This is an attempt to cover the sequencer bugs in the Behringer TD-3. As someone who has spent a lot of time analysing and replicating every single detail of the original 303 sequencer (along with Anton Savov for the n0nx0x project), I feel I'm somewhat an authority on the matter. It came as a big surprise to me that they decided to clone the original sequencer. And they didn't do a terrible job at it too, although it's obvious they chose a completely different implementation under the hood which sadly leads to some bugs and annoyances.

Hopefully listing all actual bugs here will provide more insight to the community and perhaps the manufacturer.

Note: This list is a work-in-progress and I plan to keep it up to date when new bugs appear or when bugs get fixed. Feel free to contact me if you find inaccuracies or unlisted bugs.

Changelog

10/3/2020: Initial version based on firmware version 1.2.5 (21/2/2020).

12/3/2020: Some minor changes and publication

15/3/2020: Added release notes for 1.2.6. Indicate that midi slide bug is fixed there.

Behringer TD-3 bugs

Pattern Play

Transpose: In midi slave mode, transposing a pattern when the sequencer is not playing will not apply the transpose to the pattern when playback starts.

Transpose: In midi slave mode, stopping a transposed pattern and restarting will keep the transpose for 1 loop and then play it normal. When pressing transpose it will show the pattern as non-transposed.

Impossible to press both Pattern Section (A/B) and a pattern slot at the same time, which makes switching patterns between sections very hard and error-prone.

Pattern Edit

Note attributes (e.g. UP) are not always stored. They appear stored and then when switching to another pattern and back they are gone. Still need to find the exact steps to reproduce this, from the 30 somewhat patterns I entered manually from pattern sheets, it happened twice, after using the copy feature.

You can only enter 16 notes in Pitch Mode. Not a "bug" per se, rather a wrong implementation choice which also causes you not to be able to write multiple patterns in one go (which also block tap entry across patterns).

Tap write: on the 303 you can hold any of the pattern slot (1..8) keys to sustain tapped notes. This really helps with inputting patterns with tied notes. This is completely not implemented on the TD-3.

Tap write does not work in midi slave mode.

Track Play

Transpose: In midi slave mode, if the first pattern in the track is transposed, it will not play transposed the first time.

Transpose: in some situations the transpose is not saved. I'm still trying to understand when/how this happens. Sometimes it is saved and then next time I check the track is wrong again.

On a 303 you can hold Transpose during track play to follow the pitch changes. Here it does nothing.

When holding the Bar button to see which bar you are on, the speed of the blinking is wrong (should be faster).

Track Edit

No issues noticed yet. Will test more in depth.

Midi bugs

As expected (everyone gets this wrong!), a combination of slide, accent and identical notes does not work the way it should. Too bad, as those are usually the source of many interesting patterns. I tested based on the 303 and midi article by Anton Savov which investigates the problem and possible solutions (@Uli: give this link to your engineers). The result is obviously broken. As described in the article:

"The pattern becomes fragmented, and/or some notes get cut-off short, and/or some slides are gone."

That is exactly what happens here (first is n0nx0x2, second is TD-3):

Update: this issue is fixed in 1.2.6:

Release notes

This are the copied release notes in case the Behringer links change/go dead:

Version 1.2.6 (12 Mar 2020) link

Fixed: MIDI slide doesn’t work when the overlapping note is same with the previous one.