Analogue sync trigger attenuation/shaping

[amaeland]

Hi, I have noticed that my Korg SQ-1 is pretty unreliable when receiving analogue sync from my Midronome. From time to time it will jump several steps at once. According to user reports on Modwiggler, this sequencer (and others too, apparently) can do this when the sync signal is too strong. Several users reported stable sync after attenuating their sync signal.

Source: https://www.modwiggler.com/forum/viewtopic.php?t=168295

I am going to experiment with making a stable sync signal using my TR-8S drum machine, as I don't have a passive attenuator to stick between the Midronome analogue out and the SQ-1. But if this is a solution for the SQ-1 as well as certain other sequencers, it would definitely be cool if the 'Nomes supported attenuation of the clock pulse!

Perhaps the shape of the pulse itself is a contributing factor, but hopefully the culprit is simply the output level.

[amaeland]

Just discovered this:

"The manual for the SQ-1 was kind of helpful - it says that the output of the Sync jacks is a 15ms, 5VDC blip"

https://cycling74.com/tutorials/soft-ha ... -sequencer

How long is a 'Nome clock pulse?

[amaeland]

Okay, so here's my results from this evening's testing.

DAW generated sync pulse -> D/A -> Korg SQ-1 analogue sync input
Korg SQ-1 CV/Gate -> Behringer TD-3-MO synth

I used a softsynth to create a square wave drone, bounced it and trimmed it to exactly 15 milliseconds. Loaded it as a sample into a software sampler and made a 16th note sequence with it. Adjusted the pulse to hit -0.1 dBFS in the DAW, then routed this it out from the DAW.

There was a ~30 dB (!) window where I could adjust the gain fast up and down without affecting the stability of the clock at all. The range was from -47 to -17 dBFS. As soon as I approached about -15 dBFS, the sequence would stumble. However, it seemed to be stable as long as I did not adjust the gain. A few dB past that though, and the sequence would start stumbling even when I wasn't adjusting the gain up and down.

The 'Nome analogue clock causes the SQ-1 to handle as if I were feeding it a pretty hot clock from the DAW. It trips over maybe once every 5-10 seconds.

The little Korg box is actually wicked if only it stays stable! It would be amazing if the 'Nome had either a continuously or stepped (say 0, -10 and -20 dB) variable attenuation option for the analogue clock.

[Simon]

Hi

Thanks for the long and detailed explanation! 5V DC is very standard for any analog clock, and it's precisely the voltage used by the Nome.

So I do not think "loudness" is the issue. But if you want to attenuate it you can simply get one of those headphones passive volume control, some of them come as a very cheap cable with a slider in the middle. These will attenuate the voltage anywhere between 0 and 5V.

What I believe is the issue is with the time: the Nome pulses are 5ms long, and if the SQ-1 is too slow are processing them, then maybe the pulse is gone before it had time to be processed. If you want I can make you a custom firmware with longer pulses.

What is the behavior when the SQ-1 "trips"? does it get out of sync, behind (=later than) the clock?

PS: I moved the topic to where it belongs

[HappyClocker]

Hi, I have no issues syncing my SQ-1 with the Analog Outputs of my Nome I.

My working settings that run SQ-1 sequencer at the same speed like Nome I:

Nome I: An.1 or An.2 = '4

SQ-1 Global Settings: “=>“ PARALLEL ORDER: quarter note / SYNC X1
(SYNC X1 = 1 sync clock advances 1 step)

Don't ask me why: I had to test various sync settings on Nome and SQ-1 and finally these work.

[Simon]

Very interesting, thank you for sharing! Since you are using both An.1 and An.2, are you using a splitter cable TRS->2xTS and sending this to 2 different inputs on the SQ-1?

[HappyClocker]

Hi, I'm using a cheap splitter cable TRS->2xTS but only one Nome analog output and one TS jack. The second TS jack is unused.

E.G. J&D Airplane Airline Flight Cable for Headphones, 3.5mm 1/8 inch TRS Male to Dual 3.5mm 1/8 inch TS Male Gold Plated Copper Shell Heavy Duty, 3 Feet

Edit: When you google for it you will find several dealers incl. Amazon. Benefit of this cable: Both ends have jacks and no sockets at the TS side.

[amaeland]

Hi

Thanks for the long and detailed explanation! 5V DC is very standard for any analog clock, and it's precisely the voltage used by the Nome.

So I do not think "loudness" is the issue. But if you want to attenuate it you can simply get one of those headphones passive volume control, some of them come as a very cheap cable with a slider in the middle. These will attenuate the voltage anywhere between 0 and 5V.

I have actually already ordered the parts to build a passive attenuator myself. Taking it as a DIY challenge, I want to learn more about electronics so it seemed a nice beginner project

What I believe is the issue is with the time: the Nome pulses are 5ms long, and if the SQ-1 is too slow are processing them, then maybe the pulse is gone before it had time to be processed. If you want I can make you a custom firmware with longer pulses.

wow, that's a very kind suggestion! But let me experiment a little more, maybe I can get things to work without it.

What is the behavior when the SQ-1 "trips"? does it get out of sync, behind (=later than) the clock?

No, it does not get out of sync as such, it just jumps additional step(s), causing the whole sequence to offset while still being on the grid.

Hi, I have no issues syncing my SQ-1 with the Analog Outputs of my Nome I.

My working settings that run SQ-1 sequencer at the same speed like Nome I:

Nome I: An.1 or An.2 = '4

SQ-1 Global Settings: “=>“ PARALLEL ORDER: quarter note / SYNC X1
(SYNC X1 = 1 sync clock advances 1 step)

Don't ask me why: I had to test various sync settings on Nome and SQ-1 and finally these work.

Thanks very much for your input! I tried using these settings just now, but for some reason I am getting 1/32nd notes with the combination of '4 on the Midronome and 16th note sync on the SQ-1 (parallel pingpong order, mode #3 on the sequencer mode knob). I am using a cable splitter. Previously I used An.2 to reset my modular's clock, but I sold my system so only need 1 analogue output at the moment. The second cable isn't connected to anything.

Tried changing the Midronome An.1 1 to '2, and the SQ-1 seems quite stable now. I am starting to suspect my problems might be arising due to PDC issues or something, e.g. when I have a lot of plugins in my project and some of them are introducing latency (maybe due to a master limiter). Logically I suppose this should not be the case. If the SQ-1 is stable from now on I will own you a debt of gratitude!

[HappyClocker]

Hi, You might be still on the wrong "pingpong" mode that Korg calls <=>“ PARALLEL TURN: 16th note / SYNC X2.

My SQ-1 is on “=>“ PARALLEL ORDER: quarter note / SYNC X1

Have look at the section "When I connect the SQ-1 via SYNC to the volca, monotribe, or electribe, the sequencers do not advance
at the same speed." in that document:
https://www.korg.com/us/support/downloa ... /436/2303/

[amaeland]

Hi, You might be still on the wrong "pingpong" mode that Korg calls <=>“ PARALLEL TURN: 16th note / SYNC X2.

My SQ-1 is on “=>“ PARALLEL ORDER: quarter note / SYNC X1

Have look at the section "When I connect the SQ-1 via SYNC to the volca, monotribe, or electribe, the sequencers do not advance
at the same speed." in that document:
https://www.korg.com/us/support/downloa ... /436/2303/

I see! Had a look at the manual but it only seemed to mention the first three modes (and not that 16th notes were SYNC x2). Trying your setting out now

[SeleN]

another sq-1 user here: same settings in sq-1 as happy clocker and no issue here. you have to check this sq-1 page for advanced settings. its not in the manual https://www.korg.com/us/products/dj/sq_1/faq_tips.php