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

[os]

... and expert sleepers' augustus loop in the latter

I recently found and fixed a problem that caused this sort of behaviour (very easily reproducible) in my Minky Starshine plug-in.

it was being caused by filter coefficients being incorrectly clamped, resulting in instability and ultimately infinite values in the audio path - which is what causes total audio drop-outs in the host.

just looking at the Augustus Loop source, there is a similar (but less serious)problem in there, I think. unfortunately it'll probably have to wait till AL v2 for a fix, since the fix might slightly change the character of the filter, which I don't want to inflict on people in a minor update.

os.

[z15]

umm shit,

os,

i actually meant lowcoders' kingdubby, not your augustus loop. i'm ALWAYS confusing the two plugin names - probably because both of them have a famous jamaican dub artist in their name and both are osx only i don't have augustus loop myself... as far as i've toyed with minky starshine demo, it's been working fine so i guess i haven't come across parameter values like that.

it's a good thing to hear about the probable cause of the problem though - i wouldn't be surprised at all if the plugins i mentioned (imposcar and kingdubby) had a similar problems, starting to output infinite values with some certain settings.

[lowcoders]

umm shit,

os,

i actually meant lowcoders' kingdubby, not your augustus loop. i'm ALWAYS confusing the two plugin names - probably because both of them have a famous jamaican dub artist in their name and both are osx only i don't have augustus loop myself... as far as i've toyed with minky starshine demo, it's been working fine so i guess i haven't come across parameter values like that.

it's a good thing to hear about the probable cause of the problem though - i wouldn't be surprised at all if the plugins i mentioned (imposcar and kingdubby) had a similar problems, starting to output infinite values with some certain settings.

Hi,

I'm the one who coded kingdubby. This bug was fixed in an internal release. Depending on the version it was either due to an internal preset getting corrupted (due to legacy code that wasn't updated since the first AudioUnit v2 SDK was released) or to corrupted initial values. Both are now fixed and have been thoroughly tested by myself in Logic 7 pro. My plan was to release a full update along with an improved delay engine, various changes in the filtering strategy and a brand new GUI code (that fully matches the gorgeous bitplant UI elements design) in september or october. In the meantime, there is nothing much I can do. I could seed the internal build but it has no UI and that would not be the full KD experience

[hellleutel]

I‘m afraid if I have to get back to this.
„DC Breakdowns“ still are a constant problem here and occur unpredictably about twice a day. They kill my ears, my monitors, my mixer. Now I know they are not related to a certain Zebra patch but also occur with other, old sound that used to work well.

The precise situation: I use Logic 7.1 buses for internal delays and reverb, and the moment this „dc tilt“ occurs, some of these buses are infected, and a zebra instrument is infected. The buses in question are those to which th Zebra sends.
Infected means: I press stop, I mute the Aux channels that hold the Effects and hear in that moment a pop sound of removed DC. But presssing play still gives ugly DC. Now I mute the Zebra, and finally, the rest is playing well. With the muted Zebra, I unmute the Auxes, and they still are stuck in their DC!!
So I re-load the song, or I reload the Plugins of the Aux channel AND the Zebra and I can continue working.

Now you could say it‘s a problem of logic‘s bus architecture, but there‘s always a Zebra involved. No Kontakt, no Reaktor, no EXS, no ES2, no Atmosphere, whatever. Yes, the problem seems to have started with the update to logic Pro 7.1 or with Tiger, not with a Zebra Update.

My whole system is running very stable apart from that. I find it strange that I seem to be the only one with this problem.
Sorry about my clumsy English, I‘ve no time to refine this....
best u

[Urs]

Hiya,

you're not alone. There's a second case now, fortunately around the corner in Berlin. I'm gonna visit that dude soon and he'll hopefully be able to reproduce it in front of my eyes.

I suspect that it's somehow related to Tiger then. Maybe a subtle change in some of the math/AltiVec libraries I use. I'm still on Panther for compatibility reasons, but maybe it's time to go Tiger now...

I have another idea... will PM you.

Cheers,

Urs

[hellleutel]

Hiya,
I suspect ...
I have another idea...

Thanks Urs, this sounds like some hope. (Too bad that I can not replace Zebra by something in the meantime. Indispensable...)

Greetings to big Berlin
u

[Urs]

Hiya...

... sorry, emailing you didn't work... you got a PM now

Cheers,

Urs