Two odd / possibly defective behaviors: Do all Trigon-6's do this?

[bamagill]

I am a proud owner of Sequential products for 40 years. I purchased a new Trigon-6 last week, and I am noticing two problems. One is minor/curious, the other I think is more major. I am trying to determine if these are found in all Trigon-6's or just mine:

1.It sounds like pressing the "Sync OSC 2" button puts Oscillators 1 and 2 out of phase with each other. This is not noticeable unless both waves are triangles and OSC 2 is set EXACTLY the same as OSC 1 (same octave, not detuned) in which case OSC 2 drops in volume dramatically, and the heard waveform is very different than what I would expect suggesting phase cancellation. Detuning OSC 2 causes the sound to gradually rise in volume, and picking a different waveform or octave doesn't cause the problem. This is wierd, especially since only the triangle seems to be affected.

2. If the VCA is driven directly from the LFO, Loud clicks/clunks and Thumps are heard from the VCA, even if no signal is going through. This happens with all 6 voices. It's most noticeable if using a Square or Random waveform, and starts at about 40% of LFO "Amount" and gets worse as you go to 100%. This just sounds like the slew rate of the VCA is so fast that it's literally getting slammed up and down by the LFO. just a LITTLE slew would take care of this. If you are using the envelope, you can adjust Attack and any problem like this is easily gotten rid of - but there is no way to do this whenthe LFO is driving the VCA directly. If it take the LFO rate up, I even get a little VCO coming from the VCA. Is this fatal? no, it just eliminates a modulation routing that would have been useful to have.

   If I am the only person experiencing these problems, I will exchange my unit for another and Sequential can see what's wrong with mine. If these are by "design", I would say that's too bad, especially Item 2. Since it's new, "Operator Error" is always possible so I am curious as to what others think.

Thanks,

Brian

[bamagill]

I have discovered that my SN (423) is actually very early and I am way behind on OS updates. That might be the problem. Going to get OS 1.2 and see what that does.

I am a proud owner of Sequential products for 40 years. I purchased a new Trigon-6 last week, and I am noticing two problems. One is minor/curious, the other I think is more major. I am trying to determine if these are found in all Trigon-6's or just mine:

1.It sounds like pressing the "Sync OSC 2" button puts Oscillators 1 and 2 out of phase with each other. This is not noticeable unless both waves are triangles and OSC 2 is set EXACTLY the same as OSC 1 (same octave, not detuned) in which case OSC 2 drops in volume dramatically, and the heard waveform is very different than what I would expect suggesting phase cancellation. Detuning OSC 2 causes the sound to gradually rise in volume, and picking a different waveform or octave doesn't cause the problem. This is wierd, especially since only the triangle seems to be affected.

2. If the VCA is driven directly from the LFO, Loud clicks/clunks and Thumps are heard from the VCA, even if no signal is going through. This happens with all 6 voices. It's most noticeable if using a Square or Random waveform, and starts at about 40% of LFO "Amount" and gets worse as you go to 100%. This just sounds like the slew rate of the VCA is so fast that it's literally getting slammed up and down by the LFO. just a LITTLE slew would take care of this. If you are using the envelope, you can adjust Attack and any problem like this is easily gotten rid of - but there is no way to do this whenthe LFO is driving the VCA directly. If it take the LFO rate up, I even get a little VCO coming from the VCA. Is this fatal? no, it just eliminates a modulation routing that would have been useful to have.

   If I am the only person experiencing these problems, I will exchange my unit for another and Sequential can see what's wrong with mine. If these are by "design", I would say that's too bad, especially Item 2. Since it's new, "Operator Error" is always possible so I am curious as to what others think.

Thanks,

Brian

[bamagill]

All,

         First, there is no OS 1.2, at least not yet. That is a Trigon-6 Manual "Misprint" - my interpretation is that OS 1.2 is not finished/officially announced.

          Second, the clicks I am experiencing are "expected behavior" according to Sequential.  However, I tried the same routing on an OB-6 and the behavior is the same, so it's across the entire Sequential range. While it may be expected, it's not very musically useful, at least to me. I will point out that this happens ONLY if you route the LFO directly to the AMP. If you use Aftertouch or the mod wheel to control the depth, you do not hear this issue.

[synthwave4ever]

Everything is apparently "expected behavior" when you ask Sequential support. lol. That's what I was told several times when a voice on my then-brand new OB 6 was clearly out of calibration despite my running all the calibration steps. Ended up getting them to send me a replacement voice card which fixed the issue, but had I not pushed the issue, I'd have been expected to just deal with it - on a $3000 synth.
Not hating on the Sequential guys. Love the gear and they've been pleasant to deal with... just seems like sometimes they don't take defect reports as seriously as maybe they could.

[KG]

1.It sounds like pressing the "Sync OSC 2" button puts Oscillators 1 and 2 out of phase with each other. This is not noticeable unless both waves are triangles and OSC 2 is set EXACTLY the same as OSC 1 (same octave, not detuned) in which case OSC 2 drops in volume dramatically, and the heard waveform is very different than what I would expect suggesting phase cancellation. Detuning OSC 2 causes the sound to gradually rise in volume, and picking a different waveform or octave doesn't cause the problem. This is wierd, especially since only the triangle seems to be affected.

It must be feature not a bug ;-) since I have same behavior.
And received my Trigon-6 just yesterday.

[KG]

2. If the VCA is driven directly from the LFO, Loud clicks/clunks and Thumps are heard from the VCA, even if no signal is going through. This happens with all 6 voices. It's most noticeable if using a Square or Random waveform, and starts at about 40% of LFO "Amount" and gets worse as you go to 100%. This just sounds like the slew rate of the VCA is so fast that it's literally getting slammed up and down by the LFO. just a LITTLE slew would take care of this. If you are using the envelope, you can adjust Attack and any problem like this is easily gotten rid of - but there is no way to do this whenthe LFO is driving the VCA directly. If it take the LFO rate up, I even get a little VCO coming from the VCA. Is this fatal? no, it just eliminates a modulation routing that would have been useful to have.

I have tried to reproduce this today - depending on frequency of LFO it is clicking or sound.
This problem is largely amplified by Distorion knob.

To recreate this and exclude other possibilities:

1. Recall 'Basic Preset' (hold PRESET and press WRITE button)
2. Turn off all oscillators (you can also turn volume down on all three just to be sure)
3. Set to minimum Cutoff, Resonance and Env. amount for filter (middle position) to prevent it from making any sounds (self-oscillation etc.)
4. Set Sustain of AMP Envelope to maximum, and Attack/Decay/Release to minimum.
5. Turn off all LFO destinations (by default in my case is Freq 1) and turn on AMP as destination. Set Frequency of LFO to maximum, choose Square (but happens also for Sawtooth, random...) shape and amount to maximum.

In this scenario when playing on keyboard I can hear that 2 of 6 voices are very loud, 3 are average and 1 is (almost) silent (just repeat playing same key again and again).
To boost loudness of them turn DISTORTION knob to maximum.

Also some playing with AMP envelope shows that LFO is modulating signal before AMP envelope.
That is why when you set Sustain to minimum no sound comes from Trigon. Or if you set Attack to some larger value mentioned sound comes to maximum slowly.

[The Real MC]

1.It sounds like pressing the "Sync OSC 2" button puts Oscillators 1 and 2 out of phase with each other. This is not noticeable unless both waves are triangles and OSC 2 is set EXACTLY the same as OSC 1 (same octave, not detuned) in which case OSC 2 drops in volume dramatically, and the heard waveform is very different than what I would expect suggesting phase cancellation. Detuning OSC 2 causes the sound to gradually rise in volume, and picking a different waveform or octave doesn't cause the problem. This is wierd, especially since only the triangle seems to be affected.

Understand that all VCOs are free running.  It is possible that tuning two of them in unison with the triangle wave may result in one of them out of phase.  Not a malfunction, it's the nature of the beast.

2. If the VCA is driven directly from the LFO, Loud clicks/clunks and Thumps are heard from the VCA, even if no signal is going through. This happens with all 6 voices. It's most noticeable if using a Square or Random waveform, and starts at about 40% of LFO "Amount" and gets worse as you go to 100%. This just sounds like the slew rate of the VCA is so fast that it's literally getting slammed up and down by the LFO. just a LITTLE slew would take care of this. If you are using the envelope, you can adjust Attack and any problem like this is easily gotten rid of - but there is no way to do this whenthe LFO is driving the VCA directly. If it take the LFO rate up, I even get a little VCO coming from the VCA. Is this fatal? no, it just eliminates a modulation routing that would have been useful to have.

You're hearing control feedthrough of the VCA.  It is not a malfunction, it won't hurt the synth, and it is the nature of the beast.

A full calibration should adjust the VCAs on all voices to minimize the control feedthrough.

[KG]

1.It sounds like pressing the "Sync OSC 2" button puts Oscillators 1 and 2 out of phase with each other. This is not noticeable unless both waves are triangles and OSC 2 is set EXACTLY the same as OSC 1 (same octave, not detuned) in which case OSC 2 drops in volume dramatically, and the heard waveform is very different than what I would expect suggesting phase cancellation. Detuning OSC 2 causes the sound to gradually rise in volume, and picking a different waveform or octave doesn't cause the problem. This is wierd, especially since only the triangle seems to be affected.

Understand that all VCOs are free running.  It is possible that tuning two of them in unison with the triangle wave may result in one of them out of phase.  Not a malfunction, it's the nature of the beast.

No, as OP wrote OSC 1 and OSC 2 are synchronized ("Sync OSC 2" is ON).

I have  taken some outputs in Oscillator plugin in Reaper to visualized that (see first image attached):

1A) only OSC 1 running triangle (OSC 2 turned off)
1B) OSC 1 and OSC 2 running triangle SYNC together - we can see almost perfect signal cancellation (180° phase shift between OSC1 and OSC2)

2A) Square on OSC 1 (OSC 2 turned off)
2B) Square on OSC 1 + OSC 2 (in SYNC)

3A) Sawtooth on OSC 1 (OSC 2 turned off)
3B) And here is interesting case - when you run sawtooth in sync on both oscillators because of phase shift between them you will get twice frequency in result (if they were not shifted you would get amplified sawtooth from 3A)

Explanation for 3B is in second picture attached when you see 'red' and 'blue' sawtooth from oscillators and when they are added together (because being shifted by 180 degrees) it results in 'gray' signal which has twice frequency than base signals.