USB Noise issue. Is this normal? (TI2 Desktop)

  • Hi!

    I have a question regarding output noise through USB.

    I made a quick recording to demonstrate the issue.


    The first one is 3 notes played on a factory preset, the 2nd is the same preset and notes with really heavy limiting (OTT free version default setting but it happens with distortion plugins, etc..so basically with gain).

    The 3rd is some free vst playing the same notes and processed with the same limiter/same settings (just to check it's not the fx chain).


    The noise issue can be heard in the second take when the sound starts fading out. It sounds like a SNR/conversion problem to me and don't know if it's normal or not.
    I live with this for years, only now I had the time/courage/whatever to post about it..

    I appreciate any help!

    Thanks!

  • wellcometoale

    Changed the title of the thread from “USB Noise issue. Is this normal?” to “USB Noise issue. Is this normal? (TI2 Desktop)”.
  • Please let us know which Factory preset, so we can repeat the test on our own systems.


    I assume this is normal, since you're adding probably over 40 dB of gain and start to hear the quantisation errors of the very low volume signal in the release tail. You can do a similar test and record your Virus at a very very low volume, and then boost the audio in your DAW. You will hear and see a very degraded signal with lots of quantisation artefacts.


    I am pretty sure you can get the same result with any synth or pluging if your release tail is long enough and with very low volume.

    Bass Player and Synthesist.
    Virus TI2 Darkstar | Virus TI2 Desktop | Moog Sub 37 | Blofeld | Machinedrum | Monomachine | Analog Four | Digitone | MPC Live | NI Maschine
    Mac OS X 10.14.6 (Mojave) | Cubase Pro 10.5 | Ableton Live 9.6 | Logic 10.4 | MainStage 3.4 | NI Komplete 12 | RME Fireface UFX+

  • Thanks for the reply!
    I don't think it's the matter of the patch. More likely, as you also mentioned, it's related to the high added gain to a low incoming (digitally gain controlled) signal. With my very basic knowledge in digital signals I 'know' that volume and bit depth are in a relation.
    This is why I recorded the same 'melody' with the default patch of a free vsti with the same plugin and same extreme added gain/compression. (see the 3rd part of the soundcloud link).
    I consider them as similar sources (sound generated by program code), so similar behavior expected, but the vst doesn't make those artifacts. (But I'll do another test with longer releases, etc..)


    At the moment I suspect it's the TI. I just want to be sure if it's by design or I have some dried out capacitors, faulty converter or anything like that.


    No matter what, I am infected with the 'virus virus' for a little bit more than a decade and I am quite happy with that..:D

    p.s. As i am writing this something came to my mind. I am using the virus with the VC..wondering if those noises are related to that.

  • for anybody in doubt about my sanity (including myself:D) i did another take with the vst.

    it's the same patch, same OTT default setting. The note was sustaining all the way until the very distorted part.
    I manually tweaked the output gain of the vst synth and at some points I increased/decreased the amount of limiting with the mouse during the recording. At the very end I pasted a normalized version of the "silent" part. Which is the synth turned almost all the way down, OTT bypassed. So there is noise but a very different kind of noise.
    I am also doing another take with the virus. Default init patch, OSC balance turned to OSC1 only. So a basic sawtooth. I am literally waiting for the reverb to end...for like 10 minutes now :D
    Is the reverb infinite when the decay is maxed? :D

  • Sitting too long periods of time in front of a computer and tweaking makes you deaf and dumb, you know. You tend to lose perspective on things. Meaning, yes your sanity has gone next to non-existent. Eventually you start seeing things that are not really there. Luls.

  • ..i did a new take, finally it speaks for itself


    so..two synths, set to play single sawtooth..i placed a plate reverb on the vst synth, used the onboard reverb on the virus.
    copied the same midi part (1/4 beat C2) to all instances
    1 & 2 are the virus without and with the limiting
    3 & 4 are the vst synth + reverb channel, same order
    I am running cubase 9.5 @ 44.1khz on windows 10.
    USB connection is stable.
    TI OS 5.1.7
    annoyingorange.jpg


  • ah... you're using the Virus Reverb?
    Why not switch the Reverb off in the Virus' preset, and extend the release time to a large value to check whether it still produces artifacts?

    Bass Player and Synthesist.
    Virus TI2 Darkstar | Virus TI2 Desktop | Moog Sub 37 | Blofeld | Machinedrum | Monomachine | Analog Four | Digitone | MPC Live | NI Maschine
    Mac OS X 10.14.6 (Mojave) | Cubase Pro 10.5 | Ableton Live 9.6 | Logic 10.4 | MainStage 3.4 | NI Komplete 12 | RME Fireface UFX+

  • ah... you're using the Virus Reverb?
    Why not switch the Reverb off in the Virus' preset, and extend the release time to a large value to check whether it still produces artifacts?

    wow guys,please don't get me wrong but you're both really tough :D


    Oli you were right in your first comment. This issue is related to digital signal behavior and it occurs when serious gain is added to a low level signal from the virus. e.g.: Distortion on tails or modulated volume/filter.
    As my recordings demonstrate: a randomly picked combination of plugins aren't producing such artifacts.

    Feel free to teach me any new methods you think I already don't know. You'll be my guest for a beer if you succeed :)
    ..I am a former audio/music professional currently on 'holiday', so I know what I know and also what I don't (i am not a DSP programmer) :)
    I have a feeling that you assume I want to make the virus seem a bad synth which is totally not the situation here. I am a huge fan of this synth and I am using this exact TI2 for 6 years now and i had two others before. (a snow and a C)
    I just want to know if it's the fault of my very piece of synth or is it normal behavior.
    I am living with this artifact for years now, only now I decided to come here to ask (assuming this is the best place:D).


    So please PLEASE PLEASE, could you or someone else do a little favor to me and for the community and make a test with a simple saw with a long tail\release\volume or filter modulation you decide. The simplest are the reverb or the long amp release.
    Insert some heavy limiting after the signal of the TI and see what happens . I recommend OTT, because it's free and produces the artifact (at least for me) with the default preset. I personally don't recommend and using that plugin for anything, but demonstrating with izotope trash (which I use a lot for sound design) would be more difficult as by default that's doing nothing with the signal and it's not free.

    and to answer your non-relevant question: i like the reverb on the virus and it wasn't cheap and doesn't eat my CPU :D

    I hope I made everything clear about the purpose of this topic now.:D

    ..with manly hugs :D
    Attila










  • I have a feeling that you assume I want to make the virus seem a bad synth

    No. But by not providing the information we ask, you seem not to be willing to help us to help you.


    and to answer your non-relevant question: i like the reverb on the virus and it wasn't cheap and doesn't eat my CPU :D

    The question is very relevant, and if you had invested a little bit of energy, you would have found the solution right after trying my suggestion.


    Anyway, I just tried this on my Virus TI in Cubase:

    1. OTT on the Virus TI audio in with default settings
    2. Play a sound with two sine waves two octaves apart (= no other overtones) with a very long release.
      Result: No audible artefacts at all (at least not at my normal listening levels)
    3. Play a short percussive sound two square waves two octaves apart (loads of overtones) with a short release BUT into the Reverb (Large Room, -2.75dB, Decay 103)
      Result: Lots of noisy artefacts in the reverb tail, exactly as you recorded.


    So what's your professional conclusion?

    Bass Player and Synthesist.
    Virus TI2 Darkstar | Virus TI2 Desktop | Moog Sub 37 | Blofeld | Machinedrum | Monomachine | Analog Four | Digitone | MPC Live | NI Maschine
    Mac OS X 10.14.6 (Mojave) | Cubase Pro 10.5 | Ableton Live 9.6 | Logic 10.4 | MainStage 3.4 | NI Komplete 12 | RME Fireface UFX+

  • I did the test with the sinewaves. (1 osc, 2 notes, decay at 2 o'clockish.)
    Hear it for yourself: OTT first, dry second.


    Hm. There's some distortion going on. Even at the very beginning of the sound.

    Where does that come from?

    Bass Player and Synthesist.
    Virus TI2 Darkstar | Virus TI2 Desktop | Moog Sub 37 | Blofeld | Machinedrum | Monomachine | Analog Four | Digitone | MPC Live | NI Maschine
    Mac OS X 10.14.6 (Mojave) | Cubase Pro 10.5 | Ableton Live 9.6 | Logic 10.4 | MainStage 3.4 | NI Komplete 12 | RME Fireface UFX+

  • The distorted transient might be caused by the punch knob turned all the way up (or halfway) by default.
    All my tests were done using the USB out 1-2
    I haven't tested the analog outs and the SPDIF regarding this issue, otherwise they are working and the everything seems to be fine until I start working with the virus's signal.

    My guesses:
    - it's the virus (design flaw, faulty hardware component, other)
    - it's some kind of clocking/sample rate/driver related problem
    Windows 10 (saying that I am fully satisfied with it's audio handling would be a lie)
    System sample rate: 44.1, project 44.1/24bit






  • So okiedokie, I downloaded the OTT and was able to reproduce the artefacts / "bugging". Its has really nothing to do with Virus TI, just plain and simple output levels. <- the reason why a different vst might not produce the artefacts and the virus will, or via versa. They differ and it seems OTT is particularly "sensitive" to that, youll need just a tiny nugde of too much input gain, and the thing will flip and starts to produce really annoying sounding artefacts. This will happen regardless from what you input to the OTT. Even a rendered "perfect" 256 samples long sinewave did the same thing (and there really is not any "noise" etc in that) , so its not USB noise nor any of the suggested above.


    Just adjust the input gain from the OTT to more suitable level, and you are free from the artefacts (play your stuff at full velocity and adjust the input gain from OTT until the artefacts are gone)

    Now, thers more weirdness to the OTT and regarding midi velocities, it is a really weird plugin have to say that. Only other FX I could get similar artefacts was a distortion ?( with insane amount of gain, I had to use several plugins to crank it up enough.

    Hope that helps.

  • Oh yeah, another thing is that the OTT seems to try to sustain high frequencies to oblivion and beyond. So only needs a "click" at start with too much velocity (or gain) and it will continue to produce those artefacts even without any input, a just key pressed. But I quess thats a feature, working as intended and not a bug.

  • As far as I can figure it out, its just the insane amount of gain. If you happen to introduce ANY tiny bit of noise etc. you will get really ugly sounding artefacts. So the gain knobs are your friends after all. OTT does not seem to be any ordinary compressor / expander, not sure if it was originally meant as a distortion stomp box ^^