Wiard Boogie Manual/Patch Ideas

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shady smiles
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Wiard Boogie Manual/Patch Ideas

Post by shady smiles » Thu May 23, 2013 1:06 pm

Greetings!

As per the discussion in the big "meta" malekko manual thread, this is a breakout for Wiard Boogie manual and patch ideas. Discussions not specific to the Boogie might best be held in the meta manual thread (but don't overthink it). I'll update this post with a pointer to an assembled doc once it's in progress, status updates, etc.

Any and all input welcome and greatly appreciated.

Cheers!

-phil

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Post by shady smiles » Tue Jun 18, 2013 6:28 pm

Some raw material from the Wiard 1200 Series Info goldmine. (Content credit to Grant.)
Babaluma wrote: BOOGIE INFO:

The two major variables in filter design are the topology and the transconductor type. A transconductor for synthesizers in simple terms is just a voltage controlled resistor.

The Moog transistor ladder, EMS diode filter and the Boogie filter are all 4 pole Butterworth lowpass filters. Each LP filter "pole" or stage reduces the output by 6 dB per octave. What that techno speak means is each time the frequency doubles, the amplitude is reduced by half. Putting 4 stages in series makes a 24 dB per octave filter, or each time the frequency doubles, the output is reduce to 1/16. The Moog ladder uses transistors as the transconductor, the EMS uses diodes and the Boogie filter uses Vactrols as the transconductor. In theory, there should be no difference in the "sound" of all three. But the ear is such a fantastic discriminator, that it can detect the mathematical defects in each design, so they sound slightly different.

The Boogie (from Boog "Buchla + Moog") uses Vactrols as the transconductor. This should be the closest to mathematically perfect, because the photo resistors are true conductors, not semi-conductors used in a current starved mode to behave as AC resistors. Also the Vactrols optically isolate the control signals from the audio path, eliminating any control voltage bleedthru or thumping.

Another advantage is that resistors are not active noise sources like transistors or diodes, so there is much less "hiss" to deal with. There is always some hiss because electricity does not flow in a perfectly smooth stream but rather in "clumps" of various size groups of electrons. When this "clumpy" current passes through a resistor, it produces a clumpy voltage because of Ohms Law (E = I * R). That is called thermal noise, because the molecular vibrations cause the chaotic electron behavior which we perceive as clumpyness. It is actually a chaotic system of coupled oscillators where each molecule is an oscillator, but that is getting too far out.

Semi-conductors have an added noise source which is the "diode drop" a kind of quantum waterfall, where more clumpyness is added as the electron groups try to decide if they are going to go over the waterfall or not. This is where the noise comes from in a reverse bias transistor. You just hook the transistor up in the worst possible way to bring out the quantum waterfall noise.

So the Boogie is designed to have less noise and distortion than the Moog or EMS implementations of a Butterworth 4 stage filter. This may disappoint people who LIKE noise and distortion. My philosopy is to start with the least possible distortion, then use either over driving or special circuitry to add it back in when you want it.

For the technically inclined, have a look at

http://www.musicsynthesizer.com/Circuit ... %20VCF.htm

The opening block diagram is practically a schematic for the Boogie filter with A,B,C and D being the 6,12,18 and 24 dB per octave outputs. The mixing is done externally by YOU. The resistors shown are actual Vactrol resistors in the Boogie design, instead of a shorthand symbol for the OTA's in a 3372 chip. That eliminates about 100 transistors from the signal path, and should be much quieter. Plus the mixer can be VCA based like the Blacet Quad VCA. So a sequencer or 4 envelopes can be used to mix the filter "poles" for filter mode sequencing or envelope morphing.

Here are some operating notes:

This is an extension of the Lowpass Gate technology using a Butterworth circuit instead of a Sallen-Key. But it is still a gate, and goes all the way off. You can use it like a combo VCF-VCA. The Frequency control range is very wide, from off to 20 kHz. The wide range is to accomodate using the 6 dB/Oct output like a VCA. It will gate either audio or control voltages.

You can use it like a Mini-Moog type filter, in addition to using it like a Lowpass Gate.

With high levels of resonance, the filter will produce distortion at the cutoff frequency. This is useful for processing tracks.

The red jumpers on the back control the phase of the 12 and 24 dB/octave outputs. In the bottom position, the phase is inverted. In the top position, the phase is positive. When mixing the different outputs, the inverted phase allows the Matrix 12 type responses. If you move them to the top position, you can use a JAG and 4 VCAs to make a variable slope filter.

For some background information on using the Boogie Filter for other filter types, see:

http://www.musicsynthesizer.com/Circuit ... %20VCF.htm

which is the section from the service manual on the Oberheim Expander filter. Of course the Boogie Filter uses discrete Vactrols rather than the CEM chip for improved noise and distortion. Cell one is the 6 dB output, cell two is the 12 dB output and so on. Notice the inverters on the 12 and 24 dB outputs, which makes the math "trick" work. You can get some idea of mixing coefficients from the resistor values in the summing networks.

> Sorry if it's obvious, but could someone tell me exactly what a low
> pass gate is, and how I can use my Boogie filter as such?

It's a mode unique to photo-electric filters. Any other transconductor (transistor, diode, OTA) can not run to zero control current without making bad things happen to the DC bias and producing 15 volt thumps. But photo-electric filters go completely off (0 Hz). This allows you to use the filter as a combined VCF and VCA.

In the West Coast model, the complex timbres are generated before the filter via complex oscillators, non-linear waveshapers, FM or additive synthesis. The "gate" is then used for final amplitude and spectral shaping.

The Boogie supports both modes, either straight subtractive with a following VCA, like the East Coast instruments, or gating and spectral shaping without a following VCA, like the West Coast instruments.

The main frequency control covers 20 octaves, 0 to 20 Hz, which is 10 octaves, and 20 Hz to 20 kHz, which is another 10 octaves.

To "gate" with the Boogie, set initial frequency to zero and control range to max. Resonance is set to zero. A 10 volt signal into "Control In" will then sweep the filter from 0 Hz to 20 kHz. The 6 dB output is approx. equivalent to the Buchla 292 "combo" mode, and the 12 dB output is approx. equivalent to the 292 "filter" mode. But the Hamamatsu opto- couplers decay in 20 ms., rather than the 200 ms. decay of the VTL5C3/2 used in the Buchla 292C.

One jumper is for the 24 dB output and the other for the 12 dB output. Move both to top position if your mixing with the Blacet Mixer Processor. Leave both at bottom position if you are mixing with the Blacet Quad VCA.

The effect is high frequency roll off over distance with humidity (adds friction to air). That was the error in the speed of sound measurement variation that Newton never solved. It took 200 years after his death to figure it out (according to PBS). The VCA (or Combo) mode is 6 dB per octave, probably average humidity. 3 dB / Oct would be dry air and 12 dB / Oct would be a visably foggy night (just guessing). Also the 6 dB output of the Boogie can be used for the same effect.

To Summarize: Humidty forms a lowpass filter over distance in air. To simulate this effect in panning, use low pass gates (Borg, Boogie) instead of plain VCAs.

I finally got around to writing an Excel spreadsheet to calculate all the gain settings for the Xpander switchable mixer. (See BoogieModes.jpg) That is what that mess of resistors does before UX14, a CD4051 eight way selector switch. A little later I will write a note to show how to add a simple switch between C1 and ground which will add in the other 8 modes for a total of 16. I unitzed the spreadsheet data to use with the Boogie Filter and any 4 input linear mixer. The file is called Multimode.jpg, you will need to view it at the largest size, or download it.

The table assumes all 4 Boogie outputs are connected to all 4 inputs on a mixer with unity gain output and controls calibrated 0 to 100%. The table also assumes the two red option jumpers on the rear of the Boogie Filter are in the down position. 100% means fader is fully on, 0% means fader is fully off. 50% is fader at halfway point and so forth. There are a few 33% settings and a 17% setting. Feel around the suggested starting points for best results.

All of these are only suggested starting points. ANY setting of the mixer faders will produce some kind of filter. As always with music, adjust by ear and personal taste. You may very well discover a setting Oberheim never even knew existed. Consider running the 24, 18, 12 and 6 dB poles through different effects chains. Unlimited sonic possibilities.

Boogie Filter's 16 Different Modes (Both red jumpers must be in the DOWN position):

Image

Out Of The Box:

1) 4 Pole Low Pass:
24 100%
18 0%
12 0%
06 0%

2) 3 Pole Low Pass:
24 0%
18 100%
12 0%
06 0%

3) 2 Pole Low Pass:
24 0%
18 0%
12 100%
06 0%

4) 1 Pole Low Pass:
24 0%
18 0%
12 0%
06 100%

With External Mixing:

5) 2 Pole Band Pass:
24 0%
18 0%
12 100%
06 100%

6) 2 Pole High Pass + 1 Pole Low Pass:
24 0%
18 0%
12 100%
06 50%

7) 3 Pole High Pass + 1 Pole Low Pass:
24 33%
18 100%
12 100%
06 33%

8) 4 Pole Band Pass:
24 50%
18 100%
12 50%
06 0%

9) 2 Pole Notch + 1 Pole Low Pass:
24 0%
18 100%
12 100%
06 50%

10) 3 Pole All Pass + 1 Pole Low Pass:
24 66%
18 100%
12 50%
06 17%

With External Mixing Plus C1 Switched Out:

11) 1 Pole High Pass:
24 0%
18 0%
12 100%
06 100%

12) 2 Pole High Pass:
24 0%
18 0%
12 100%
06 50%

13) 3 Pole High Pass:
24 33%
18 100%
12 100%
06 33%

14) 2 Pole High Pass + 1 Pole Low Pass:
24 50%
18 100%
12 50%
06 0%

15) 2 Pole Notch:
24 0%
18 100%
12 100%
06 50 %

16) 3 Pole All Pass:
24 66%
18 100%
12 50%
06 17%

...

FILTERS IN MUSICAL TERMS:

It may be helpful to discuss filters in musical terms, rather than engineering terms.

Two 12 dB/Oct filters can always be put in series to make a 24 dB/Oct filter. "Compound" filters like this are essential to really creative synthesis. Another example is a bandpass filter in parallel with a lowpass filter. The reason for this is to make a Formant. Using the lowpass with resonance, and offsetting a parallel band pass with resonance you get a formant. Drive both with a narrow pulse wave and you have a primitive voice synthesizer that can give you vowel like sounds (if the filters are tuned properly). Using a Joystick to control each filter allows you to "speak" different vowels (well, like EEEE and AAAA). If you have two filters try it, it's fun.

A waveform processed by a 12 dB/Oct filter will have stronger harmonic content relative to the fundamental. The tone will be "brighter" in musical terms. These voices are usually used in the treble register as lead voices playing the melody or counterpoint.

A waveform processed by a 24 dB/Oct filter will have weaker harmonic content relative to the fundamental. The tone will be "darker" in musical terms (more muted). These voices are usually used in the bass register for the bass line. The strong presence of the fundimental makes them good for bass lines. You can also take the sine wave output of the VCO and mix it with the filtered tone. This give independent control of the balance between fundamental and harmonics.

The Wiard Boogie Filter provides simultaneous outputs for 6 , 12, 18 and 24 decibels per octave. It's an alternate reality filter which answers the question "What if Don Buchla had designed the filter for the Minimoog?". It is suitable for use in both the bass and treble registers, and as a lowpass gate. Decay time is 20 ms. compared to the 200 ms. decay time of the Buchla 292.

I deliberately designed a series of modules to compliment the Blacet line. In particular, I concentrated on controllers for Blacet modules acting as audio generators. I also added a really phat Moog style filter.

...

FILTER TRICKS:

Running two borgs in parallel produces astonishing stereo images, from natural spacializing to sweet resonant phasing effect when animated...

It's also possible to create some really beautiful and precise harmonic/formant structures when mixing the boogie's and the two borg's outputs in parallel and setting one of them to track the keyboard. (btw my borgs sound a bit different, the last one I received distorts more easily, but with a more crunchy sound, and allows to highlight specific harmonics more precisely, with an even more "woody" sound than the other (!))

I've also been able to find a very convincing cello sound with the boogie as a control source : use the boogie to shape white noise (find the right mix of its four outputs), control its frequency with an eg (I used the very nice bananalogue vcs for this, too sad it's output isn't normalised to the "both" input...), and crank up its resonance. Then patch the mixer's output to the control input of a borg, the vactrols will do the rest ! (adjusting the boogie's parameters allows for a lot of funny effects, like when the borg's vactrols won't be able to track anymore, but there's a sweet spot where the attack is a cello one !) (the other borg is used as tone/body shaper, and the sound source is the sine output of a fixed frequency vco, fm'd and sync'd by a tracking vco/miniwave).

As for the noise ring, it conducts bird singing very convincingly, especially when the miniwave is used as a transfer function device in order to get different probabilities' distribution...But I like it mostly as control source modifier/exciter and tone source (in which case I patch a note-on pulse to the ext change input, to get that ever phased-out sound without clicks)...(It woud be great to have a jumper on its back, allowing to use the clock output as a clock input?)
:guinness:

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Post by shady smiles » Thu Jun 20, 2013 12:35 pm

Power cable orientation and out-of-the-box jumper settings.

The jumpers on the boogie control the phase of the 12dB/Oct and 24dB/Oct audio outputs. In the 1,2 (DOWN) position the outputs are negative; in the 2,3 (UP) they are positive. The boogie ships with the 12dB/Oct and 24dB/Oct outputs at negative phase (jumpers at 1,2 or DOWN -- see picture).

Image

(Edit: updated picture and fixed description.)
Last edited by shady smiles on Fri Jun 21, 2013 7:20 pm, edited 5 times in total.

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Post by sundog » Thu Jun 20, 2013 1:27 pm

shady smiles wrote:Power cable orientation and out-of-the-box jumper settings.
That pic shows the 12dB inverted only. I'd kind of assumed from Grant's instructions that the 'standard ' setting would also have the 24dB inverted. Perhaps I've got it wrong though.

Oh, and thanks for doing all this :tu:

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Post by shady smiles » Thu Jun 20, 2013 3:27 pm

sundog wrote:That pic shows the 12dB inverted only. I'd kind of assumed from Grant's instructions that the 'standard ' setting would also have the 24dB inverted. Perhaps I've got it wrong though.
Nope, I think I'm the one who's got it wrong. That'll learn me for not double-checking before trying to clarify! Of course it leaves open the question what mischief-maker got the jumpers into that state in the first place. Anyway, I'll try and figure it out. In the meantime, the original image has been retracted to be replaced with something closer to the truth. Hopefully later today.
sundog wrote: Oh, and thanks for doing all this :tu:
Cheers! And thanks for keeping me honest. :)

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Post by shady smiles » Thu Jun 20, 2013 7:29 pm

Jumper picture and description updated. Sanity checks welcome! :help:

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Post by sundog » Fri Jun 21, 2013 8:41 am

On my Boogie both jumpers need to be in the 1&2 position (ie down, not up) for phase inverted 12 and 24dB outs :hmm:

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Post by shady smiles » Fri Jun 21, 2013 7:18 pm

sundog wrote:On my Boogie both jumpers need to be in the 1&2 position (ie down, not up) for phase inverted 12 and 24dB outs :hmm:
OK, so you prompted me to check this on a scope and I think you're right!

Image

This shows the boogie jumpered to 1,2 where the 6dB is on CH1 (top) and 12dB is on CH2 (bottom). We have inversion! I updated the picture and text accordingly.

Thanks a million for helping straighten this out. Next round's on me! :guinness:

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Post by Time Machines » Sat Jun 22, 2013 7:56 am

Has anyone modded his Boogie so that this particular capacitor C1 mentioned above is switched out? Or even better, added a switch on the front panel that switches it in or out. I'd love a Boogie modded this way...
FS euro Bananalogue 3P + Doepfer noise

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Post by CarlosS » Mon Jun 24, 2013 2:44 pm

Babaluma did it to his 1200:

viewtopic.php?t=19517

No pics, but these instructions from Grant:
Boogie C1 Mod

There are 9 non-surface mount components.

1 trim pot
4 vactrols
C4 - C1 (L-R)

C1 is located to the far right viewed from the back right next to R7 a 2.2M resister marked (225, 22 and 5 zeros.) Below the power wires and Vactrols and to the right of C2. It may be green or brown but it will be standing up.

The bottom of the cap is ground. De-solder it at the bottom and solder in series a SPDT switch to switch on and off the connection between C1 and ground.

The first issue is drilling hole in face plates, not needed because of switch pots.

Alpha makes a drop in pot with a pulls switch which you can get from Mouser here:

http://www.mouser.com/ProductDetail/Alp ... 5R1-B100K/ ?qs=NdLoOwmN0ORW1MK%2fXhjrjg%3d%3d

Just cut the three wires off the existing pot terminals, resolder to the switch pot then connect your mode wires to the switch in back.
Seems like this is do-able for the euro version - I haven't messed with it yet though. Still searching around for anyone else who has achieved this.

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Post by shady smiles » Mon Jun 24, 2013 6:35 pm

Time Machines wrote:Has anyone modded his Boogie so that this particular capacitor C1 mentioned above is switched out? Or even better, added a switch on the front panel that switches it in or out. I'd love a Boogie modded this way...
I'm hoping to take a crack at this with my boogie (and hopefully Rico by my side for technical if not solely moral support). I'll let you know how it goes if/when I get to it. Of course, if anybody's done it, tips/pitfalls appreciated!

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Post by Time Machines » Tue Jun 25, 2013 6:32 am

Thanks for that link, Carlos, I hadn't seen that thread.

I reckon that using a pull-pot is not really an option with the Malekko version, given how close the pcb sits to the faceplate.

Definitely let us know, Shady, or anyone else brave enough to attempt this mod. I do not fit that last description, though. :hihi: (I have never even touched a soldering iron.) But I'm hoping to find someone kind enough to do this for me. Surely any tips would be useful!
FS euro Bananalogue 3P + Doepfer noise

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Post by shady smiles » Tue Jun 25, 2013 11:05 am

Time Machines wrote:Thanks for that link, Carlos, I hadn't seen that thread.

I reckon that using a pull-pot is not really an option with the Malekko version, given how close the pcb sits to the faceplate.

Definitely let us know, Shady, or anyone else brave enough to attempt this mod. I do not fit that last description, though. :hihi: (I have never even touched a soldering iron.) But I'm hoping to find someone kind enough to do this for me. Surely any tips would be useful!
I'm really hoping to avoid drilling into the faceplate but you may be right about the PCB. I'll have to check it out. Incidentally, there's a great shot of Cat-A-Tonic's borg modded with a switch in the Borg Screaming Res Mod thread. Also there bsmith mentions making a 4hp breakout for these controls which might be a nice alternative to mussing with the faceplates. If nothing else, it's a nice clean way to experiment. Hmmmmm.... Anyway, I'll keep you posted!

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Post by Entrainer » Tue Aug 27, 2013 2:28 pm

Here's one I stumbled across, simple...
Ringmod the 6dB out with the 24dB out. Since the outputs are closely
related, not much happens to the sound except a very nice subtle overdrive/
harmonic quality. I used the X-Mix.
5,159 custom drum samples for electronic music
made from 4 modular systems, drum modules, and some nice analog outboard processing

202 Instruments for Ableton Live/Push (128s), NI Kontakt, and Logic EXS24
41 Kits for NI Maschine, FXPansion Geist, Ableton Drum Racks, and Octatrack Sample Chains
http://www.drivenmachinedrums.com

bertbocklandt

Post by bertbocklandt » Fri Oct 04, 2013 3:47 am

A new boogie filter with those switching options on the front panel would be really nice :party:

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Post by ollepetersson » Wed Nov 06, 2013 12:14 pm

bertbocklandt wrote:A new boogie filter with those switching options on the front panel would be really nice :party:
and a built in mixer! :love:

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Post by hpsounds » Thu Dec 05, 2013 6:09 pm

removed as a protest ... after the SANITARY action :-(

Hédi K.
Last edited by hpsounds on Tue Dec 24, 2013 5:02 pm, edited 4 times in total.

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Post by hpsounds » Thu Dec 05, 2013 6:13 pm

removed as a protest ... after the SANITARY action :-(

Hédi K.
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bertbocklandt

Post by bertbocklandt » Sun Dec 22, 2013 4:06 am

Anybody samples/sounds of the boogie as notch or allpass???

:love:

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