1 GB on 32-bit Windows (regardless of the memory actually available, meaning that the application might swap if less memory is available)
  • 75% of the physical memory on 64-bit systems. For instance, on a computer with 8 GB or RAM, Tachyon will use up to 6 GB. Note that this is based on the total amount of physical memory installed on the computer, and not on the amount of actually available free memory.

If the maximum memory is not sufficient to transform a file (for instance if it has many channels and/or a high sample rate), Tachyon will not transform it and display an error message. If the maximum memory does not allow transforming multiple files at the same time, Tachyon will automatically reduce the number of files that are transformed simultaneously, meaning that the number of CPU cores that are used will be reduced too.

Does Tachyon require an internet connection?

Tachyon only requires an internet connection when you ask it to:

  • Check for updates
  • Display the online documentation

Apart from that, no internet connection is required while using Tachyon. In particular, no internet connection is required to validate a license key.

What kind of copy protection is used?

Only a license key (also known as a "serial key").

There are not separate demo version and full version. There is only one version that runs in demo mode as long as no license key is entered. As soon as a valid license key is entered, all features are enabled and the application runs in "full" mode.

No internet connection is necessary when entering a license key to register the application and unlock all features.

5.3 Buying & License

Where can I buy Tachyon?

Tachyon is available for buying on its home page here.

Be sure to try the demo version (available at the same place) before buying.

Note: the selling process is handled by the KVR Marketplace. Here is the KVR Product page for Tachyon Audio Time Stretch.

How to install Tachyon?

When you buy Tachyon, you should receive an email with a Licence key. If not, contact your reseller.

To install Tachyon:

  1. If you have not installed it already, download and install the demo version from tachyon-sonics.com. Else proceed with the second step.
    • The email with the license key may have a direct download link. You can use it a well.
    • There is no separate "full version". What matters is the license key: enter it in the demo version and it will unlock all features.
  2. Once installed, start Tachyon Audio Time Stretch. It will open a dialog to enter the license key. Copy the license key you received by email and paste it in the dialog (there is a button above the license key field). Then click on the button to register it and unlock all features.
    • You can also click on the button to register later. In that case the application will start in demo mode (with limited features) until registered. You can also use the Help, Enter License Key... menu to enter the license key after the application has started.

Important:

  • No refund will be issued. Be sure to try the demo version first.
  • Keep your license key! If you buy a new computer, the license key will allow you to unlock Tachyon on the new computer.

Notes (Windows):

  • When downloading the installer, if a warning message "Tachyon Audio Time Stretch.msi is not commonly downloaded..." appears, click on and choose Keep. Then choose "Show More" and "Keep Anyway" if asked.
  • When running the installer, if a SmartScreen message "Windows Protected Your PC" appears, click on "More Info" and then .
  • If you are uncomfortable with the above:
    • These warnings occur because the file is not commonly downloaded (which is expected for a niche market such as audio time stretching), and not necessarily because the file contains a virus or a threat.
    • Make sure you downloaded the installer from www.tachyon-sonics.com or from www.kvraudio.com. These are the only two official sources for Tachyon Audio Time Stretch. Downloads of Tachyon Audio Time Stretch from other sources might not be legit.
    • Scan the installer with your antivirus software first. It should report no threat.
    • Verify that the installer has a proper digital signature (Name of signer: Nicolas Juillerat). Use the "Properties" context menu on the downloaded installer file in the file explorer.

Is there a demo version?

Yes, you can download it from here.

Note that there is only a single version that acts both as a demo version and as a full version: it runs in demo mode as long as no license key is entered, and in full mode as soon as a valid license key is entered. When you buy Tachyon, what you actually buy is a license key to unlock all features.

For that reason, the application will ask you to enter a license key every time you start it. Just click on the button to use it in demo mode, and then on .

What are the limitations of the demo version?

  • The demo version will not transform more than 30 seconds of audio. If you transform an audio file that is longer than 30 seconds, only the first 30 seconds will be transformed.
  • The demo version should not be used for commercial activities.
  • The demo version will ask you to enter a license key every time you start it, so you need to click on every time.

Should I buy the full version if I never transform more than 30 seconds?

Yes.

The 30 seconds limitation allows you to try before you buy. However, this does not mean that the application is free for less than 30 seconds audio files. If you plan to continue using it after a 30 days evaluation period, you must buy it.

Can I use my license key to install Tachyon on my other computers?

Yes as long as Tachyon is not used on more than one computer at a time. Else, you need additional license keys.

I bought a new computer. How do I transfer the License?

Just download the demo version on your new computer, install it, start it, and enter your license key. This will unlock all features.

If you still have the email with the license key, you can copy it from there. In the Tachyon application, you can then use the button when your license key is asked.

If you still have your old computer, you can start Tachyon, choose the Help, View License Key... menu, and click on the button. You can then paste the license key on a text file and transfer that file to your new computer.

I bought the Windows version and switched to Mac (or Linux). Do I need to buy the Mac (or Linux) version?

No, you can just download the demo version for Mac (or Linux), and then enter the license key of the Windows version you initially bought to unlock all features. This also works the other way around. The license key is not bound to the operating system. This also works between the 32-bit and 64-bit Windows versions.

You can use the Help, View License Ley... menu to view the license key on your old computer. Right-click on it and choose the Copy context menu to copy it to the clipboard. From here you can paste it in a text file and transfer it to your new computer. On the new computer just paste the license key on the dialog that asks for it when you start the demo version. You can also use the Help, Enter License Key... menu after the application has started.

Can I buy a license for one of the unsupported versions (Linux, Windows 32-bit, etc.)?

Yes. What you need to do is to buy one of the supported versions (Windows 64-bit or Mac OS). You will receive a download link for the installer and a license key. Just ignore the download link. Download the demo version of the unsupported version you want, start it, and enter the license key to unlock all features.

Remember this is unsupported. Try the demo version first and be sure it fits your needs!

How is Tachyon licensed?

Tachyon is proprietary software. It comes with the following End User License Agreement.

How do I uninstall Tachyon?

Use the standard built-in feature of Windows:

  • On Windows 10 or later, from the Windows Start menu, choose "Settings" (a gear wheel icon), then click on "Apps" and/or "Apps & features".
    • On Windows 7 or 8, from the Windows Start menu, choose "Control Panel", then click on "Program and Features".
  • Search for "Tachyon Audio Time Stretch" in the list.
  • Click on it, and then on Uninstall (depending on the Windows version, this is either a button on the top of the list/entry, or a choice in the "" menu).

Warning: if you uninstall and reinstall Tachyon, you will need to enter a license key again.

5.4 Usage

Why are the transformed files less loud than the original files?

While the process of time stretching preserves the loudness, it frequently increases the level of individual peaks, which would result in clipping. This is especially true with modern mastering that have been brick-wall limited with virtually no headroom. By default, the Tachyon application automatically reduces the loudness of the transformed files as necessary to prevent clipping (peak normalization).

This behavior can be modified by disabling the "Prevent Clipping" option in the transformation settings. See section 3.2.3 to change the setting on individual files, or section 4.3.1 to change the setting globally. Disabling this option might result in clipping on the transformed file, unless the output file format is set to one of the 32-bit float formats. Note that with these formats, samples might still be above the ±1 maximum "normalized" value and do clip when played, but the true values are not lost and a DAW can then normalize them properly or apply a suitable dynamic range compression.

In general, we recommend you transform audio files with sufficient headroom to prevent clipping or automatic lowering of the volume. Audio files normalized to EBU R128 for instance rarely clip when transformed. Dynamic range compression, brick-wall limiting and any other form of loudness maximization is better done after time stretching, if ever.

I cannot play the transformed file with my favorite audio player!

Tachyon saves the transformed files in PCM 32-bit floating-point format by default. This format is recognized by most professional DAW, but might not be recognized by consumer audio players.

You may want to save the transformed files in PCM 16-bit or 24-bit instead. See section 3.2.3 to change the output format in which transformed files are saved.

Can I know how much time is remaining until a transformation is finished?

If a file is currently being transformed, select it in the "Output Files" list, and click on the button. In the "Transformation" tab, there is an item labeled "Processing time" that displays both the time elapsed so far on this file, and an estimation of the time remaining (ETR). The estimation might be inaccurate or unknown at the beginning of the processing, but it gets more accurate as the processing advances.

If multiple files are processed, there is no estimation of the total time remaining.

Why does Tachyon only transform the first 30 seconds?

Because you are using the demo version. The full version does not have this limitation, but is not free. You need to buy a license key and to enter it in the Tachyon application.

Click here to buy the full version.

Where are the transformed audio files stored?

By default, each transformed audio file is stored in the same directory as the original, untransformed file. They are stored here only when the transformation has completed. During the transformation, the partially transformed files are stored in the default temporary directory of the system (in a raw format), and are then moved to the final location and converted to the target format (.wav, .aiff or .au) once the transformation is finished.

It is possible to instead explicitly specify an output directory in which the fully transformed files are stored. See section 3.2.3 (individual file setting) and 4.3.1 (global setting). See section 4.3.2 (global setting only) to change where the partially transformed files are stored.

Notes:

  • Right-clicking on a transformed file (in the "Output Files" list) and choosing the Show in Windows Explorer menu will open the containing folder in the Windows Explorer and select the file.
  • Moving the mouse over a transformed file (in the "Output Files" list) and waiting one second will show the full file path on a tooltip

Is it possible to transform by more than 4 times slower or faster?

No, at least not directly. Furthermore, this is not recommended as Tachyon is optimized (in terms of processing quality) for the 0.5 (two times faster) - 2.0 (two times slower) range.

If you still absolutely want to transform to more than 4 times slower or faster, you might do it in multiple steps as follows:

  • First compute the time stretching ratio as a "mathematical length ratio" by dividing the desired output length by the input length. For example, 10.0 for ten time slower, or 0.1 for ten times faster.
  • Calculate the square root of that number. For instance, 3.162 for 10.0 (10 times slower) or 0.3162 for 0.1 (10 times faster)
  • Transform the file a first time using this calculated ratio (Choose "Ratio" in the drop-down below "Time Stretching Factor" before entering the value).
  • Once the transformation is finished, drag and drop the resulting file from the "Output Files" list back to the "Input Files" list and transform it a second time, with the same calculated ratio.
  • The resulting file of the second transformation is the desired result!
  • If the square root computed in the second step is still outside of the 0.25 - 4.0 range, take the cube root instead, and transform the file three times.
  • When slowing down, you may want to increase the crisp/smooth value. When speeding up, you may want to decrease it.
Mind that the quality of the result will be significantly lower than with files transformed a single time and within the recommended 0.5 (two times faster) - 2.0 (two times slower) range. The quality might also be significantly lower than by using an algorithm dedicated to extreme time stretching. A future version of Tachyon might provide an algorithm dedicated to extreme time stretching.

How can I adjust audio speed after a video frame rate conversion (PAL <-> NTSC)?

On the drop-down under "Time stretching factor", choose Video FPS from/to (FPS = [video] Frames Per Second). Enter the original video frame rate in the "From:" field and the final video frame rate in the "To:" field.

For example, a typical NTSC to PAL conversion plays a video track originally at 23.976* FPS (NTSC) on a 25 FPS system (PAL). In that case, to stretch the audio accordingly, enter 23.976 in the "From:" field, and 25 in the "To:" field.

*This value originates from a 29.97 FPS (the true NTSC FPS) video track converted by an approximate 24/30 ratio. An exact conversion of a 29.97 to a 25 FPS video track is generally difficult to perform with good image quality, which is why the resulting video track is typically at 23.976 FPS instead of 25. However, in case the video track is converted exactly (with an exact 29.97/25 ratio), there is no need to stretch the audio track.

When in doubt, you can also choose Length from/to in the drop-down under "Time stretching Factor", and enter the exact initial and final length of the video to properly stretch the audio accordingly.

Note: Tachyon does not handle video or movie files. You must extract the audio tracks from video files with your video editor in order to stretch them using Tachyon.

Is it possible to preview the result before transforming a file?

Yes and no. There is no "preview" feature.

However, when you hit the button to transform a file, you do not need to wait until the file is fully transformed to play the result.

Just select the file (in the "Output Files" list) and hit the button (under the "Output Files" list) and Tachyon will play as much audio as is already transformed. Note that you might still need to wait some seconds (and even longer for files with a high sample rate) before the first few seconds of the file are transformed and can be played. As more of the file is transformed, the player will allow you to play more.

The player itself shows both the playback position and the amount of audio produced yet (the "processing" position); see section 4.1. The current duration of the transformed audio is also displayed next to the file name in the "Output Files" list, and is regularly updated until the transformation is finished.

If the file is not fully transformed but you are not satisfied with the result, right-click on the file in the "Output Files" list, and choose Abort Processing from the contextual menu to cancel the transformation.

If you want a quick and low-quality preview of the whole transformed file, see section 3.2.2 to lower the processing quality (which results in faster processing).

It seems that the processing occasionally slows down or even stalls

Choose the File, Settings... menu, select the Processing Tab; under Prevent system sleeping, be sure the ☑ While tranforming files option is checked. Else, the system might go to sleep before all files have been transformed by Tachyon, which will pause the processing until the computer is awakened again. If this option is not visible, you may need to update the application.

Also note that by default, Tachyon transforms files using low priority (or background) threads, to make sure the system does not get unresponsive. The consequence is that other CPU-intensive processes that do not run with background priority might sometimes "steal" CPU cycles from Tachyon. You can also change the priority of the processing threads used by Tachyon in the global settings described in section 4.3.2.

Note: because of a bug, sometimes the GUI does not respond when returning from sleep mode or lock screen. Just move the Tachyon's main window and the problem should go away.

Why does Tachyon give me an error when playing a file?

Generally, because the sample rate or the number of channels is not supported by the Mini Player integrated in Tachyon.

This can also happen if another application has exclusive access to the default sound card.

The Mini Player in Tachyon is a basic player: it plays through the operating system's default audio output, and does not try to detect or use advanced ASIO sound cards automatically. If the default audio output does not support the sample rate or number of channels, the player will give an error. Note that Tachyon will still be able to time-stretch the files even if it cannot play them.

In Tachyon, right-click on a file, and choose the Show in Windows Explorer menu to show the file in the Windows Explorer. You can then play it with your favorite player or DAW.

How can I make Tachyon faster?

  • Check that your are running on AC power and not on battery.
  • Transform files using quality 3 instead of the default 4: 95% of the time the result at quality 3 is indistinguishable from quality 4, as long as you do not change the Crisp / Smooth advanced setting.
    • See section 3.2.2 to change the quality setting on individual files.
    • See section 4.3.1 to change the default quality setting for all new files.
  • Consider using Quantum Audio Time Stretch.
    • Quantum is an application similar to Tachyon, but optimized for the best speed/quality trade-off. Quantum uses the 10% of Tachyon that are responsible for 90% of the quality. As such, Quantum is much faster than Tachyon while providing a quality that is very close.
    • Quantum is free for Tachyon users: download the demo version, start the application, and then enter the Tachyon's license key to register the full version (choose "Tachyon" for the serial key type). If you have no license key for Tachyon, it is also possible (and cheaper) to buy a license key for Quantum only.

Tachyon does not look professional

Choose the File, Settings menu; select the "Appearance" tab; Select Flat Dark in the "Appearance" drop-down, and click on . Now Tachyon looks professional.

How can I get support?

Tachyon was not developed by a big company, but by a single person (Nicolas Juillerat, from Fribourg, Switzerland) working on it about one day a week. As such support is not expected to be the same as that of big companies.

You may get answers by:

  • Reading this user manual. Click here to go to the table of content.
  • Try the demo version before buying the full version to make sure it suits your needs.
  • Ask your question in the KVR Forums.
  • Ask your question by email to tats(at)tachyon-sonics(dot)com. Mention "Tachyon" in the subject. Answer may take 1 to 7 days.

5.5 For further information

Visit the Home Page of Tachyon Audio Time Stretch.

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