KVR Audio

Frippertronix · Post by **Frippertronix** » Wed Apr 18, 2007 11:00 pm

Sorry I mised the detune---honestly I do have a bit of a hard time reading this GUI, too, but I'm learning.

Chris Walton · Post by **Chris Walton** » Thu Apr 19, 2007 1:31 am

AdmiralQuality wrote:Really guys, if you're taking the LFOs up to sonic you're into some uncharted far-out territory there. I just let them go that high because I believe the controls should "go to 11", wherever possible. If you don't like it, just don't do it! A square wave at 100 Hz modulating the filter at near maximum depth will take the filter from wide open to completely shut, it really is just a ring mod at that point. Some of you seem to have the idea that no setting should be capable of making a bad sound, but that's just not how it works.

The oscillators make much better audio rate modulators. And they can be tuned to the keyboard so they'll produce meaningful pitches instead of the static LFO rate.

Chris, want to smooth an LFO? Run it through a Mod mixer and turn the Lag (just a 1 pole LPF) up a bit.

Note that in Poly there's not just two global LFOs shared by all voices as in most classic designs. In Poly each voice needs it's own 2 LFOs so that the LFOs can be set to retrigger. Trust me, you'd see a big performance hit if I did something more them.

You aren't getting the point - its simply wrong and introduces aliasing. The reason you don't notice is because (1) you hear the synth everyday (2) you have everything run at 8x followed by a huge filter to downsample it. Try any other decent synth and do a square wave modulation of the filter. Or try an analog. Hear any clicks? I don't, but I do in Poly-Ana. And I see them in my frequency analyzer and my oscilloscope.

Smoothing with an LPF will get you there a bit but not all the way. What you'd want is a bandlimited, ripplefree square (yes, that is possible), oversample the whole thing twice, and PRESTO - alias free square wave LFO.

Easiest way to do it would be BLEP, with an appropriate FIR (for modulation, that means NOT windowed sinc). I don't know how your normal oscillators do their thing but BLEP is trivial to do and can get you imperceivable amounts of alias without any oversampling. I know this because I've done it.

And yes, I am saying that 8x oversampling everything is overkill. Good oscillators dont need any oversampling, the modulation stuff suffices with 2x modulation. I assume your filter is a ladder filter so that needs 2x oversampling as well, and since you're audio-rate modulating the filter, 4x. Its usually a good idea to process everything at the same samplerate then downsample at the end, so 4x throughout. Thats half the CPU power needed right there. I'm sure a few extra BLEP oscillators wont increase CPU by more than half.

And an addendum .... I noticed some DC Offset. Are you using minBLEP and forgetting to adjust for phase delay, by any chance?

AdmiralQuality · Post by **AdmiralQuality** » Thu Apr 19, 2007 2:19 am

Looks like I'm going to have to tear it all up, go back to version 0.0, and start coding again from scratch to accomodate the building of your Rube Goldberg synth Chris. Oops, I mean boss.

VitaminD · Post by **VitaminD** » Thu Apr 19, 2007 2:44 am

wow...

Stupid American Pig · Post by **Stupid American Pig** » Thu Apr 19, 2007 3:27 am

heh welcome to arkeland AQ!

LBN · Post by **LBN** » Thu Apr 19, 2007 3:49 am

A Rube Goldberg synth would be really sweet.

AdmiralQuality · Post by **AdmiralQuality** » Thu Apr 19, 2007 3:59 am

LBN wrote:A Rube Goldberg synth would be really sweet.

I know eh? I thought the same thing shortly after I wrote it.

Anyway guys, I don't mind suggestions, and by all means ask for features you'd like to see added. But THIS is the product. Like it, or don't. That's all fine. But I can't change it fundamentally or all those paying customers who sent me mail raving about Poly's sound will turn on me, and rightly so! And speculating wildly on proprietary stuff I obviously can't discuss (I'm not even allowed to say how wrong it is) and telling me what to do, when you clearly don't understand what I've done already, probably isn't the best way to convince me of anything.

'Nuff said. Back to fun synthy stuff now, k?

Chris Walton · Post by **Chris Walton** » Thu Apr 19, 2007 5:59 am

AdmiralQuality wrote:Looks like I'm going to have to tear it all up, go back to version 0.0, and start coding again from scratch to accomodate the building of your Rube Goldberg synth Chris. Oops, I mean boss.

Nothing I said would change the sound fundamentally or anything. I suggested a fix for getting rid of some aliasing with LFOs. I noticed you were hanging around BLEP threads a while back so I assumed its likely that your slight DC Offset could come from a minBLEP without phase delay adjustment (very common, most people dont bother to fix it the "right" way and instead add a highpass filter). Finally, I suggested that unless theres something going on back there you're not telling us (your latest post makes it seem like there is) that 8x Oversampling the whole thing is quite alot. My wording the second time around might have not been the greatest (it was 3am for me) but you're the one that started getting pissy about the whole issue.

AdmiralQuality wrote:And speculating wildly on proprietary stuff I obviously can't discuss (I'm not even allowed to say how wrong it is)

Did you have yourself sign an NDA?

Urs · Post by **Urs** » Thu Apr 19, 2007 9:12 am

Chris Walton wrote:a bandlimited, ripplefree square (yes, that is possible)

No it isn't. It may look like a square wave but it's got a different spectrum.

Any sampled square wave has "jaggy edges".

Chris Walton wrote:square wave modulation of the filter. Or try an analog. Hear any clicks?

Yes, my Moog "clicks" nicely.

It's a myth to think that analog is oh-so-perfect.

camsr · Post by **camsr** » Thu Apr 19, 2007 9:25 am

arke you should be more respectful of AQs creation here. He took alot of time to make it and personally I think it's one of the best ideas for a VST we've seen in along time. My only concern is the readibility of the GUI but that's my own issue, because I like big easy controls. I would love to hook Polyana up to a hardware control surface, which would make it alot easier to tweak.

Kingston · Post by **Kingston** » Thu Apr 19, 2007 9:33 am

Stupid American Pig wrote:heh welcome to arkeland AQ!

suddenly I remember why the prick was banned so many times already. he's out of his depth. again.

AdmiralQuality · Post by **AdmiralQuality** » Thu Apr 19, 2007 1:32 pm

Kingston wrote:
Stupid American Pig wrote:heh welcome to arkeland AQ!
suddenly I remember why the prick was banned so many times already. he's out of his depth. again.

Frippertronix · Post by **Frippertronix** » Fri Apr 20, 2007 4:31 am

On a lighter note, I realized why I missed the detune knob before: at 1024 by 768 it's almost completely blocked by the Win XP taskbar.

AdmiralQuality · Post by **AdmiralQuality** » Fri Apr 20, 2007 4:46 am

Frippertronix wrote:On a lighter note, I realized why I missed the detune knob before: at 1024 by 768 it's almost completely blocked by the Win XP taskbar.

Going to look into adding a keyboard-only view. (Running out of space to put a button to toggle it though!)

Until then you can set your Windows toolbar to not be "Always on Top", that'll give you a few more pixels. That's the way I always run it.

What host do you use Frip?

zerocrossing · Post by **zerocrossing** » Sat Apr 21, 2007 3:23 am

Well... your synth sounds mighty nice Mr. AdmiralQuality... Mighty good. However, it's one of the only VSTi plug ins I've ever used with Live 6.0.5 that froze and then brought down Live. I wasn't even doing anything bizarro... just running through presets.

I know there's a lot of talk about the GUI... while it's fine I can't help but think those rendered knobs are taking up an awful lot of pixel real estate. Expecially the mod routing selectors. Woah nelly.

People may jump down my throat, but this sure isn't an analog synth. It's software. While it's nice to take what's great from the past, also remember that it's 2007. I'd apprecate this GUI if it were just a UI. Make a clickable drop down menu that lets you select your source and be done with it. Urs' stuff uses this. Now that man can make a synth and an interface.

All that said, I'm very interested in seeing what a stable version of Poly-anna can do. Seems like it's going to be a great VA.

Mark

Poly-Ana 1.0 New VA softsynth. 1 week full functioning demo