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Twin MkIIIS Support Page

Shift Line Twin MkIIIS is a tube guitar preamplifier with a built-in cabinet simulator based on the Impulse Response Convolution technology.

This page contains extra info on the device's operation:

Standard mode

The device can utilize both stock and third-party impulses in WAV format. All the needed folders are automatically generated on the microSD card upon initial use (those folders are SD:\SL_IR\A\ and SD:\SL_IR\B\). In order to replace an impulse, simply delete the old one from one of the folders and place the new file into the same folder. For instance, to replace impulse A, go to SD:\SL_IR\A\ and replace SL_19A19.WAV with an impulse file of your choice (required format: 24bit 48kHZ WAVE PCM1, uncompressed). Next, insert the microSD card into the Twin MkIIIS and set the CAB switch to A in order to hear the new impulse. When no microSD card is inserted, the Twin MkIIIS uses built-in impulses. This way, you can extend your impulse pool to four or pair a stock impulse with a third-party one on the microSD card.

In this mode, the Twin MkIIIS will apply the built-in neutral power amp simulation to any impulses you upload.

Advanced mode

To simulate a different power amp, use the patch generator or create your own patch in SigmaStudio. Then, create an SL_HEX folder in the root directory of your microSD card. In the SL_HEX folder, create folders A and B (corresponding with the CAB switch positions on the device). Place the HEX file into any of the two folders (for example, SD:\SL_HEX\A\drive.hex). Each of the two folders can contain one HEX file. Make sure to observe folder hierarchy. Note that each HEX file's name should only consist of numbers and Latin letters.

If the microSD card has an SL_HEX folder in its root, the device will ignore the SL_IR folder and use alternative patches instead of impulses. The original firmware and impulses are still available for use: just eject the microSD card from the device.

You can download an archive with correct folder hierarchy below and extract it to a blank microSD card. The archive contains two power amp simulations with an impulse of a Fender Twin cabinet with two JBL D120F speakers. After that, you can simply replace the patch files with your own.
You can also download the archive containing all power amp simulations created for the Twin MkIIIS so far.
WARNING: HEX files created for the CabZone LE/CabZone X will NOT function properly with the Twin MkIIIS/Olympic MkIIIS because of level mismatch. We strongly advise against using CabZone LE/X patches in our preamps.

The same patches can be used both in the Twin MkIIIS and in the Olympic MkIIIS. Either device can utilize guitar and bass cabinet impulses.

Online patch generator for Twin MkIIIS

The Twin MkIIIS has only one power amp simulator (neutral) in stock. In most cases, it is enough — but you can also simulate other power amps if you wish. To do that, you need to create a user program (patch) containing the cabinet impulse and the power amp impulse of your choice (this can be done with our online HEX file generator). Once the patches have been uploaded to the device, the CAB switch will select between "power amp + cabinet" combos, which means you can create a pair of presets tailored to your needs.

This tool allows you to create a HEX file, which is an alternative control program / patch for use with the Twin MkIIIS's digital cabinet simulator.

To create and download a HEX file containing a "power amp + cabinet" combination, follow 3 simple steps:
  1. Select an impulse from the list:
    or upload your own (wav pcm, mono, 24 bit, 48 kHz, uncompressed):
  2. Select power amp:
    Select power amp set:

Additional info

  • The digital cabinet simulator used in the Twin MkIIIS is based on DSP ADAU1701 (input: ADC0, output: DAC0).
  • The built-in DSP chip sees the microcontroller as a ROM chip in selfboot mode.
  • SigmaStudio is the official programming environment for the DSP chip. SigmaStudio allows to download ROM files in HEX format for use in selfboot mode. This can be used to create custom patches. Create a program, compile it, give the resulting HEX file a name in Latin letters and place it into either folder on your microSD card (for instance, SD:/SL_HEX/A/twin_patch.hex).
  • The FIR block in SigmaStudio accepts mathematical impulse factors. To turn a WAV impulse into a list of factors, you can use the WAV2FIR online tool.

User guide

Impulse packs

We have released several impulse packs for guitar and bass, and we are going to keep adding more packs in the future. You can either use those impulses in our devices directly or generate complex patches with them.