G2 NoteSeq is unstable when rec inputs are connected

arno

Hi there,

This is my first posting on this forum so please be gentle Smile

I’ve found some weird behavior in the NoteSeq module. I think it is a bug. Can others confirm this ?

Here are my findings

Nord Modular G2X
Os 1.40

The NoteSeq module is the only sequencer module with a option for on the fly recording. By setting a high signal on the Rec Enable input the module will go into recording mode. When Rec Enable is set back to low recording will stop and playback will begin. In playback mode the NoteSeq module should act like a NotSeq module that does not have anything connected to the Rec Enable input. It is my experience that it does not.

NoteSeq has two outputs. A Value output and a Trigger Output. I cannot find it in the documentation, but I should say that both outputs should be set at the same time. Or, if this is not possible, that the value output should be set before the trigger output goes from low to high. Only this way you can be sure that once a trigger output is fired the corresponding value output is ready to be processed.

I have found however that when any input is connected to Rec Enable, or Rec Input, the value output is set AFTER the trigger event goes from low to high. And in some cases even set to a wrong value.

See patch NoteSeqBug1
This is the thing that got me started. Here we see two NoteSeq modules in sequence. I’ve made them 4 steps for the sake of this demonstration. It sends the same note over and over again to SlotB. If you keep this running long enough you will hear that in some cases step 1 of the first NoteSeq gives a E2 note instead of a G2 note. This problem will not occur if I disconnect both Rec Input and Rec Enable cables.

Now see patch NoteSeqBug2a, NoteSeqBug2b and NoteSeqBug2c
Once an event is triggered a Sample&Hold module is used to store the Value output. Output is then send to SlotB.
This is what i get :
NoteSeqBug2a : Note C#3 is played, but on step 2 of the first NoteSeq not on step 1 as expected
NoteSeqBug2b : Note C#3 is still played on step 2. On step 1 E3 is being played. On step 1 of NoteSeq 2 a very low note is being played
NoteSeqBug2c : Note C#3 is played on step 1 of the first NoteSeq as expected.

Note the differences between these 3 patches. It is the wiring on the Rec Enable and Rec Input.

Now see patch NoteSeqBug3
This time i’ve added a delay, as to give NoteSeq a little time to set the value output, after it has put the trigger output from low to high. At 0.09msec it behaves as NoteSeqBug2c. At 0.05 it behaves as NoteSeqBug2b. At 0.01msec it behaves as NoteSeqBug2a. Note how al this weird behaviour stops when you disconnect the Rec Input and Rec Enable cables.

In short. The workaround to the problem of wrong notes in NoteSeqBug1 is to add a delay of 0.09 msec. I have found however that as more sequence modules are added to the patch this delay value should be set higher.

Other workaround of course is do disconnect the recording cables once they are not used any more

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SeqNoteBug2a.pch2

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