My Virus Ti can't play in time using DIN Midi

Hello, new to the Virus world, and I'm having an odd problem. I have managed to get my TI setup working in ableton, no real issues or problems, great. However - I am getting really bad midi jitter when using the virus with midi via the actual midi connection. The jitter is bad enough that it can almost sound like a sloppy swing setting, very noticeable and essentially makes the virus unusable without using TI.

My test setup is simply 16th notes at 120 bpm being output from a cirklon sequencer. I have turned off all extra data (midi clock etc...). The virus has its own dedicated port with nothing else connected. No swing, velocity at 100, all note lengths at 24 ppq. This should be about the most stable midi anyone could ask for. If I swap the virus for another synth and use the same midi connection, the other synth plays perfectly in time.

The weird thing is that if I use an init patch, in mono mode, with a short amp envelope, the timing is fine. Doing anything that increases the voice count - poly mode, longer amp release times, unison mode etc... are what seem to influence the jitter. More voices = worse timing. I understand that more voices will obviously effect voice stealing etc... but it shouldn't produce sloppy timing.

Also - I can make these same changes to a sound when it is being used in TI mode and the timing stays tight. The more voices = more jitter only happens when using the virus via the midi in jack.

I have some experience doing hardware design, and a bit of experience working on projects with midi, and I can't imagine that this is a physical fault in my unit. The midi data is getting to the processor and is being processed - it just seems to have a lower priority than it should.

Does anyone out there have any ideas of what could be causing this? I couldn't find any other mentions of this issue anywhere, and with the amount of viruses out in the world, I would think it would have been noticed by someone else. I'm on OS 5.1.7 BTW.

Any thoughts on this would be appreciated.

Just did some more testing, I get the same behavior (sloppy timing) in all modes (single, multi, seq) when receiving midi from the "midi in" jack.

Also tested this with an mpc live providing the midi sequencing and get the same sloppy timing/jitter.

Also tried swapping the midi cable. No difference.

Zitat von oliAtBass

MPC Live is the synonym for sloppy timing and jitter ... according to some opinions on the interwebs
Seriously, I've never tried a setup like that, but wanted to use my Live for exactly that purpose somewhere in the future.

Are you sending a monophonic line or chords? If it happens already with a monophonic line, that would be seriously worrying.

I can't imagine that nobody else ran into that issue, either.

Thanks for taking the time to bounce some ideas back and forth.

Mpc live is ok at this point (OS 2.2.3). jitter was (mostly) fixed in OS 2.2 I believe. I also tried the same test with a Cirklon, which is known for having excellent midi spec and had the same problem.

I am sending the Virus a monophonic line. 16th notes at 120 bpm.

The weird thing is that the Virus has no problem when I use it via USB/TI mode, no timing issues at all regardless of how complex the patch is. So it is not a dsp/power issue. The midi jitter is only when using the midi in jack.

I agree that this isn't the kind of thing that I would be the first to notice, at this point I'm starting to think there is something wrong with my unit. Frustrating as this is the second Virus TI I have bought in the past 6 months that seems to have issues.

Zitat von oliAtBass

This may be a stupid question, but... did you try to send MIDI from your computer to the Virus?

I know that there are quite a lot of users not using the TI but instead sending MIDI to the Virus and recording the analog outputs via audio interface. They'd have run into the same issue.

Maybe I find time to hookup my Darkstar to my MPC Live and try with that setup.

Yes tried midi from the computer as well. This was when I first noticed parts being laggy/sloppy.

At this point it seems really unlikely that it's anything sequencer related, as I have had the same behavior with midi from the computer, the Cirklon, and the Mpc.

Zitat von psylence

If you press config on your virus, there are 3 pages of settings related to midi. There is another one called "audio clock". Please share your settings.

If you can, also use the virus via a midi keyboard and let us know how timing goes. Make sure that the usb cable is disconnected.

IMHO you may need to check the midi settings on your sequencer. Usually when people have timing issues is when the virus is used in the TI fashion so your case is indeed currently odd.

Midi settings are as follows:

Global channel: 01

Soft Thru: off

Midi Device ID: 10

Arp Note Send: off

Midi Clock: sync to external

Midi Volume: Enabled

Program Change: Enabled

Multi Prog Change: Disabled

Audio clock: Auto @ 44.1k

( I have also tried this as internal and at both frequency settings and it makes no difference)

I agree that this case is particularly odd. There really isn't much else I can check on the sequencing side. The Virus is plugged into the same sequencer that I have been using without issue for years. As I mentioned before, I also tried sequencing it from my MPC live and from the computer as well and I get the same sloppy timing (with the Virus) from them all. It's the same setup that I use with an Ob-6, a Blofeld, a Modular, and some other gear and nothing else is sloppy or jittery.

The more I mess around with this I can only really think of 2 different scenarios that make sense.

1. My particular unit has some error or hardware fault in whatever is processing the incoming midi data, and this part is being bypassed when receiving midi data via USB in TI mode. Or -

2. There was a bug introduced in the OS (perhaps in the most recent OS update) that altered the prioritization of incoming midi data (from the DIN port)?

IDK. I can think of reasons why both of those scenarios seem pretty unlikely, but something is not working right and I can't figure out what it is.

Thanks to both of you for taking the time to run through this with me.

Zitat von psylence

Here's another thing to try, probably stupid but...

You are using sequencers in a "loop" fashion right? If the virus has an issue catching up..it never will. So, what if you started your loop say on the 14th bar, i.e. a bit earlier? Does that make a difference?

Yeah, I have tried it in both a "loop" type of sequence and also in a more "song structured" type of sequence and still have the same problem.

Also just gave the "soft reset" a try and that didn't alter anything.

Zitat von psylence

I agree that it appears that the issue is on the virus side and specifically on the midi in side. I also understand that you got this virus used so I wouldnt be surpised if the seller had no idea about this issue, if he was using it only via TI.

Yep, I feel bad needing to contact the seller and inform him that it doesn't work properly, but I'm pretty convinced that there must be something wrong with this particular unit at this point. I was sort of hoping that posting here would reveal some sort of simple "user error" that I was committing, but I can't really think of anything else to try at this point.

Zitat von oliAtBass

Then I started to tweak the AMP Envelope. Added a bit of sustain, added release. And all of a sudden, the timing starts to shuffle. To verify the behaviour, I changed to MULTI Mode put the newly created sound on Part 01, and another Init preset on Part 02. Created another 16th note sequence on the MPC on Track 2 (Midi Channel 02). Started to tweak the second sound, using two Hypersaw oscillators, again with fast filter and amp envelopes, to create a pluck type sound. Interesting was, that both sounds were nicely playing together with no timing issues whatsoever, but whenever I set one of the sounds to long AMP release values, that sound started to "shuffle". Hitting MONO or decreasing Release to 0 cured that immediately. Then I changed to playing the pluck sound with the internal ARP together with a running sequence, and sure enough... timing stayed solid regardless of how ridiculous long the release was set.

You said that timing is good with a simple Init preset, but gets bad with more complex presets. If possible, please share a ROM preset where timing is especially bad. Just to have something that can be verified reliably.

Wow. Interesting. That sounds like the same exact behavior that I am experiencing. I will look for a ROM preset that shows this behavior.

From what I have noticed, the complexity of the preset doesn't seem to matter that much, as long as the voice count (AMP env release) goes up. I can also make the behavior worse by increasing the number of voices in unison.

The fact that you can reproduce it makes me wonder if this was something introduced in an OS somewhat recently and maybe at this point most of the users are just using it in TI mode?

I will post back with a ROM preset that shows the sloppy timing on my machine.

Ok, it was hard to find any ROM patches where this behavior was obvious without a little editing. But here are 2 patches where with a little editing the timing will get noticeably sloppy. (On my machine).

Start with patch ROM B-7 Atx BassMS

(Be careful to only adjust 1 filter at a time)

Adjust filter 2 offset to -40

Set filter 2 to Hipass mode

Adjust Filter 1 Envelope amount to 80%

Adjust Filter 1 cutoff to 0

Adjust filter envelope release to 40

Adjust filter envelope decay to 30

Adjust amplifier envelope release to 100

Rom B-67

adjust amp env release above 80 and it gets sloppy (But not nearly as easy to hear as the first patch).

If anyone else is willing to try this as well, it would be nice to know if this affects all TI's?

Ok, Thanks guys.

Psylence - thanks for posting that, sounds just like mine. So I guess mine is working ok.

I'm kind of surprised that this is an issue. IMO when the voice voice count / processing power is exceeded it should just cutoff the release of the oldest notes (aka voice stealing). I think that keeping tight timing should be the #1 priority. (And it's interesting that this (keeping the timing) is how it behaves when using TI or the arp).

I've used a lot of different synths over the years and this is the first time I can think of one whose timing is dependent on voice count. Pretty disappointed about that TBH.

Anyway, I've sent a message to Access support about it. Seems somewhat doubtful that they would (can?) do anything about it at this point though.