LogicX, Mojave - Clicks/pops and arps

  • Hi there!

    After consigning my Virus TI Pølar to the cupboard for many years, I recently got it out again. I must say I've missed its sound. It really is a synth with something special about it. Why Access cannot develop it further (even with better connectivity to modern systems) is a shame.

    However, there's always the other side... I never managed to get TI to work properly with my setup. I've had better times over the years and worse ones. Right now it is (touch wood) working quite well. I have it attached to a Caldigit TB3 hub and it is on it's own USB 3.1 bus. The thing that I just cannot seem to fix are a few random pops/crackles. These are sporadic and not too bad. The other involves playing arp patterns with delays. Every now and again the arp looses sync, the delay wobbles and obviously resynchronises. Some years ago, Access kindly changed the mainboard in an effort to fix this, but alas the problem still happens. I have tried everything I can think of:

    • This is repeatable on a MPB 2017 15", A MacPro 2008 tower and a 2011 iMac,
    • The MBP is on 10.14.6 LogicX 10.5.1 (Last version to work on Mojave),
    • Tried many USB cables (5 ones I have here) same deal,
    • Tried using Virus as the core audio device, and my Fireface UFX, same result,
    • Tried outputting a spdif from RME to a CO2 converter and then coax spdif to virus to "help" clocking,
    • Use Ableton Live 11, same.

    I guess my question is, is it really possible to get perfection here. Does anyone ever get consistent, reliable audio transmission all the time? I mean, if I knew for a fact it was the hardware I would consider coughing up and getting a Darkstar TI2. But I have gone through many many threads here and there still appears that some people get trouble on the newer models. I also know there's many who have understandably given up, and gone hardware only or use MI editor etc. That is an option, but I kinda love having the TI editor/librarian and am happy to keep my laptop running Mojave just for the purpose.

    In my unscientific approach, I somewhat doubt that "perfect" operation is possible all the time. Maybe some don't notice some of the clicks, or some sounds don't rely on arps and delays all the time. Maybe I'm wrong here, maybe I truly have a dud and always have. The thing is, it's always seemed to work fine as a hardware synth which leads me to believe it's a clocking issue. Either USB transmission, or a mismatch between Logic sending a clock and the TI receiving it. The TI does behave better when it is receiving playback from the sequencer rather than live input but it still happens. I've considered buying a ridiculously expensive USB cable as some audiophiles swear by them. Others say it's snake oil and makes little to no difference...

    Sorry for the long post, I just wanted to get my feelings out and see if anyone else can offer any insight at all. Am I asking for too much here, is the Virus just a flawed diamond that I should give up on, use as hardware and forget the TI, or is it, really, truly possible to fix? Sometimes I just wish I had the money to go out, buy 2 or 3 and just test my theories!

    All the best,


  • Hi again! Answering my own post here!

    Not to be outdone I decided to really go to town and try every last avenue. I have an ancient 2006 MacBook Pro hanging around. It's smashed up and has no battery. The case is bent, dropped etc - you get the picture. Anyways I downloaded the latest/last OS 5 version that worked on Snow Leopard. After what appeared to be an age I got everything setup with Logic 9.

    I wasn't expecting much so I didn't think twice using the visually worst USB cable I had (some old printer thing), loaded it all up, created a patch, added reverb/delay with it clocked as this often induces wobbly arp timing and clicks.

    I played around for a while, tweaked a few things and...no...pops...no...clicks. I mean there was one when it started up but that's standard sometimes. I was like, ohh-kay. What's happening here then! Next I created a simple chord sequence to send to the patch to trigger the arp. I set it on an 8 bar loop and sat back and got hypnotised.

    10 minutes later of various twiddling and actually beginning to enjoy this thing for the first time in over a decade and it was still playing back correctly. I was like WTF!!! This is unbelievable! Next I clicked on the Logic plugin icon to unload the TI plugin. The tail of the sound then clicked and wobbled. I stopped, and played some more notes, clicked the icon again and the clicks came again. It was 100% reproducible. It is like the GUI interaction in Logic was interrupting USB transmission.

    This got me thinking again. On my main laptop with Mojave. Things usually get worse when I tweak knobs. Is this all caused by some interaction with the computer in the background and nothing to do with the Virus???

    Next I reloaded everything back up in Mojave (Virus OS update required again...) and... back to the pops. The thing is, years ago I even went as far as clean installing my Mac to rule out some software interfering and it still happened. Whilst this isn't scientific, in my setup it appears to be caused by an OSX/LogicX interaction with the USB stream.

    How to fix this? I don't think I can. I mean, I could reinstall Mojave again or maybe create a new user account. But it seems to be something deeper with the interruption. I wish Access was more forthcoming with this. I've wasted so so much time over the years as I absolutely love my Virus. I just wish to use it how it's intended.

    IMHO, it is driver related and maybe different computers are more susceptible to this.


    • 3 Macs with OSX Mojave/El Capitan/High Sierra/LogicX = Pitch wobbles with arps & pops/clicks
    • 1 Ancient Mac with Snow Leopard/Logic 9 = almost perfect performance

    I don't know! What gives!

  • Another update, but first off, apologies if these posts are long and arduous. I just hoped to document my research in case anyone else came across the same issues.

    I did some more tests. And I was too hasty to claim victory using an old laptop. What I found is that the Virus is still going out of time but appears to be pitching the arp to adjust for it. Instead of a sudden click/pop when synchronisation is lost, the timing discrepancy is compensated by adjusting pitch. This shoots a hole in my theory that it may have been caused by Logic X. To add to this I boot camped into Windows 10 and installed Ableton 10. Same issue occurs. This all begs the question, is it my Virus? The evidence is mounting that it is. I'm sure this isn't news to many, as I've personally read years of some peoples issues. That's not to say all have an issue, but there's enough anecdotal info to suggest that a fair number do.

    The next thing I asked, is what would cause this. Is it the USB cable/connection. I've tried too many cables and hubs/ports that it's inconceivable that all of these are an issue, across multiple machines and OSes too. Then I came up with the theory that it is a DSP issue. Maybe there is some internal synchronisation issue between the DSPs. As a result I did a timing test, to see how often this happens and it's reproducibility.

    Using a stopwatch and a repeating arp pattern with a reverb/delay clocked to the tempo I recorded when this occurred. On average at 44.1 kHz the clicking/popping happened every 136 seconds. It may have been 134 to 138 to account for my margin of error. At 48 kHz this reduced to about 65 seconds. The interesting thing is that this "clock" is occurring regardless of when anything plays. I say this as when I first play the sequence the timing varies on the first run (as I am catching this timing cycle at various points). From then on it is quite frequent and predictable. I don't believe these numbers are fixed, I think they are dynamic depending on the setup. I also noticed that at times I could initiate more clicks/pops by twisting knobs and adjusting parameters. And that is where I began to feel that this is caused by possible DSP load balancing or a DSP problem, as this is a predictable but also dynamic problem. My TI has always had clicks on the external ins too.

    After all this I got to the point where I've had to finally accept that my Virus is never going to work as reliably as I wish it would in TI mode. For more than a decade I have lived with this pain in the butt problem. I know I'm not the only one, but it still grinds. Moving forward and what to do about it I'm split.

    Should I just keep it and run it as a hardware synth (sensible!)?

    Buy a brand new one/buy another off eBay and compare this issue to determine if mine has a hardware issue or not? If so, cut my losses and use the new one, if it's the same - return it...

  • I never cared much about the "Input" of the Ti. Now I was curious to run sounds through the Virus to "fiddle" around with the Filters.

    And I realied a faint destortion while hacking a few accords in "Static" Input Mode. As soon as I switched to "Dynamic", to get the benefit of the Ti envelopes, all is a mess - not just crackle, but a high destortion at some notes/'chords.

    OK - first thought - "The input signal is too high..." But neither the lowering of the "input" signal of the Ti (Edit Config > Inputs 1/2 > Sensitivity) nor the output of the external signal could solve the issue.

    Therefor, you are right: "After all this I got to the point where I've had to finally accept that my Virus is never going to work as reliably as I wish it would..."

    I wonder if the Ti2 is having the same issue... at least it reads that they have implemented a better CPU.