NEW: 8-Voice Drawbar Organ

Lex Nahumury · Apr 27, 2005, 10:45 PM

K1.3 8-Voice Drawbar Organ (3538)

Despite the availabilty of very good VSTi Drawbar Organs these days,
I couldn't resist spending some time implementing the drawbar principle in DSP microcode.
(What can I say, I'm a sucker for those 'ol' keys.)
http://members.home.nl/nahutec/kxleslie/k13.png

A real Hammond organ has about 80 to 91 tone generators (tonewheels or electronics)
and 9 drawbars to perform it's additive synthese.

To keep DSP resource usage reasonable I settled for;
8 voices polyphony and 4 drawbars.
(4/9*3 = 1.3, hence the name k1.3 )
Each voice uses 4 sine oscilators so we have a total of 8*4=32 sine oscilators.
That plus the additional microcode for gating, VCA, Percussion, Filter, Rotary etc. already
makes it a hefty resource eater.

I have followed Hammond design 'rules' as much as possible;
- Register frequencies (pipelenghts) as hammond
- Foldback on high pitches
- Percussion re-triggers only when all keys released
- High Cut filter on Swell pedal
etc..

How does it sound?
http://members.home.nl/nahutec/kxleslie/kx_drawbars.mp3
Not as a B3 of course. The sines are to 'clean'.
Nevertheless I have fun playing/messing around with it eventhough I own a copy of NI's B4.

Usage:
-Select MIDI-IN Device and Channel as you would do in any other Midi app.
You can NOT use any kX Control Midi Port! (because a kX plugin runs as a thread from kxmixer.exe)
To play directly from your Midi Keyboard, simply select kX UART.
To play from a sequencer, you'll need MIDIYOKE virtual midi driver.
The last Midi Settings are remembered and used the next time you load the plug.

-kX Automation is not used! Instead the Organ uses it's own MIDI implementation.
So far the mapping is;
-Drawbar 1 to 4 = CC12,13,14,15
-Volume = Volume CC07
-Slow/fast = Modulation
-Swell = Expression

-If the Organ recieves Midi data correctly, it's indicator will turn Green
and 'Voices in use' are displayed.
(Use this to check connections)

-Percussion:
The organ uses (steals) the 4th drawbar for percussion.
To get authentic Hammond Percussion set the 4th bar's combo to [2 2/3'] or [4]

Download for 3545;
http://members.home.nl/nahutec/kxleslie/3545/organ.kxl

Update "8-voice Drawbar Organ v1.1b (3538)":
-Fixed a small bug in pitch calculation.
http://members.home.nl/nahutec/kxleslie/organ.kxl

3537 version;
Compiled for 3537 driver version.
(with build-in driver version check)
http://members.home.nl/nahutec/kxleslie/organ_3537.zip

/LeMury

thomasabarnes · Apr 28, 2005, 12:33 AM

LOL LeMury:

This sounds good man!

And that's some mighty fine playing youre doing! Very cool playing, indeed!

Tell me it's you playing and not a MIDI file you got from somewhere?

Daniel Drummond · Apr 28, 2005, 07:32 AM

That's really awesome LeMury! And by the way, where has that "old" rotary speaker effect you were programming gone? Is it the one built in here? Have you tried using one of the fuzz/distortion effects to make it dirtier?

Tiger M · Apr 28, 2005, 07:47 AM

Very nice! You could use parabolas instead of sines for a more "dirty" sound and this will save you quite a lot of registers in expense for instructions. The only bad thing I see is the high resource usage, but I think this is compensated by the great sound.

This is the first completely finished kX instrument! I'm so happy, I knew someday we'd come to this level of development

. Kx gives us so many possibilities.

Lex Nahumury · Apr 28, 2005, 10:58 AM

Quote:

Originally Posted by thomasabarnes

This sounds good man!
Tell me it's you playing and not a MIDI file you got from somewhere?

Thanks. Yep that's me allright.
Jamming along with the drum track I got pretty off beat at times but I decided to leave it this way and not to quantize.
All you here is drum & Organ. Pretty amazing what 'only' 8 voices can do isn't it?
The initial idea was to play the bass line with some Bass guitar,
but before I knew I found myself playing the bass line on the organ.

/LeMury

Lex Nahumury · Apr 28, 2005, 11:06 AM

Quote:

Originally Posted by Daniel Drummond

That's really awesome LeMury! And by the way, where has that "old" rotary speaker effect you were programming gone? Is it the one built in here? Have you tried using one of the fuzz/distortion effects to make it dirtier?

Hey Daniel!
Long time no see. (spending to much time on your emu-card

?)

Yep. The build-in rotary is a somewhat simplified version.
I haven't spend much time on it, so there's room for improvement there.

Yes I have plans to implement some build-in distortion but haven't
experimented yet.

/LeMury

Lex Nahumury · Apr 28, 2005, 11:08 AM

Quote:

Originally Posted by Tiger M

You could use parabolas instead of sines for a more "dirty" sound and this will save you quite a lot of registers in expense for instructions.

Do you have a working microcode implementation of such an oscillator to go along with those statements?
Although I doubt it will improve the sound drasticly, shifting resource usage from GPRs towards Instructions sounds interresting.

Quote:

Originally Posted by Tiger M

The only bad thing I see is the high resource usage, but I think this is compensated by the great sound.

There's no way to realize a 8_voice * 4_Osc synth + build in fx
without using a substantial amount of DSP resources.
Oh what am I talking,..You know that just as well as I do Tiger!

Anyway, .On to something more constructive;
What really may 'beaf up' the sound is feeding each voice's output into a seperate
soft clipper (eventualy followed by lowpass filtering to roll off the highs)

That would mean; 8*clipper microcode.
Since you are the expert here on clipping, do you have any suggestions
on very 'small footprint clipping code'?
Clipping Parameters would be global for all 8 voices.

/LeMury

Tiger M · Apr 28, 2005, 12:17 PM

In your code you use two state registers per sine oscillator. With the following sine approximation you use only one state register, but one more instruction:

Code:

macw counter, counter, frequency, 1
tstneg tmp, counter, counter, 0
interp out, counter, tmp, 0

This is: f(x)=x*(1-abs(x))

It is not a perfect sine, so you have several frequencies above the base and this may probably substitute a 'footprint' soft clipper. Otherwise, you could use the 'log' instruction for soft clipping, but it's not very good in my oppinion, since the curve is not perfect, so we end up with much more frequencies than we want and aliasing could easily step up

As we know we have twice more instructions available than registers, so this ratio in my oppinion should be maintained for all effects.

kokoon · Apr 28, 2005, 01:37 PM

damn man that sounds superSWEET!

nice playing too. the drum track is tight!

will this work on 37?

Lex Nahumury · Apr 28, 2005, 02:28 PM

Quote:

Originally Posted by Tiger M

Code:

macw counter, counter, frequency, 1
tstneg tmp, counter, counter, 0
interp out, counter, tmp, 0

It is not a perfect sine, so you have several frequencies above the base and this may probably substitute a 'footprint' soft clipper.

That's one 'dirty' sine already. This just might do the trick!
I'll implement it to see how it sounds as a whole and report back.

/LeMury

Lex Nahumury · Apr 28, 2005, 02:37 PM

Quote:

Originally Posted by kokoon

damn man that sounds superSWEET!
nice playing too. the drum track is tight!
will this work on 37?

Thanks.
I doubt any 38 kxl will run on <38, but it's no big deal to compile the Organ for 3537 (or older) if people want that.

Come to think of it,.. most musicians probably still use 3537 because of Max's excellent UFX.

/LeMury

Way2Loud · Apr 28, 2005, 03:17 PM

Hello LeMury

Im using an EMU1820 card now, but I kept the 3537 driver on my old computer and I keep returning to this forum just for the reading.
About this B3-clone, I'm totally amazed. You kx-programmers are so much more "creative" (haha) then the EMU-people. Keep up the good work - and I would love to be able to try your drawbar organ with ver 3537.

//W2L

Tiger M · Apr 28, 2005, 04:29 PM

Quote:

Originally Posted by LeMury

That's one 'dirty' sine already. This just might do the trick!
I'll implement it to see how it sounds as a whole and report back.

/LeMury

I've 'invented' it for the synth I'm developing and it is a good sine substitute, moreover it is absolutely stable, you don't have to reinitialize registers each time you change the frequency and the amplitude is constant for every frequency.

Lex Nahumury · Apr 28, 2005, 07:21 PM

Quote:

Originally Posted by Tiger M

I've 'invented' it for the synth I'm developing and it is a good sine substitute, moreover it is absolutely stable, you don't have to reinitialize registers each time you change the frequency and the amplitude is constant for every frequency.

To bad, the harmonics ruin the typical organ sound.
It started to sound more like an Accordion (Harmonica? don't know what it's called in english).
That's a pitty since it is indeed easier to program a stable osc with your algoritme.

Anyway;.. it tells me that the typical 'tonewheel sound' is not a matter of
adding harmonics to the fundamentals. (makes sense since adding harmonics is what the drawbars are for..duh)
The dirty B3 sound is more about picking up all kinds of mechanical noises, rummble, crosstalk etc. etc.
Add to that the overall (tube) distortion from both Leslie as well as B3 pre-amp and voila..!

/LeMury

Tiger M · Apr 28, 2005, 08:38 PM

You could try implementing a global waveshaper, which would saturate just slightly. You could use the same sine approximation formula with a slight modification:

f(in)=in*(1-abs(in)*0.5)

It clips very softly and might add that little 'touch' that you need to make the sound more realistic.

Anyway, it sounds very good the way it is.

Lex Nahumury · Apr 29, 2005, 11:44 AM

Update "8-voice Drawbar Organ v1.1b":
-Fixed a small bug in pitch calculation.

(See download link in first post)

/LeMury

Lex Nahumury · May 4, 2005, 02:28 PM

On user request:

3537 version.

(See first post for download link)

/LeMury

Way2Loud · May 4, 2005, 02:47 PM

Thanks for the 3537-version, LeMury. Now I know what to do this weekend........

//W2L

kokoon · May 5, 2005, 10:20 AM

wow this really sounds great... it sounds really versatile. thanks alot for this 3537 version.

i wouldn't mind some more complete synths built this way...

Lex Nahumury · May 6, 2005, 12:05 AM

Quote:

Originally Posted by kokoon

i wouldn't mind some more complete synths built this way...

I still have an unfinished Bass Synth Project (ala MiniMoog) lying around somewere.
Hmm,..let's see what that brings.

/LeMury

**dj_stick** · May 6, 2005, 12:07 AM

Quote:

Originally Posted by LeMury

I still have an unfinished Bass Synth Project (ala MiniMoog) lying around somewere.
Hmm,..let's see what that brings.

/LeMury

i would find that really useful

Lex Nahumury · May 6, 2005, 02:17 AM

Quote:

Originally Posted by dj_stick

i would find that really useful

2 osc, 24 dB LowPass;
http://members.home.nl/nahutec/kxSyn..._That_Bass.mp3

/LeMury

**dj_stick** · May 6, 2005, 04:55 AM

i'll take a listen when i get home

kokoon · May 6, 2005, 06:42 AM

sir please let us have this

thomasabarnes · May 6, 2005, 08:41 AM

LeMury that's cool man, dude you be jamming!!!!!!

**dj_stick** · May 6, 2005, 09:32 AM

that synth owns

TravelRec. · May 7, 2005, 08:30 AM

I would say: HAMMERGEIL! Unbelievable! And you think ít´s unfinished? It sounds cool for now, not really necessary to finish it in any kind

. I think about a new setup only with synths and organs and so on, seems I can sell my other stuff someday.

Tiger M · May 7, 2005, 02:17 PM

I noticed that the amplitude of the signal is not equal at all pitches it, varies even on two neighbouring keys. This is most probably due to the sine algorithm. I used the same one when I started doing synthesis on the emu dsp and I left it off because of this problem, which deepens when the algorithm is used for FM.

Are you reinitializing the two state registers after frequency change?

Lex Nahumury · May 7, 2005, 02:59 PM

Quote:

Originally Posted by Tiger M

I noticed that the amplitude of the signal is not equal at all pitches it, varies even on two neighbouring keys.

Just checked; Amplitudes are rock stable at -14.4 db for all generators and frequencies.
(You probably didn't 'switch off' the rotary entirely)

/LeMury

Tiger M · May 7, 2005, 03:22 PM

On the higher pitches. It seems that the higher bands dissappear.

http://img.photobucket.com/albums/v4...tinTT/test.jpg

Apr 27, 2005, 10:45 PM	#1
Lex Nahumury DH Senior Member Join Date: Jan 2003 Location: The Netherlands Posts: 1,932 Rep Power: 64	NEW: 8-Voice Drawbar Organ(DSP-Instrument) K1.3 8-Voice Drawbar Organ (3538) Despite the availabilty of very good VSTi Drawbar Organs these days, I couldn't resist spending some time implementing the drawbar principle in DSP microcode. (What can I say, I'm a sucker for those 'ol' keys.) http://members.home.nl/nahutec/kxleslie/k13.png A real Hammond organ has about 80 to 91 tone generators (tonewheels or electronics) and 9 drawbars to perform it's additive synthese. To keep DSP resource usage reasonable I settled for; 8 voices polyphony and 4 drawbars. (4/93 = 1.3, hence the name k1.3 ) Each voice uses 4 sine oscilators so we have a total of 84=32 sine oscilators. That plus the additional microcode for gating, VCA, Percussion, Filter, Rotary etc. already makes it a hefty resource eater. I have followed Hammond design 'rules' as much as possible; - Register frequencies (pipelenghts) as hammond - Foldback on high pitches - Percussion re-triggers only when all keys released - High Cut filter on Swell pedal etc.. How does it sound? http://members.home.nl/nahutec/kxleslie/kx_drawbars.mp3 Not as a B3 of course. The sines are to 'clean'. Nevertheless I have fun playing/messing around with it eventhough I own a copy of NI's B4. Usage: -Select MIDI-IN Device and Channel as you would do in any other Midi app. You can NOT use any kX Control Midi Port! (because a kX plugin runs as a thread from kxmixer.exe) To play directly from your Midi Keyboard, simply select kX UART. To play from a sequencer, you'll need MIDIYOKE virtual midi driver. The last Midi Settings are remembered and used the next time you load the plug. -kX Automation is not used! Instead the Organ uses it's own MIDI implementation. So far the mapping is; -Drawbar 1 to 4 = CC12,13,14,15 -Volume = Volume CC07 -Slow/fast = Modulation -Swell = Expression -If the Organ recieves Midi data correctly, it's indicator will turn Green and 'Voices in use' are displayed. (Use this to check connections) -Percussion: The organ uses (steals) the 4th drawbar for percussion. To get authentic Hammond Percussion set the 4th bar's combo to [2 2/3'] or [4] Download for 3545; http://members.home.nl/nahutec/kxleslie/3545/organ.kxl Update "8-voice Drawbar Organ v1.1b (3538)": -Fixed a small bug in pitch calculation. http://members.home.nl/nahutec/kxleslie/organ.kxl 3537 version; Compiled for 3537 driver version. (with build-in driver version check) http://members.home.nl/nahutec/kxleslie/organ_3537.zip /LeMury Last edited by Lex Nahumury; Aug 19, 2008 at 07:37 AM. Reason: update

Apr 28, 2005, 12:33 AM	#2
thomasabarnes Long Time ***** Friend Join Date: Jan 2003 Location: USA Posts: 1,375 Rep Power: 0 System Specs	LOL LeMury: This sounds good man! And that's some mighty fine playing youre doing! Very cool playing, indeed! Tell me it's you playing and not a MIDI file you got from somewhere? __________________ May a song always touch you in a positive way. SONAR X1D Expanded, Windows 7 Pro 64Bit, MOTU UltraLite MK3, 150 GB HDD, 250 GB HDD, 1 TB x2 HDD 7200 rpm My Music Production: Top 40, Contemporary Christian, Pop/Rock, Decent Rap, Inspirationals, and Children Songs Last edited by thomasabarnes; Apr 28, 2005 at 12:40 AM.

Apr 28, 2005, 07:32 AM	#3
Daniel Drummond DriverHeaven Senior Member Join Date: Dec 2002 Location: Brazil Posts: 1,137 Rep Power: 0	That's really awesome LeMury! And by the way, where has that "old" rotary speaker effect you were programming gone? Is it the one built in here? Have you tried using one of the fuzz/distortion effects to make it dirtier? __________________ www.palcomp3.com.br/ed

Apr 28, 2005, 07:47 AM	#4
Tiger M kX user Join Date: Apr 2004 Posts: 851 Rep Power: 0	Very nice! You could use parabolas instead of sines for a more "dirty" sound and this will save you quite a lot of registers in expense for instructions. The only bad thing I see is the high resource usage, but I think this is compensated by the great sound. This is the first completely finished kX instrument! I'm so happy, I knew someday we'd come to this level of development. Kx gives us so many possibilities. __________________ Miss you, Steve...

Apr 28, 2005, 12:17 PM	#8
Tiger M kX user Join Date: Apr 2004 Posts: 851 Rep Power: 0	In your code you use two state registers per sine oscillator. With the following sine approximation you use only one state register, but one more instruction: Code: macw counter, counter, frequency, 1 tstneg tmp, counter, counter, 0 interp out, counter, tmp, 0 This is: f(x)=x*(1-abs(x)) It is not a perfect sine, so you have several frequencies above the base and this may probably substitute a 'footprint' soft clipper. Otherwise, you could use the 'log' instruction for soft clipping, but it's not very good in my oppinion, since the curve is not perfect, so we end up with much more frequencies than we want and aliasing could easily step up As we know we have twice more instructions available than registers, so this ratio in my oppinion should be maintained for all effects. __________________ Miss you, Steve...

Apr 28, 2005, 01:37 PM	#9
kokoon DriverHeaven Addict Join Date: Feb 2003 Location: slovenia Posts: 269 Rep Power: 0	damn man that sounds superSWEET! nice playing too. the drum track is tight! will this work on 37? __________________ [kokoon]

Apr 28, 2005, 03:17 PM	#12
Way2Loud DriverHeaven Junior Member Join Date: Mar 2004 Posts: 35 Rep Power: 0	Hello LeMury Im using an EMU1820 card now, but I kept the 3537 driver on my old computer and I keep returning to this forum just for the reading. About this B3-clone, I'm totally amazed. You kx-programmers are so much more "creative" (haha) then the EMU-people. Keep up the good work - and I would love to be able to try your drawbar organ with ver 3537. //W2L

Apr 28, 2005, 08:38 PM	#15
Tiger M kX user Join Date: Apr 2004 Posts: 851 Rep Power: 0	You could try implementing a global waveshaper, which would saturate just slightly. You could use the same sine approximation formula with a slight modification: f(in)=in(1-abs(in)0.5) It clips very softly and might add that little 'touch' that you need to make the sound more realistic. Anyway, it sounds very good the way it is. __________________ Miss you, Steve...

Apr 29, 2005, 11:44 AM	Thread Starter #16
Lex Nahumury DH Senior Member Join Date: Jan 2003 Location: The Netherlands Posts: 1,932 Rep Power: 64	Update "8-voice Drawbar Organ v1.1b": -Fixed a small bug in pitch calculation. (See download link in first post) /LeMury

May 4, 2005, 02:28 PM	Thread Starter #17
Lex Nahumury DH Senior Member Join Date: Jan 2003 Location: The Netherlands Posts: 1,932 Rep Power: 64	On user request: 3537 version. (See first post for download link) /LeMury

May 4, 2005, 02:47 PM	#18
Way2Loud DriverHeaven Junior Member Join Date: Mar 2004 Posts: 35 Rep Power: 0	Thanks for the 3537-version, LeMury. Now I know what to do this weekend........ //W2L

May 5, 2005, 10:20 AM	#19
kokoon DriverHeaven Addict Join Date: Feb 2003 Location: slovenia Posts: 269 Rep Power: 0	wow this really sounds great... it sounds really versatile. thanks alot for this 3537 version. i wouldn't mind some more complete synths built this way... __________________ [kokoon]

May 6, 2005, 06:42 AM	#24
kokoon DriverHeaven Addict Join Date: Feb 2003 Location: slovenia Posts: 269 Rep Power: 0	sir please let us have this __________________ [kokoon]

May 6, 2005, 08:41 AM	#25
thomasabarnes Long Time ***** Friend Join Date: Jan 2003 Location: USA Posts: 1,375 Rep Power: 0 System Specs	LeMury that's cool man, dude you be jamming!!!!!! __________________ May a song always touch you in a positive way. SONAR X1D Expanded, Windows 7 Pro 64Bit, MOTU UltraLite MK3, 150 GB HDD, 250 GB HDD, 1 TB x2 HDD 7200 rpm My Music Production: Top 40, Contemporary Christian, Pop/Rock, Decent Rap, Inspirationals, and Children Songs

May 7, 2005, 08:30 AM	#27
TravelRec. Alternative Audioproductions Join Date: Sep 2003 Location: Germany / Sachsen-Anhalt Posts: 1,710 Rep Power: 0	I would say: HAMMERGEIL! Unbelievable! And you think ít´s unfinished? It sounds cool for now, not really necessary to finish it in any kind . I think about a new setup only with synths and organs and so on, seems I can sell my other stuff someday. __________________ Always take a look behind.

May 7, 2005, 02:17 PM	#28
Tiger M kX user Join Date: Apr 2004 Posts: 851 Rep Power: 0	I noticed that the amplitude of the signal is not equal at all pitches it, varies even on two neighbouring keys. This is most probably due to the sine algorithm. I used the same one when I started doing synthesis on the emu dsp and I left it off because of this problem, which deepens when the algorithm is used for FM. Are you reinitializing the two state registers after frequency change? __________________ Miss you, Steve...

May 7, 2005, 03:22 PM	#30
Tiger M kX user Join Date: Apr 2004 Posts: 851 Rep Power: 0	On the higher pitches. It seems that the higher bands dissappear. http://img.photobucket.com/albums/v4...tinTT/test.jpg __________________ Miss you, Steve...