Popping noise when retriggering the samples

Dear friends,

Somebody mentioned in the forums that it is not possible to create short sustain loops in Variphrase without glitches. My experience tells that this is not true. To avoid glitches one must find the zero crossing points at each end of the loop. It works even if the loop is as short as a single cycle of the waveform (in that case you get a sustain sound close to a sine wave).

For those who want to create smooth loops for longer parts of the sample here is a link to an old SOS article, which explains how to use software editing tools to create perfectly looping sound material: http://www.soundonsound.com/sos/1996_articles/oct96/sampleloops.html
Even though we might use different software or hardware tools, the basic idea remains the same – create copies of the sample, use the fade in/out function, mix it, and cut it. Thanks to the graphical interface this is fast and convenient. No more cries about the loopcrossfade.

By the way, I still hope to receive some feedback to my previous post. This is a serious issue, and I hope somebody could provide a solution. Otherwise I have to accept that I cannot play monophonic samples with a sustain pedal because of the noise. What a shame for a high-end piece of gear.

Regards,
Raimonds

If you get clicking when triggering, use an attack value in single figures, this will fade it in.

LIkewise for the release.

Thank you for your kind reply, gilesjuk. It seems that the VariOS does not offer conventional envelope controls (attack, sustain, decay, release), but it has amplitude fade in/out function, which I tried. Unfortunately it works in a different way and does not solve the problem.

I will see if it is possible get the desired result with the help of the effects section or by using the LFO. Otherwise it seems that I have run out of tools to solve this noise issue. Input and ideas from other users are still welcome.

Best wishes,
Raimonds

This may be rehashing what the other poster had just mentioned, but anyway....

I'm using a XT and the envelopes are really a fundemental part of the machine for getting samples to behave. On one hit samples (or unlooped sounds) that have any pops/clicks the envelopes can get them easily under control. Without any ADSR control it would be less than half the machine.

Also, clicks can become a big problem (specially with variphrased loops, as the loop points can change to fit the variphrase-slices). So with sustained sounds (pads, strings or even a looping saw wave) it can be a little bit of hit or miss and as the sound is popping within the loop itself. It's impossible to remove these with the envelopes. Luckily though you will not get these clicks if you simply turn variphrase off (as long as it's looping cleaning in the editing window of course), and often with these sort of sounds can work very well without variphrase anyway.

Please keep in mind I have never spent any time with the VariOS and I am talking about the XT here.

Hope that helps.

http://www.soundclick.com/bands/pagemusic.cfm?bandID=87078 For a few Synth and Sound design demos.

Dear Hollowcell,

Thank you for your input. I must admit that in comparison to V-synth, VariOS is very limited in tools that are offered to work with samples. It does not have ADSR controls (except the fade in/out function). Neither can be the Variphrase function turned off. The sample is Variphrase encoded once it is loaded to the instrument. (Please correct me on the above points if I am mistaken).

All signs show that I will need to upgrade to V-synth some day. The only thing, which I lack on V-synth in comparison to VariOS, is the V-producer. Besides, the VA emulations are nice. I have heard that this is just the analog modelling section of the V-synth. But it offers retro interface not found on the V-synth (like the tb303 style sequencing, for example).

By the way, Jim Stout once said that the VariOS and V-synth have the same chip. So theoretically it is possible to write the V-synth software for the VariOS. Then my problems would be solved. Please, Japan, make it happen! ))

Not having ADSR controls is a pitty, but I guess you have to deal with what you've got in this situation. I have to admit that it was the controls of the V-Synth which attracted me. The VP9000/VariOS got my attention, but just having so much hands on sold me.

By "turning Variphrase off" I mean that after you encode the sample/waveform (usually in solo mode hopefully), you simply turn the Variphrase switch off so it reacts like a normal sampler. Sometimes the way Variphrase moves the start/end points of perfectly looped waveforms really introduces horrible artifacts. I often won't use Variphrase when creating sounds, unless they are rythmic loops or sounds which need time control, or they are sounds that need some formant bending . Of course this is what I use it for personaly - everybody seems to have different uses for these machines it seems.

As far as the VA stuff goes on the V-Synth, I really don't touch it very much at all. Although it's very straight forward to program it's no where near as much fun as loading in your own waveforms. Maybe if it had the 303/Jupiter of the VariOS I'd play with it more. Usually for subractive tasks my other gear is what I turn to more.

Well let's hope they decide to include envelopes for the VariOS for all the users out there.

http://www.soundclick.com/bands/pagemusic.cfm?bandID=87078 For a few Synth and Sound design demos.

On Wednesday, 13 September 2006, 00:17 GMT Hollowcell wrote:

>> By "turning Variphrase off" I mean that after you encode the sample/waveform (usually in solo mode hopefully), you simply turn the Variphrase switch off so it reacts like a normal sampler. [...]


I did not find this functionality on VariOS. Maybe I should dig deeper in the manual… Perhaps other VariOS users have something to say about this?

Okay so it's a Solo encoded sample on a VariOS?

If you look at the sample settings- (click on the sample and switch from scope view to sample view) What sort of triger are you using? Is it on loop, gate or retrigger? Toogle through these.

Is it a bassey pop or high frequency? If its basey try adjusting the time variant or changing when the time variant is set (if that makes sense). If its higher frequency then...

Some sounds seem to have shifting harmonics so don't seem as suited to work as a Solo samples. You could recode or resample the file as a backing or ensemble sample. You lose "formant" etc by doing this...

Dear LoS,

Thanks for your contribution to this thread.

I have discovered that the noise appears with all types of encoding and with all samples, I am afraid. The sample settings are provided below.

Sample mode:
- Key assign = Solo
- Play back = Retrigger

Advanced mode:
- Trigger = Gate
- Loop = On (but could as well be Off)

I am not sure what you meant with the "time variant" in your previous post. Is it the “time control” or something else?

In order to understand what I am complaining about, you may try it your own:
1.) Make the sample settings as described above.
2.) Play a note.
3.) While holding the first key down, press a second key.

If the second key cancelled (cut) the previous note and retriggered the sample, it is likely that you heard a clicking noise at this moment. You might quickly and repeatedly press the second key while holding the first key down, and it is clicking all the time. You can achieve the same results also by holding the sustain pedal and playing single notes.

If you use playable samples (like the piano) you might be interested in the following experiment, too. Change the key assign to Poly. Hold down the sustain pedal and play arpeggios or just stack many notes together. You will again here clicking noise as soon as you run out of polyphony.

It is worth mentioning that the noise problem occurs only with the samples set to retrigger mode. If the sample is set to time sync then you hear it seamlessly transposing to different keys and playing legato till the end of the phrase. Apparently there is no problem because the sample is not cut off.

I would kindly suggest that you try it on your instrument, and it would be very interesting to receive some feedback.

I know you are asking about the VariOS, but just out of interest I tried setting things up the way you described on the XT and there was no audible "clicking/popping" that I could make out. I didn't have a heap of time today to test out different sorts of sounds, but tomorrow I will try a range of material.

http://www.soundclick.com/bands/pagemusic.cfm?bandID=87078 For a few Synth and Sound design demos.

Thanks for checking it, Hollowcell. You said in one of the previous posts that XT has sample envelopes including the release parameter. In that case it might be that when you cut off the previous instance of the sample, it ends with the specified release. Or at least it halts the previous sample at the zero crossing point. This is my guess, because different samplers have different designs. For example, AKAI samplers used “sample crossfade” in order to avoid similar problems.

On VariOS, however, there is no release (or crossfade function for that matter). The sample just stops sounding. If it happens to be at the zero crossing point, there is no noise. However it is more likely that it is halted in a different phase, which results in the noise that can be heard. The next instance of the sample obviously starts with zero amplitude and hence there is no way they could match.

This is my theory, which might or might not be correct. So thank you for all the feedback. I also wanted to re-emphasize that the problem occurs only if the next keystroke cancels the previous one. There is no click if I just play one key and release it, or if the next key is being played after the previous key is released.

OK, put a little more time into it today...

I played with a range of sounds from bass, saw leads, pads/strings and loops - all with no release, full decay/sustain and full speed attack. I put the XT into retrigger and mono modes, then played sounds with no portamento and switched between legato on/off. I always held a key before pressing another too.

The verdict: For the most part there was no audible clicks and pops at all. On a few sounds though there seemed to something along the lines of what you mentioned, but it was so small that it was hard to pick up (even with headphones). Seems as if there may be a difference with the way the VariOS and XT deal with samples. Either that, or different material causes different glitches.


http://www.soundclick.com/bands/pagemusic.cfm?bandID=87078 For a few Synth and Sound design demos.

Thanks for devoting your time, Hollowcell. The glitches are less noticeable for sounds with a percussive or noisy attack. On some samples and loops you might also be lucky to press the key at a “silent” moment. In that case there is no click at all.

As concerns the difference in treating the samples, by now it is clear that each of the instruments has different set of tools to manipulate samples (at least different names given). But it is not clear whether there are any fundamental differences in treating samples.

It is said that both instruments have the same chip. Perhaps the noise issue is there because the developers of VariOS created it for manipulating phrases rather than for playing monobass or other mono samples. So it might be that this aspect was neglected or not tested when writing the software.

Maybe I should create some audio demos to illustrate my point. Perhaps it would aslo be a good idea to contact Roland tech support for help. Just have to find the time for that.

Dear friends,

Perhaps somebody could provide additional feedback to this thread. Response from VariOS users is especially welcome.

If you do not want to read all the previous posts, here is a small recap. It appears that VariOS makes unwanted clipping noise when retriggering samples. You may come across this issue with all samples, but it is more noticeable with “playable” things like bass, pads and pianos. Here are the details about the settings:

Encoding: any encoding

Sample mode:
- Key assign = Solo
- Play back = Retrigger

Advanced mode:
- Trigger = Gate
- Loop = On (but could as well be Off)


In order to understand what the problem is about, you may try it your own:
1.) Make the sample settings as described above.
2.) Play a note.
3.) While holding the first key down, press a second key.

If the second key cancelled (cut) the previous note and retriggered the sample, it is likely that you heard a clicking noise at this moment. You might quickly and repeatedly press the second key while holding the first key down, and it is clicking all the time. You can achieve the same results also by holding the sustain pedal and playing single notes.

If you use playable samples (like the piano) you might be interested in the following experiment, too. Change the key assign to Poly. Hold down the sustain pedal and play arpeggios or repeatedly stack many notes together. You will again here clicking noise as soon as you run out of polyphony.

Anyone knows how to solve this?

It is worth mentioning that the noise problem occurs only with the samples set to retrigger mode. If the sample is set to time sync then you hear it seamlessly transposing to different keys and playing legato till the end of the phrase. Apparently there is no problem because the sample is not cut off.

Thanks for devoting you time to read this message, and thank you in advance for your contribution to this thread!