MIDI clock bug

Bug description (state clearly and simply): SSP step sequencer don’t reacts to MIDI start & stop commands

Steps to reproduce (use numbered list): connect a MIDI sequencer to SSP midle USB port, start your sequencer, SSP step sequencer should start too

Software version (blank if unknown): 12082018

Type (major or minor): major

step sequencer syncs alright with MIDI clock, it just don’t start nor stops
you have to engage the int clk button to start, even when MIDI clocked
to stop, you have to disengage the int clk button

the clock is quite slow on the pickup too (i use an akai MPC4000, which is known for super stable clock)
-a 140.5 BPM needs -at least- 4 (4/4) measures to lock onto the clock

there is some jitter too ; when not running (but still sending MIDI clock signals, so is the nature of the MPC) there is a jitter on a 140.5 BPM clock from 140.350 to 140.890 (in its extremes)

when running -as mentioned before it needs some measures to fully lock- it jumps from 130 BPM to 189 BPM again, in the first measures
thereafter there is the normal jitter you could expect in this kind of device

of course some jitter is inevitable and maybe even wanted to induce a more human feel
but i must say that jumping to extremes when clocking may not be musical

all in all, i must further test to hear what it sounds like (esp with the step sequencer triggering sounds) to hear if it sounds out of focus/time or not
but this has been mentioned before (and answered ; that the dev. focus is not on resolving timing issues but on clearing overal/kickstarter goals)

after some tests it is clear that the step sequencer is not running in sync : a 32 step sequence with 1 gate (and a clock division of 8) slides from beat 3 / bar 1 all the way round on a 8-10min period, off course this behaviour can be tied (maybe) to the fact that i had to engage both the MIDI clock & the int Clk button to sync AND start the step sequencer

It might not react to midi stop at the moment but it SHOULD react to midi start and midi clock. Did you enable the midi sync button?

The int clk button is to make the sequencer run with internal clock. You have to turn that off if you want to drive it with MIDI clock signals.

I think the clock messages are handled by the same code as the tapping which might be the reason for this. Maybe I can improve upon this by handling these two differently in the code since it’s assumed that the MIDI clock is accurate while tapping is not.

@IvanS had a latency issue with triggering the sampler with an external sequencer but I haven’t heard from him whether his problem is solved or not. I reduced the audio buffer size to deal with this following his request.

please check whether you disabled the int clk of the sequencer and enabled the midi sync button and then try again :slight_smile:

yes (and tried every other possible combination of the other two choices int/sys clk)

i am syncing MIDI devices since 1985, so i know what i am doing (only in music, and then again…)

but i agree, it should react to MIDI start, stop - and even continue - but it does not at the moment

please do, i have a feeling that MIDI clock signals have to have priority over (someone tappin’) a button
if you assume that MIDI clock is accurate, how come there is this latency/jitter/slow reaction?

i will follow up with testing on the trigger latency, but this is another issue

confirmed, @bert will work on a solution
maybe also de-couple the tap button from the clock signal to get a more stable sync/tempo
see here for more : Sequencer Redesign

when the midi clock moves to the midi module you will feed the clock signal into the clock input of the step sequencer so it will automatically override/bypass the tap code.

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just saying that since the last update (210918) the stepsequencer doesn’t react to incoming clock messages anymore
before, you could see the clock jumping all around, and -in the end- following MIDI tempo
but this is not the case anymore

you mean incoming midi clock messages or a clock signal feeding into the clock input?

what are the clock related settings in the step sequencer set to?

i didn’t touch any midi clock/sequencer related code on the last 2 updates… :thinking:

i am talking about the MIDI clock
the clock settings i tried are int Clk on/off and alternately MIDI S on/off
before, when MIDI S on, i could see the Tem field following the (external) MIDI clock tempo

just tried this here with the latest software and it works just fine

well i don’t get anything, but i a sending MIDI timing, and start/stop signals
it used to work (only tempo readings) in previous software builds
and now it doesn’t anymore
wil try with direct connection MPC->SSP

is that USB midi interface ‘directly’ connected to the step sequencer (tempo) input?
or did you patched a MIDI module in between?
did you engaged MPE or not?

this is directly connected to the step sequencers at the moment, but like I said I will move the MIDI clock stuff into the MIDI module and when that is done you’ll be feeding a clock signal from the MIDI module into the clock input of the step sequencer and the hardwired connection between MIDI input and the sequencers will be gone. MPE or not has no effect on MIDI clock stuff.

STEP sequencer still doesn’t lock onto MIDI clock (or MTC)

now it doesn’t even start when you send it a MIDI start event

how long will this take to fix ??

did you turn off internal sync on the step sequencer and turn on midi sync? it should sync to midi clock.

keep in mind i just finished rewriting the multichannel recorder so it works on large files without loading them into RAM which is something you requested and which took a good 2 months of work.

I cannot do everything at the same time and we have a business to run which involves a lot more than just writing code. we just finished the synthplex show.

there are also many other users who request features or fixes and we do our best to handle requests fairly.

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it just doesn’t work @bert. it should, but it doesn’t
(yes, i configured as requested)

when i was @ your place 6m ago you said it was a fairly easy fix

i’m not blaming anybody
but a target date would do miracles

yes, and then there were numerous other requests for other features and fixes so this was pushed onto the backlog.

i’ll test the midi sync with my keystep somewhere later this week.

i can’t commit to any dates… updates are posted on a regular basis as time allows.

okay thank you bert

I plugged my arturia keystep into the SSP, put a sequencer module in the grid, made sure Int Clk was on and MIDI sync too, and then I tapped the tempo on my keystep using its tap button while I listened to a metronome in ableton live, and I get the same tempo in the step sequencer on the SSP as I have in ableton live.

what exactly is not working in your case when using your MPC? I know that the syncing is not fast and takes a few seconds to be correct, I still have to improve that.

you saw it when i demonstrated it when i took my MPC4k to you

when i press start, the step sequencer doesn’t start
when i press stop, the step sequencer doesn’t stop (but the tempo drops)

(same thing with my new MPC X)

step sequencer starts when you engage int clk button, so how can you test (MIDI start/stop/continue)?

indeed, SSP picks up the tempo -after a while (its a bit better with the X than the 4000)
but no sync start/stop/continue
-why even drop the tempo when (external) sequencer stops?
(why not stay at last tempo received, cause that is likely next tempo anyway)

The step sequencer does not react to midi start/stop yet. Only to midi clock. So I need to add code to make it start and stop on midi start/stop messages, and maybe I have to add midi continue too (?) in the process.

The midi clock controls the internal clock, when midi sync is enabled, so the internal clock has to be enabled. If you turn the internal clock off then you can feed a clock into the clock input of the step sequencer. In that case midi sync won’t work, just FYI.

the midi clock goes through the same tempo estimator as used for the TAP button and that is why it reacts the way it does. I’ll already said I would change this when I have time. After that it will pick up instantly and I’ll make it stick even if the clock isn’t there anymore.

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