D . A . M . I . A . N .

The Deathlehem Anarchy Machine Intonating Antagonizing Noise - modular synthesizer

This is the new Schematics section - November 0507

Last updated: September 2008

http://deathlehem.com/wsb4569662402/index.html design http://deathlehem.com/wsb4569662402/news.html Links about schematics
Oct. 0508 The 12 position 1V/Oct. semitone switch schematic
This is the schematic for my 12 position 1V/Octave semitone switch that I've designed.

Once you have the circuit together on breadboard, perfboard or a PCB, (including a 0.1uF ceramic capacitor just before the 2k7 resistor - sorry forgot to add that), adjust the multi-turn trimmer whilst measuring the voltage at the buffer's input point to the 100k 1% resistor of your VCO's CV summer.
I change the switch between it's minimum and maximum position #'s 1 and 12 to bring the change in voltage as close to 0.0833V and 1V as possible.
I've used the LM358 as it had been recommended to me as a very low voltage offset opamp - typically between -3 and +3mV.

Tuning seems to be ok, as long as your 12 switch positions give you a voltage that is +/- 1mV from the desired voltage at each switch position.
 1V/Octave 12 position semitone switch
This is also the exact schematic that I am using for each of the 16 switch positions in my Quadatrix Semiblock panel.  (16 of these circuits.)

Any value of resistor may be used for dropping the Voltage Reference's voltage by 1/12th of a volt at every switch position.  I have seen recommendations from others over the years, to use a value between 10k and 100k.  I chose the 30k1 1% resistor (which I manually choose resistors within 0.1% of each other with my digital multimeter) as I have almost 5,000 of them.  :)  There're a lot to choose from to get the exact values to 2 decimal points, for each of the 12 switch positions.  (Over the last few days, I have been matching them into separate containers.  I have dozens of them matched over the range of 30k91 to 30k97.  Each switch has all 12 of them matched EXACTLY to those 2 decimal points.)

Using the LM336Z-2.5V voltage reference, to obtain exactly 1 volt of voltage drop around the 12 position rotary switch, I need ONLY 1 volt coming out of the LM336!
To drop the extra 1.5Vs from it - calculate the TOTAL resistance of your 12 resistors around your rotary switch.

I.E.  If your rotary switch resistors are 20k at 0.1% accuracy then:

12 x 20,000 ohms = 240,000 ohms

You need to drop 1.5 volts from the LM336.  To do this - multiply your 1 volt drop of 240,000 ohms by 1.5 for 360,000 ohms.  Simple. :)

For fine adjustment, I come to a 1.5 volt drop resistor well within 25,000 ohms, as I have a fair number of 25k multiturn trimmers.  I place the 1.5 volt drop resistor, right after the LM336 and the 25k multiturn trimmer right after that one.  From that trimmer, I connect to the first position of the rotary switch.

And there we are kids!  :-)  Enjoy.
Sept. 2008 The 6 position 1V/Oct. switch schematic
I've just completed the successful test of an idea that I had at work last night.  :-)

I had originally bought 25 pieces of the LM329 +6.9V voltage reference, to use for making VCOs with.  An idea last occurred to me, for building a resistor string off of the LM329, to have 6 divisions providing 1V each, for a 1V/Oct. rotary switch, for my VCOs.

Having only 9 x 100k 1% metal film resistors, I chose the 6 from them that were as close to each other as possible - aiming for the 0.1% difference.  (I managed to find 6 of them between 100.2k and 100.5k)

I bread boarded the circuit in the schematic to the right and adjusted the trimmer to get as close to a 1V/Oct. increment at each step, as possible.

The results?? :-)

+6.004
+5.001
+4.000
+3.000
+2.001
+1.003

 Schematic for 1V/Oct. 6 position rotary switch

:-D  I am almost ECSTATIC about these results!

I'll be wrapping all of the components for this circuit around my 6 position rotary switch and mounting it into 1 of my 5 VCOs for testing and let everyone know of the results.  :-)  If it's as successful as I feel it should be I'll then bread board a new test  with 12 0.1%'d resistors to see if I'm able to do the same thing for 12 semitones of increment around a 12 position switch!  :-)  If that is just as successful, I will finally have a cheap and efficient way, to build the 12 position rotary switches for my own sequencer designs!  Here's to hoping! :-D

September 2308 - 12:39 a.m. - with the help from Bluehell at electro-music.com , I added the buffer to the circuit and it NOW works perfectly with the Ray Wilson VCO as well! :)
Nov. 0507 The Liquid Hihat V1.00 Alpha

I've had the idea for a hihat module with voltage controlled frequency, for quite some time.  I have an earlier version of it in my machine, where I did a not very decent modification of the Shimmer section from Ken Stone's Cynare Drum Simulator.  It works, but not as well as I had wished for.

This innovation as you may have heard and / or seen in samples and video, has worked out phenominally well!

I borrowed the Voltage Controlled Clock from a circuit published in Synapse Magazine many a year ago, based around the CD4046 CMOS VCO.

I plugged that in to the EM Magazine / Ken Stone Shimmer section of the Cynare Drum Simulator.  The VCO is a substitute for one of the CD40106 Schmidt Inverter clocks that the Shimmer section itself is normally made up of.  This allows external voltages to be used to control the frequency of the 4046 - allowing the user to have Voltage Control ability over each of the 2 x 4046 VCOs.
The possibilities in sound are beyond imagination!  Please do correct me if I'm wrong, but I do believe this to be the first voltage controllable frequencies analog hihat, in the world.

Errors note:  the only trouble that I have had with the circuit is proper balance between the Liquid Hihat itself and the External Input.  I've done something incorrectly in the final balance area.  
The volume level of the External Input is WAY louder than the Liquid Hihat portion itself.  I've had to put the External Input source through another attenuator to make it's level controllable, outside of this module.
I've made the schematic though, EXACTLY as I've built it myself.  If I don't correct the error myself and post it's correction in the schematic, could someone who knows more theory than I, let me know of it's required correction?  You can reach me at:
damian AT deathlehem DAUGHT com

PCB layout link - HERE
Dec. 0707 The MILLER WD-12 schematic
The Miller Without Drill 1st synthesizer attempt with 2 oscillators was innovated and built by me in 1986, partly from Forrest M. Mimm III's 'Getting Started in Electronics' book, from Radio Shack.


 Miller WD12 schematic
Now please remember - in 1986, I was basically clued out on most everything and hadn't any knowledge about buffer capacitors for power.  I'd added it in this redone schematic, knowing of it's requirement.

This 1st Deathlehem Machine (so renamed, in 1992, when my noise band Deathlehem, was formed) had a few functions to it:
I was able to:
- have all 4 oscillators working independently from each other
- have 2 oscillators working, with the 3rd one modulating the 4th
- have 2 oscillators each modulating the 3 and 4th independently
When 1 oscillator was switched to causing another to turn ON or OFF, adjusting the speed of the modulated one gave a Pulse Width Modulation effect to it, that were rather pleasing to the ear.  Changing the pitch of the modulaTOR of course, changed the pitch itself.

Each of the 4 oscillators were also switchable ON or OFF.

If I were to build a new version of this circuit nowadays, whilst maintaining it's original character, each of it's potential outputs would be properly mixed and buffered so that it worked properly with any external gear to which it were hooked up.

In 1989 I recorded live, directly to tape through 3 multi-fx units, a 30 minute piece that to this day, is still my most favourite Noise piece I've ever recorded:

Wandering Depths / Wondering Minds


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