u-he

hellleutel · Post by **hellleutel** » Wed Jul 20, 2005 4:47 pm

hi.

today I spent some time programming Zebra sounds, when all of a sudden, with an ugly "DC offset full scale" type click, the whole audio engine seemed to have stopped. It's Logic 7.1, Macos 10.4.2.
I turned down the volume as fast as I could, removed the Zebra plugin and here we go: everything else sounded well again. EXS, Reaktor, even the other two Zebras.

After this had occurred twice, I decided to stop this programming session...
http://www.uli-reuter.de/OtherFiles/Zeb ... 0.aupreset this is the sound I was working on so far (have to use modwheel)

Urs do you have an idea? the other two zebras in my song have been working well (with older sounds) Did I build something to make it collapse somehow?

The same problem used to appear from time to time with a certain other plug last year - which I therefore decided to put aside for a while.

Best

Ulrich

Urs · Post by **Urs** » Wed Jul 20, 2005 11:42 pm

Hmmm, this might happen... what did you do to the poor Zebra? I'll have a look tomorrow...

Cheers,

Urs

Citytea · Post by **Citytea** » Sun Jul 24, 2005 9:08 pm

Urs wrote:...what did you do to the poor Zebra?...

Hellleutel. Confess. You drew and quartered it, didn´t you?

In fact this could happen already before the Tiger and Logic 7.1. Had a talk about with Urs - but still no idea about the reasons...

Urs · Post by **Urs** » Sun Jul 24, 2005 11:30 pm

It's actually easy to do this... feed a sync'd osc (Sync = DC offset) into a comb filter with double feedback... bang...

Sorry, I forgot to check out the preset. Will hopefully remember to do so tomorrow...

Cheers,

Urs

hellleutel · Post by **hellleutel** » Mon Jul 25, 2005 7:06 am

Urs wrote:Sorry, I forgot to check out the preset. Will hopefully remember to do so tomorrow...

I was already starting to get nervous.

BTW i think I had the same "tilt" effect once when feeding too much back into a feedbackloop in reaktor.

but sync is off in my patch, and feedback isn't involved either.

relaxedundoeko · Post by **relaxedundoeko** » Mon Jul 25, 2005 8:47 pm

Shouldn't the audio interface have an output capacitor cancelling all DC? I would think that the ugly click you hear is just the transient of the DC signal switched on passing through that highpass.
In this case, would we need to fear any damage of our speakers?

hellleutel · Post by **hellleutel** » Thu Jul 28, 2005 1:18 pm

relaxedundoeko wrote:Shouldn't the audio interface have an output capacitor cancelling all DC?

Hi it's not jus a click, its a heavy click + mute of all audio + no instrument reacting until I disable the Zebra. I also don't see much in my patch that could produce big DC

Has anyone tried my patch?

If I have to be afraid of freakdowns like this, I don't really feel like Zebra programming anymore.

Or might it be a Tiger (10.4.2) issue?

Urs · Post by **Urs** » Thu Jul 28, 2005 1:36 pm

Hiya,

I couldn't reproduce any click of death with the patch, but if at all, I'd assume it happens in the Comb/Delay at bottom of the first channel in the Grid.

Another chance would be the combination of filters, i.e. if the HighSelf and the Peaking create a large emphasize at a frequency that's also a formant in the two Formant filters, I could assume that the values quickly build up to some sort of "point of no return". I've never seen this happen though...

What samplerate are you using?

Cheers,

Urs

hellleutel · Post by **hellleutel** » Thu Jul 28, 2005 8:18 pm

Hello, I'm using 44.1; I must say that my song was in fact very "big"... Many EXS, Ivory, Uad and other plugins, even Reaktor instances.
" I've never seen this happen though... " - so as this is a very simple patch, the problem must come from elsewhere. Maybe Tiger 10.4.2 ?

Anyway now I tested the patch it in an empty song, removed the delay, 10 minutes without problems, but then a crash (!) when I tried to save a spectrum. Grr. I'll do something different from now

Urs · Post by **Urs** » Thu Jul 28, 2005 11:41 pm

hellleutel wrote:crash (!)

Eeeek! Can you send me the crash.log to urs at u-he dot com?

Might be something weird with Tiger... gotta check this out...

Cheers,

Urs

Citytea · Post by **Citytea** » Fri Jul 29, 2005 7:02 am

I tend to think, there is not a genuine problem of Zebra nor Tiger - it seems to be more a problem of Logic, I´m assuming meanwhile. Am I right, this one is the hosting Software, every time, this problem comes up? I also remember having this prob with another plug but at logic one time meanwhile!

There is a very interesting thread at the german Logicuser Forum (which most of the persons involved at this thread should be able to follow in its origin language as well...) where a problem of EQing is to be discussed, it seems to come to unexpected line-level-raisings at Logic, if the EQs are set to a lower bass-level f.e. Thread to be found here:
http://www.logicuser.de/forum/viewtopic ... 482#150482

Maybe some filter-settings (of zebra as well as at other third-party plugs, lets say the waves EQ) may affect the line-level of logic in a way that leads to those clipping effects! (Although there is this full-load of the zebra-level-meters, when clipping... does zebra use the hosts internal sample-rate, when being used as plug-in, Urs?)

Maybe this is related to the internal sample-rate-change to 32 Bit while processing, Logic does - what seems to be done in genuine exactly to prevent from clipping and allowing this generous range of +6db at the levels, before it should start to clip at all. In fact you can watch, that there might be heavy clippings even under the level of 0db in some plug-configurations, where there are other situations, you can wham the levels to top at both, the instrument and the output, without any distorting noise... I think, the reasons for our problem are hidden in the secrets of Logics gain processes - but - a lots of maybes. Maybe it is helpful to the wizzard of plugs anyway!

And - to open another aspect of a former discussion: Couldn´t this also be the reason, why final Cubase songs sounds so much better, as the ones of Logic? (Lungfull, can you hear me??)

Urs · Post by **Urs** » Fri Jul 29, 2005 8:57 am

Citytea wrote:does zebra use the hosts internal sample-rate, when being used as plug-in, Urs?

Yes, except for the reverb which always runs at 44.1/48 kHz.

That's an interesting phenomenon... I'll keep watching that thread on Logicuser...

Cheers,

Urs

z15 · Post by **z15** » Fri Jul 29, 2005 9:17 am

ooh.

i've had the exact same thing happen with gforce imposcar in both live5.0.1 and logic6... and expert sleepers' augustus loop in the latter, haven't tried it with live yet. i can't quite pin down how to reproduce the problem - with live it was enough to have one imposcar running the default preset, open another imposcar and play a single note. it didn't cause the problem every single time but sometimes it did - i got a pop and the whole audio engine fell silent. bypassed / removed another imposcar and it was gone.

haven't been able to get zebra to act like this but it seems that it's a problem with more than one au / vsti then... still, weird - i mailed dave at gforce about the problem and they said they'd never run into a problem like that before and promised to look into it.

ps. hi urs

Urs · Post by **Urs** » Fri Jul 29, 2005 9:49 am

Vae!!!

Didn't know it was you!!! How's it going?

Cheers,

Urs

z15 · Post by **z15** » Sat Jul 30, 2005 8:25 am

sehr gut, having holidays and trying to finally get some songs finished after falling in love with ableton live

how's beautiful and sunny (i hope!) germany?

u-he

KVR Audio

Zebra (with Tiger) occasional total audio dropout!?!