Beiträge von jim_griff

Hi there. Thought I'd post some random information that's helped me solve my latency issues in the past.

The 'LIVE' button is to reduce the delay so you can play the Virus TI with less latency, but this suppresses the delay compensation when using the Virus Control plugin and will make it go out of time when playing back a project.

You can use the Virus Control plugin as long as you do these things:

1. Optimise BIOS settings. DISABLE all of the CPU power saving states (C1, C3, and all of that.) DISABLE CPU throttling, TurboBoost® and all of that fancy Jazz. You can keep Hyperthreading and all cores active, though.
2. Invest in a dedicated USB 2.0 PCI or PCI-e controller card ONLY for the Virus TI with nothing else plugged into it. I would advise NOT to buy a USB 3.0 card for the Virus TI. I have tested it in different USB 3.0 ports on different systems with the same result; It doesn't like it. Save your money and some time.
3. Buy as short a USB cable as possible. Gold plated conntectors if possible, or just ones that won't tarnish over time. This prevents any connection issues when USB is running in high speed mode.
4. Update to the latest Virus TI OS. I haven't found any bugs with version 5.0.4.02. Some people are still using 4.5.3 due to issues with 4.6.xx and so on, but I upgraded to 5.0.4.02 and haven't looked back!
5. Run some scientific tests by exporting projects with a known reference (see below). Plot down the results on a piece of paper or in notepad. This will be helpful in identifying any latency/timing issues as well as other issues.

Here's one test I just ran on my system, which is specced as follows:

Windows 7 (64bit)
Cubase 7.0.5 (64bit)
Intel 980X Processor 3.46GHz
12GB DDR3 (1333MHz)
MOTU 24i/o audio interface (running ASIO in Cubase)
Adobe Audition 3.0 (best version in my opinion)
Virus TI (OS: 5.0.4.02)
Virus Control VST plugins (64bit) (VST2 and VST3 both tested)

Test conditions: All BIOS, CPU, Windows and Cubase tweaks applied. Short USB cable used. Separate PCI-e USB 2.0 controller card dedicated for Virus TI. Virus Control (2 outputs No inputs). USB 1 output selected for test. P.S. I find that selecting '3 outputs No inputs' can cause more problems with the Virus TI jumping about and not being able to lock onto the project tempo. Maybe this is due to it requiring a little more USB bandwidth.
Test details: 0.5 second audio Dirac spikes on an audio track, panned hard left and used as a solid latency reference. Each synthesizer panned hard right and tested individually using a 1/16 note sawtooth wave played once every 0.5 seconds. Test tempo = 120BPM. Exported/recorded audio files measured in Adobe Audition to check the synthesizer delay or pre-delay compared to the Dirac spikes.

I exported the audio in real-time as well as recording through a separate sound card and got identical results. I compared the latency of the Virus Control plugin (64bit), Virus Control using Arpeggiator, Genesis CM (32bit) plugin and Native Instruments Massive (64bit) plugin.

RESULTS

=====================================
Delay Compensation - Latency Measurements
=====================================
44.1kHz sampling rate / ASIO 128 sample buffer

Virus TI (USB1):
-5 to +6 samples
Compensation required: None

Genesis CM 1.02:
+286 samples OR +6.485ms
Compensation required: -6.49ms

NI Massive:
+33 to +56 samples OR +0.748ms to +1.270ms
Compensation required: -1.01ms (avg.)

I had a feeling that the Virus TI was out of time, as I had problems with it in the past, but it was in fact some of my other plugins. Now I have run some tests using the Dirac spike method, I know which plugins to pre-delay on the channels in the project.

I hope this might be of some help. If not, I'm sorry.

Apologies for resurrecting an old post, but I'd like to add a bit more info. I haven't seen many explanations of some of the various tuning systems out there, so I'll give it a go.

Equal Temperament means that the ratio between the frequencies of any two notes of your choosing will be exactly the same as any other two notes, given that they are the same amount of semitones apart. The ratio between C and D is the same as between G and A - two semitones. Or the ratio between F and G# is the same as between D and F - three semitones. And so on and so forth...

Where 'S' is semitone and 'n' is the note you are working from, the Chromatic scale uses this formula for working out +1 semitone:

S = n * 2^(1/12)
[Semitone equals note times two to the power one over twelve.]

In the above formula, the '2' represents the octave (or doubling of frequency) and the '12' in the denominator is how many equal divisions you want in the octave (twelve notes). The '1' in the numerator represents the single note spacing, or semitone. You could even have this formula for cents: c = n * 2^(1/1200). It's the same deal, just 1200 equal spacings that correspond to the non-linear curve created by the formula. One semitone in that formula would be written as: S = n * 2^(100/1200) which, of course, resolves back down to: S = n * 2^(1/12).

While the Chromatic scale works perfectly, I think some perfectionists probably didn't like the fact that a fifth doesn't resolve to a nice round number. You'd think it would be a multiplication factor of x1.5, but it isn't! It's actually: 2^(7/12) = 1.498307077...

This is so close to 1.5 that I guess people thought they could implement something like Hermode Tuning (called "Pure" tuning on the Virus TI) to keep fifths sounding absolutely perfect as well as major thirds being exactly x1.333r and so on. For Hermode Tuning, 440Hz for middle A will have a fifth of exactly 660Hz instead of it being 659.2551138Hz like it is in the 12-note Equal Temperament scale.

The only unfortunate downside to Hermode tuning is that it skews the mathematical formula. When you shift the fifth of A (or E) across from 659.2551138Hz to 660Hz, this has now essentially shifted the rest of the scale upwards. So now the octave of 440Hz isn't exactly 880Hz but more around ~882Hz... This is a BIG problem for music production. Every single chord now doesn't relate to any other chord in a mathematical or even a musical sense. While an individual chord may sound perfectly in tune and all harmonics of all frequencies are lined up precisely, the next chord you play may sound either too sharp or too flat vs the previous chord.

Here's a list of the multiplication factors for all notes in any octave in the Chromatic (12-note Equal Temperament) scale:

+0 semitone = x1.000000000 (root note)
+1 semitone = x1.059463094
+2 semitone = x1.122462048
+3 semitone = x1.189207115
+4 semitone = x1.25992105
+5 semitone = x1.334839854 (Almost 1.333 recurring, but not quite)
+6 semitone = x1.414213562 (Very interesting number in maths. This EXACT number is used a lot in electrical engineering.)
+7 semitone = x1.498307077 (A fifth. Almost exactly 1.5)
+8 semitone = x1.587401052
+9 semitone = x1.681792831
+10 semitone = x1.781797436
+11 semitone = x1.887748625
+12 semitone = x2.000000000 (octave)

These ratios/multiplication factors are altered for Hermode tuning, which aims to get rid of audible note 'beating' when playing two notes. If you understand anything about two notes being played together, they form a third beat frequency that is a function of the difference between the two frequencies. 440Hz vs 660Hz will have a 220Hz beat frequency. 220Hz divides well into both 440Hz and 660Hz. With the Chromatic scale, however, the beat frequency between 440Hz(A) and 659.2551138Hz(E) is 219.2551138Hz. This frequency will cause audible beating, because it is not mathematically related to either the middle A or the E you are playing. It works great in a musical sense, but people nowadays tend to believe Nature itself is incorrect

EDIT: The edits are for spelling, grammar and styles/formatting purposes only.

Zitat von flabberbob

What TIOS are you currently using?

Hi. I'm using 4.5.3.00. I have had many problems with previous versions, but this one seems the most stable and has sorted out the other issues I was having. I'd attempt an upgrade to 5, but have heard a lot of people were having trouble with the beta. Think I'll wait until it's in a release state before trying to upgrade.

----
EDIT1: My current system and settings are:
PC:
Intel Core i7 3.33GHz Extreme // 12GB RAM // Gigabyte GA-X58A-UD7 (disabled all the CPU power saving as well as TurboBoost®)
Audio:
MOTU 24i/o (Tested at 44.1kHz, 48kHz and tested at 16, 32, 64, 128, 256, 512, 1024, 2048 sample buffers.)
OS:
Windows XP 32bit (tweaked down to 13 background processes, disabled selective suspend, power saving, enabled Windows 3GB switch, etc.)
Sequencer:
From Cubase 5.5.1 to Cubase 6.5.4, the same issue is evident.

Bumping this post, just incase anyone's forgotten about it.

I stopped producing music for a long while due to problems with the Virus TI (my main synth.) Now I am back and trying to make music, but this bug keeps annoying me. It is almost like having an analog synth the way it goes out of tune.

Here's my checklist up to now:
1. Disabled all power saving optimisations in BIOS, Windows and everywhere I can find.
2. Using dedicated PCI-e USB2.0 controller card with a short USB cable to the Virus TI.
3. Invested in power distribution and filtering system (Samson Powerbrite Pro), plus surge protected sockets.
4. Checked the Virus TI with Windows XP 32bit and Windows 7 64bit. Same on both.
5. Checked it with/without USB connection. Without USB connection it is perfect.

Video again: http://www.youtube.com/watch?v=j6KCI-u6A_w
In the video, it makes no difference whether multi-processing is switched on or off. It occurs with both. Simply switching it off and on again causes the Virus TI to become stable for another few seconds - enough time to bounce down a short segment of audio before it starts going out of tune again. I have also checked with only one CPU core active in BIOS, so there's no multi processing or hyperthreading possible. It exhibits the same behaviour.

Thanks, Jim.

Do these things:

1.Go into BIOS and disable ALL power saving features on your CPU. The Virus TI does not like power saving.
2. Disable Intel Turbo Boost. The random clock changes cause weird things to happen in low-latency applications.
3. Use a shorter USB cable if possible.
4. Buy a PCI (or PCI-e) USB2.0 controller card and use that ONLY for your Virus TI
5. Buy surge protection and power filter systems for all your gear
6. Buy some USB power isolating isolator thingies to prevent any ground loop hum from entering your Virus TI via the USB cable. USB power supplies inside computers are connected directly to your house ground and this can cause problems in some cases.

If all these steps fail, you can always contact support. I managed to reduce my crackling problem to a minimum, even though I have a more annoying pitch modulation bug caused by the Virus TI not liking being slaved to an external USB clock. Grrrrr, this thing.

Zitat von HysteriaPsy

Please help !

I solved a few of the latency issues I had by doing these things (recommended by support and other users of the forum):

1. Bought PCI-e USB 2.0 controller card for dedicated connection to the VIrus TI. Wouldn't bother with USB3.0
2. Bought new shorter USB cable
3. Bought a 240V 10A power conditioner for studio hardware to connect to
4. Updated to latest Virus TI OS
5. Updated all PC drivers and installed that multi-cpu hotfix from Microsoft's website ( http://support.microsoft.com/kb/909944/en-us )
6. Tweaked BIOS: Disabled all CPU power saving options (i.e. all that C4, C5, C6 power state crap and the other ones) and Intel TurboBoost®
7. Installed all latest drivers for audio interface
8. Joined several religions and prayed to all the different gods (this one I did without advice)

I solved the latency issues I had and the crackling/popping sound on USB direct audio outputs into Cubase with all of the above 'fixes'.
I still have issues with the detune bug ( http://www.youtube.com/watch?v=j6KCI-u6A_w ) but all else is fine and stable.

I'm guessing you have done most if not all of the above steps to solve your issues, so I will pray to my several gods for you and cross my fingers and toes.

Regards, Jim.

Can someone remove this thread please. I can't find out how to do it.

Thanks.

Zitat von renepaismusic

Bump.
Any ideas? Got no solution from the Support aswell yet, within few weeks..

This used to happen to me all the time. The problem is dodgy RAM no doubt. Once upgraded to Windows 7 64bit, I started to encounter problems with Cubase and the Virus TI with constant blue screens. It is to do with it using parts of the RAM it never accessed before when running at 32 bit.

-- Try downloading and running Memtest86 on a bootable CD. Remove all sticks of RAM and try one at a time and let it do several runs. Then replace and try different sticks of RAM in dual channel mode. Try again with 3 or 6 sticks in triple channel mode (basically all combinations). --

This will probably take you several hours if not days, but you may find an error with a stick of RAM.

It took me two times sending my 6 sticks of RAM back before I finally ended up with Corsair's latest revision of the sticks that were fully tested at the factory. They don't seem to like to test memory straight out of the factory nowadays, so a lot of people have dodgy RAM without realising it.

Hope this helps.

EDIT 1: P.S. I also tried mine on completely different computer with the exact same results and it turned out their computer had faulty RAM too. I wouldn't rule it out completely. It took me days to come up with any errors in Memtest. Also, try running your computer without a page file and just on RAM and see what happens.

Any news on when the detune problem will be fixed or how it is possible to get rid of it? It's driving me crazy at the moment and I'm having to bounce tracks down several times in order to get even half of a decent take.

Zitat von nms

The Ti2 will change nothing of your issues. I agree that pitch drifting really needs to be fixed and shouldn't happen. The pre-delay you mention - is that when using the analog out for that part while still having the VC plugin running in the project?

The 9ms pre-delay is only when using the arpeggiator, and I have only tested it using USB mode directly into an audio channel in Cubase. I've never used the analog outs at the same time as the Virus Control plugin. It only occurs with any OS beyond 4.0.5.01, which is why I'm sticking with this OS version until it's been solved.

If you have Cubase 4 or beyond, you can try this project. Track 1 is single notes running with the click track. Track 2 is the arpeggiator performing the same pattern. There are some images showing the spectral view in Adobe Audition where the predelay is visible. For me, it is 100% replicable and there's no way I can 'nudge' the TI into working correctly with any OS beyond 4.0.5.01.

Zitat von nms

I've had the same thing here on my Ti2 in usb mode. Stabilizes after unplugging usb and using analog outs.

It runs perfectly stable for me through the analog outputs too.

This is why I believe it is a badly designed PLL loop filter and that the global clock of the TI is modulating up and down as it tries to lock to the USB host clock. *hint hint to the engineers*

EDIT: I tried rolling back to the older OS's (3.0. . .) and still have the detune issue. Maybe I didn't notice it before. I did think it was an analog emulation algorithm that was impossible to disable.

Hi. I thought it might be appropriate to create a thread about this before investing in a TI2.

I was wondering if anyone has had the same issues with the TI2 after upgrading from a TI version 1? I would really love to have the additional polyphony that the TI2 offers, but would also hope that the problems I'm having were solved with the upgrade. I have bought a whole new PC, bought a PCI-e USB2.0 card, bought a Power Conditioner, cleaned the USB cable thoroughly, disabled all power saving features in BIOS, tweaked my PC as much as I possible can, but still have issues.

Q1. Has any hardware inside the TI2 been altered to solve issues that the TI1 has? (other than the changes to give it more processing power and polyphony.)

Q2. Has the pitch modulation issue ( see this video ) been solved with any of the hardware changes in the TI2? (i.e. Maybe a change to the PLL chip's loop filter design to make the locking speed quicker so it doesn't modulate all over the place while trying to maintain sync with the PC's USB clock.)

Q3. Will my arpeggios play in time and not have a 9ms pre-delay compared to everything else? ( a big problem I have had since OS 4.1.0.16 and all later OS's - see this rar file. )

Thanks in advance for any information and help.

Zitat von nidefawl

I thought this one was fixed way back in some update

At least I read it in some patch notes.

What tool did you use to display the tuning? I want to have a try on reproducing this issue

It's only since OS4 that I have started to have the detune problem. I did hear they fixed some detune problem in an OS 3 patch, but seems I got unlucky.

I sent the main output from Cubase into another soundcard then used spectral view in Adobe Audition 3.0 to view it.

VIDEO OF THE PROBLEM:
http://www.youtube.com/watch?v=j6KCI-u6A_w

Hi,

I just thought I'd post a new thread to hopefully combine all the other 'detune bug' threads into one. Maybe we can look for possible causes, rather than waiting for Access support to forward the many problems to the engineers and find no solutions after months.

PROBLEM: When the Virus TI is used in USB mode, there is the tendency for the pitch to oscillate up and down slowly. (Aparrently this problem does not occur with Macs.)

MY THEORY: I believe the PLL used to keep the TI's internal clock in sync with the USB port may be buggy or poorly designed. It's just a theory, but after researching a little into electronics, I believe it could be one possible area for the engineers to look at.

The reason I have come to this conclusion is that nothing else could possibly be causing a slow oscillation of the pitch. When the TI is used on its own, the pitch is 100% stable - only when the TI is connected to and has to maintain sync with a host does it exhibit this problem.

[ One workaround in Cubase is to keep changing the ASIO buffer size from any value to any other until you hear the pitch is holding steady. Then you can continue working on your project until it decides to start oscillating the pitch again. ]

EDIT: Video of the problem: http://www.youtube.com/watch?v=j6KCI-u6A_w

The same problem occurs in Cubase when 'emulated' MIDI inputs are used. I'm not sure about Macs and Logic, but with Cubase the solution is to force Cubase to ignore the port filter so you can see the non-emulated inputs. This gets rid of the horrible pre-delayed MIDI problem. Maybe there is a similar option or setting in Logic?

Zitat von horizens

I've been experiencing a lot of crackling with the TI in Ableton running USB and read somewhere to use the VST version instead of AU.

Has this helped anyone else?

The crackling problem occurred for me in Cubase 5 using the VST control for the Virus TI. It occurred primarily on USB stereo output 3, yet seemed fairly nonexistent on USB stereo outs 1 and 2.

I disabled all CPU/Motherboard power saving features in BIOS and this seemed to solve a lot of issues with crackling and buffer underruns.

Hope this helps.

Zitat von AtonyB

Dont think so, its not in device manager, its in the power options in control panel.

Thought I'd take some screenshots , just in case it's called by a different name and I've been staring at it the whole time.

Zitat von AtonyB

I don't have an XP machine any more to give screen shots or remind myself of the precise process. But you definitely do not need to go into the registry editor.

I'm wondering, is Selective Suspend the same as the "Allow the computer to turn off this device to save power" option? Because I disabled all of those on first install.

Zitat von AtonyB

Did you really need to go into the registry? The power options in control panel can get you there...

I'm using Windows XP for music production, so there's no option for Selective Suspend. It has to be done manually, unfortunately.