CV-clock start/stop and 48ppq

[seanac]

Official topics in the Potential future feature Forum:

• 48ppq clock: viewtopic.php?t=213
• start/stop: viewtopic.php?t=210

Feel free to still write here in this topic for debates or larger discussions around the feature.

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Hi,

The current feature set looks great. I just have two suggestions relating to CV:

1) Possibility to adjust CV clock from 1ppq to 24ppq

Increase this to 48ppq if possible?

2) Add an option to output a constant pulse (square wave) on one of the CV outputs and/or the headphone/line out. I for one would likely never use the built in metronome - so a nice use of the line-out.

Why? This is useful for triggering eurorack-clock/sequencers which accept a RUN signal separate from clock to play, such as Pamela's New Workout. This enables them to always stay lined up (start on 1st beat if stopped/reset).

Triggering Reset would stop this pulse momentarily and then play it again.

[Simon]

Thanks for writing seanac!

1) 48ppq should be easy

2) You are going to have to describe a bit more here. If you use the CV output in "DIN" mode (sync24), it outputs correct DIN sync signal, i.e. square wave at 24ppq on tip (left), and start/stop signal on ring (right). The start/stop signal is basically 0V for stop and 5V for start, it will be set to on/off when pressing the start button. See more info on wikipedia: https://en.wikipedia.org/wiki/DIN_sync
Would that work with your setup?

[seanac]

Yes I believe so!

In the video it looks like you can output two different clocks (divisions) via the CV simultaneously. Super useful!

Being able to route the start/stop signal to the audio out and keeping this functionality would be a great bonus.

Ideal for me:

cv tip: 24-48ppq
cv ring: 1-48ppq (independent from rate of tip) OR 0-5V stop/start
Line out: 0-5V stop/start OR metronome



(If it complicates the setup menu too much maybe just being able to switch from 24 to 48 in DIN-mode. Korg uses 48 so maybe call it that.. )

[Simon]

Are you saying that have a Korg machine that needs 48ppq on one line and start/stop on the other?

What do you think of this:
cv tip: 0-48ppq OR start/stop 0-5V
cv ring: 0-48ppq OR start/stop 0-5V (independent from tip)

Put the start/stop on the Line out might be difficult, right now it's an audio output, so it is always centred around 0V (coupled).

I could potentially add
Line out: Metronome or 2.5V pulses at 0-48ppq

[seanac]

Are you saying that have a Korg machine that needs 48ppq on one line and start/stop on the other?

Korg generally run 48. Not sure about start/stop signal. But my Pamela’s new workout and other euro-sequencers run like you describe (2 mono inputs but a splitter solves that).

What do you think of this:
cv tip: 0-48ppq OR start/stop 0-5V
cv ring: 0-48ppq OR start/stop 0-5V (independent from tip)

Great!

Put the start/stop on the Line out might be difficult, right now it's an audio output, so it is always centred around 0V (coupled).

Ah of course. I’m so used to dc-coupled interfaces I didn’t think of that.

I could potentially add
Line out: Metronome or 2.5V pulses at 0-48ppq

Yes!

[masi]

Many analog synths and controllers (eg by Arturia or Behringer) use a TRS with a pulse signal (up to 48ppq) and start/stop signal. Cannot say offhand which signal is on tip and wich on ring. Usually the jack is labelled "sync" or "sync in". Sometimes it is only a TS jack with pulse only.

DIN sync (with a DIN socket) is rare, but the TS/TRS equivalent is common.

For Eurorack either a dual pulse or a start/stop signal is useful. Though the pulse could be either a trigger signal (short) or a gate (long, 50% of rate for a square wave).

Masi

[masi]

I could potentially add
Line out: Metronome or 2.5V pulses at 0-48ppq

Or abusing it as a not so slow LFO due to the AC coupling. But as we're talking audio rate I cannot think of a an application where I'd need a tempo synced LFO at that speed.

Masi

[Simon]

For Eurorack either a dual pulse or a start/stop signal is useful.

Could you precise what you mean by start/stop signal? Do you mean the same signal as the one on the ring in the DIN sync spec ("Ring | start/stop | stop = 0 volt, start = +5 volt" as explained on https://en.wikipedia.org/wiki/DIN_sync )?

Though the pulse could be either a trigger signal (short) or a gate (long, 50% of rate for a square wave).

And when you say a "gate" at 50% rate:
* say we are sending at 4ppq at 125BPM
* that's one pulse every 120ms
* a "pulse" would be f.x. 5ms at 5V, followed by 115ms at 0V
* but you would want an option to have 60ms at 5V and 60ms at 0V

correct?

Simon

PS: love the idea of the LFO! I did not think about that, it could easily be implemented (it would run from the Metronome output) - I'll definitely keep it in mind! If it is important to you, please create a separate topic for it.

[masi]

For Eurorack either a dual pulse or a start/stop signal is useful.

Could you precise what you mean by start/stop signal? Do you mean the same signal as the one on the ring in the DIN sync spec ("Ring | start/stop | stop = 0 volt, start = +5 volt" as explained on https://en.wikipedia.org/wiki/DIN_sync )?

No and yes. Only a few Eurorack sequencers have decicated start/stop trigger inputs. And if they have, they are separate jacks.

But many if not all have a reset trigger and triggers usually work well with +5V. So on start a trigger must be sent to keep the start of sequence in sync, nothing is required on stop.

OTOH I don't think that any module will wait for the falling edge of the trigger. So simply raising the voltage on start as with DIN sync, will be fine.

Though the pulse could be either a trigger signal (short) or a gate (long, 50% of rate for a square wave).

And when you say a "gate" at 50% rate:
* say we are sending at 4ppq at 125BPM
* that's one pulse every 120ms
* a "pulse" would be f.x. 5ms at 5V, followed by 115ms at 0V
* but you would want an option to have 60ms at 5V and 60ms at 0V

correct?

Exactly. The idea is that you have eg 5V on beats 1 and 3, and 0V on beats 2 and 4.

You can spin that further by changing the relation to eg 3 to 1: so you have 5V for beats 1 to 3, but 0V for beat 4.
Or you could invert the signal, so that it starts with 0V.

Why all this? So you can mangle the signals in the rack with logic modules to derive rhythms. You could do that without Midronome of course. But starting out with a more complex pattern to begin with makes things easier in the rack (less modules needed).

[synchromesh]

Hi, on the subject of different sync formats, I gather the Korg Volcas, the Korg NTS-1 and the Teenage Engineering Pocket Operators have their own sync format, which is one-twelfth of the MIDI sync rate (based on this blog post). No start-stop signal though.

I'm assuming the Midronome can support this - Simon, can you explain how this could best be achieved currently (e.g. via the metronome for output)?

[Simon]

I would need to do some investigating to be 100% certain, but I am pretty sure all those devices will work witha 0->5V analog clock?
If so the Midronome has a "Anlg" TRS output which can output a clock between 1ppq and 24ppq, then this should work
Simon

[thetechnobear]

Just got my Midronome - yay... looks like a fantastic product !


so one question, or possible feature request... for use with eurorack.

many eurorack sequencers will required two inputs (so 2 outputs from midronome).
essentially, one is the clock ( so as we can do with An1/2), the other is a run/reset signal.

so what Id like to do is use An1 as clock ppqn, and the An2 as this run/play signal.

different sequencers have different requirements for this, however, I think the two most common are...


type 1 - clk + play/stop
here the an2 signal is high for play and low for stop

type 2 - clk + reset
here an2 = trig to indicate a reset.
(used where the module doesnt have a concept of transport, and its just a sync)

there are various other combos but these are the most common I think.

one thing that is common, is that the clock is often always sent (on An1).
this is so that the tempo does not have to be calculated when we actually play the transport.

I don't think this is possible currently looking at the manual , but perhaps Ive missed something?


anyway thanks for a great product!

[Simon]

Hey there, thanks for sharing, this is great to know

For now you can try the DIN Sync mode which gives you a start/stop (type 1) and 24ppq pulses.
Type 2 is not really possible with the current features.

But that would be great to implement - see this topic which discusses similar possibilities (but not the type 2): viewtopic.php?t=66

Simon