Due to changes on the Tensor circuit board, there are different firmware packages based on serial number.  The firmware update will fail if you use the wrong file for your pedal (it will not damage your pedal).


Serial number 108-067000 and higher:

Use the tensor_mm.nn.pp.xxx.zip firmare update file (example: tensor_1.1.2.89.zip). These pedals were built starting in late 2018 and have a square opening in the enclosure around the USB port. The VERSION.TXT file (see below) will say “Bootloader 1.1” or a later version.


These Tensors support stereo input and output, or mono with longer loop time.


Serial number 108-066999 and lower:

If your Tensor has been upgraded, use the tensor_mm.nn.pp.xxx.zip firmare update file (example: tensor_1.1.2.89.zip).

Otherwise, use the tensor_rev_abc_mm.nn.pp.dmg (Mac) or tensor_rev_abc_mm.nn.pp.zip (Windows) firmware update file (example: tensor_rev_abc_1.1.2.zip). These pedals were built in 2018 and have a slightly rounded opening in the enclosure around the USB receptacle. The VERSION.TXT file (see below) will say “Bootloader 1.0”.


These Tensors support mono input and output (but can be upgraded to stereo).


How to find the serial number

The serial number sticker has a bar code and a number that starts with "108-" (108 is the Tensor's part number).  We put three serial number stickers on each pedal:

  • on the box sticker
  • on the bottom of the pedal
  • on the inside of the bottom plate


How to tell visually

Here is a side-by-side look at three Tensors.  The left  and center Tensors are older (< 108-067000) and have a slightly rounded opening around the USB receptacle.  The right Tensor is newer (> 108-067000) and has a squared off opening around the USB receptacle.


Here is a closeup of the middle and right Tensors:


You can sometimes tell by looking at the LEDs.  Early Tensors had LEDs with rounded tops that poked up through holes in the enclosure.  Later Tensors use frosted light pipes that are less rounded and completely cover the hole.  This changed happened earlier than the enclosure hole.  Here are the same three Tensors:


Here is a close of of the LED and light pipe:


To tell which version of firmware your pedal is currently running:

1. Hold down the left footswitch and connect power.

2. The blue LED will blink.

3. Continue holding the left footswitch for 2 seconds.

4. The blue LED will turn solid. The pedal is now in USB Mass Storage mode.

5. Connect the pedal to the computer using a mini USB cable.

6. Open the TENSOR drive on your computer.

7. Open the VERSION.TXT file in a text editor.