Kar+ Strong problem

oddson · 24 Sept 2005

I've hit some odd problems problems with the Joge's Karplus just a while ago, after I attached the standard VCA module lifted out of the example synth. +++ I've opened sambean's fraction Karplus with interface from skOre's mod pack. I assume that's the one you're looking at.

First thing, there's a string with "true" in it attached to the hold on the ADSR. Oddly, it doesn't work (even though not being equal to zero I would assume it's still "true" in the usual programing convention). Replacing with a boolean is making the release work for me. (EDIT - strings are equal to True iff they contain a non-case sensitive spelling of "true". So whatever else was going on here this isn't a factor.)

Also, the gain fader is acting odd... (there's some scaling stuff going on here I don't get on the fader controls).

I'm not having the CPU load problem you are. But I'm having problems getting sound out if I start changing things arround...

(Edit - what' the... restarted SM and sambean's karplus as is works fine including release on the VCA.)

(Edit 2 - definately something odd going on here but can't isolate it. It doesn't seem to be specific to the sustain but is specific to the VCA.)

(Edit 3 - I give up. It's working fine again and I can't replicate either your problem or mine.) 😕

fritzman · 25 Sept 2005

Thanx oddson!

I strangely had similar things. Seldom it worked and most of the time it made problems. Dunno. 😕

Best wishes, FRitz

sambean · 25 Sept 2005

Hi Chaps..

Just had a quick look into and can't seem to recreate any denormal style bugs, but..

I've just noticed the variable delay I used in it is a bit buggy.. Some time after putting this vesrion of Jorge's karplus up, I noticed an error I'd made but forgot to go and update the old links.. 😇

Here's the proper version, also with a few extra delay modules thrown in.. (variable delay, fractional delay- both linear and allpass interpolation) It doesn't have the GUI front pane on though

http://freespace.virgin.net/cc.lai/Frac ... rplus6.osm

I'll let Skore know so he can update the module pack

oddson · 25 Sept 2005

First, nice! I didn't get a chance to really investigate the difference but what I heard sounded really good.

The reason I didn't is that I was playing with the VCA and my problem reoccured.

It doesn't seem to be CPU overload (peaks at about 15% on mine) but I keep losing sound.

It's not the Karplus....

I can replicate it as follows...

Take the simplest chain and insert the stock VCA

midi-in->MtoP->sine->stock-VCA-module->DS-out

turn A, S and R to zero and move D - one note then nothing.

sambean · 25 Sept 2005

Strange.. I just got a similar thing happening.. Switched the release down to zero and then the sound went totally..

fritzman · 25 Sept 2005

Hi folks,

thanx a lot for helping. I found the problem. It's the envelope. I put my env module in and it works. There are "recycling" arrows on the pow modules. That is the sign for synchronized modules, right? This is the only difference I am able to see between my module and the one that Sambeam put in there. Maybe?

Best wishes, FRitz

P.S. resonating delays are fun! 😀

oddson · 25 Sept 2005

I could never wrap my brain around what's going on in that module.

It's the same one the make the gain response so top heavy right?

sambean · 25 Sept 2005

Defo seems like a bug in the ADSR, there's no reason why the sound should totally go like that.. All the inputs seem valid..

It works fine when you swith the ADSR over to the ADSRsr (sample rate)..

It may be something to do with the ADSR recieving small values..

hmmm..

oddson · 25 Sept 2005

One more thing... it doesn't occur unless the hold is set.

I've posted a bug report.

Tom7777 · 25 Sept 2005

I thought that there's some denormal stuff going on in the delay but the envelope has only effect on the amplitude after the KS thingy. Anybody knows what's up? Thanx a lot.

I have also noticed similar things and it also seems that a lot of the older code examples now have denormals also, maybe its something to do with the updates a few versions ago. Some of the old filter examples have denormals in them. Im guessing Sk0re just extracted various things that might seem usefull to users so its possible there is other basic problems in the pack also unless all the modules have been updated.

skOre · 25 Sept 2005

I plan on working not working modules over, but atm have no time and not enought code component experience. Will see to change that in the future, I promise 😉

Tom7777 · 25 Sept 2005

🙂 Same here im still trying to learn DSP code, maybe the devs could make some modules that remove denormals better and then it would be simple to find any problems that might happen in the DSP code, i made a request for this but nothing has happened so far, the basic modules you can find in examples don't seem to fix the problem all the time.