Mustela Modular System up and running
MAX/MSP Build Entry
Week Five – Reflection on Gibilisco Reading
The topics of week five’s three chapters consisted of Impedance and Admittance, RLC and GLC Circuit Analysis, Power and Resonance in Alternating-Current Circuits.
Chapter Fifteen provided a nice introduction to the RX plane and vector representation of impedance. The section on characteristic impedance helpful in thinking about factors affecting transmission lines.
Chapter sixteen was really helpful in circuit analysis and thinking about what I see in a circuit and what it represents mathematically. Often times I see complex impedance in series or admittances in parallel and don’t understand what is happening in the circuit. This has helped me understand the more complex operations happening in a given circuit.
Chapter seventeen dealt mainly with forms of power and resonance. This chapter was interesting, but the least useful to my current work.
I have noticed that some of the chapters are great; however, others are overly broad and make for better “light reading” to pass the time.
Week Five – Envelope Filter Build
Final Build notes on Envelope Filter Pedal
This week was extremely difficult because of some technical difficulties with my envelope filter build. Wiring up the three potentiometers, 9.0 volt battery, AC power jack and input/output jack leads proved to be more trouble than I expected. I purchased solid hook-up wire, which proved to be great for the potentiometers but was a bit stiff for everything else. After a few mistakes, and a lot of sweat, I got everything installed.
I plugged it and saw the LED light turn on, which was a good sign. I plugged in the pedal in the order of bass-pedal amp moving from left to right and couldn’t get a signal going from left to right into my amp. I swapped my cables from right to left in the order of amp-pedal-bass and everything worked great. I had forgotten to reverse the input-output flow in my head after the circuit board was mounted in the chasis.
Week Four – Reflection on Lyons Reading
The Fast Fourier Transform and Finite Impulse Response Filters
The Lyons reading is getting more and more esoteric. I understand the general concepts but the reading is so theoretical, I am still having trouble finding any use to these complex calculations. I suppose if I were a hardware/software designer trying to find the most cost effective method of sampling a signal, this would be really useful. The other part is that I have not had a chance to step back and really look at the reading and think about it.
When one is sampling a signal, using a digital filter limits the bandwidth of the frequency we are recording so we can limit the number of samples needed to obtain a clear representation of the waveform. Otherwise, we are wasting bandwidth and processing power.
It’s interesting that I can imagine using these calculations in the design of cellular phones, VOIP networks and other digital voice networks. I have more trouble seeing how this applies to the hardware and software of digital multi-tracking software. After a recent trolling of Cycling 74’s site, I found some interesting uses of FFT’s. I think it is just going to take some time to really see through the theoretical nature of this book and see the beauty and power of these equations and how they can be powerful tools when it comes to discrete linear-time based processes.
Week Four/Five – Reflection on Gibilisco Reading
This week I decided to jump ahead a bit to delve into the third section of the book dealing with basic electronics. I had scheduled a meeting with Don Johnson who is well versed in electronics and I wanted to mentally prepare myself for our meeting. The three chapters that I read dealt with semiconductors, diodes and power supplies.
I was especially interested in the chapter on power supplies since I was seriously thinking about building my own power supply for my Blacet rack.
I met with Don Johnson on Monday, October 26th of week five. He is an extremely knowledgeable man regarding mathematics and electronics. We discussed logarithmic scales and power supplies. I quickly realized that perhaps the best course of action for now would be to purchase a power supply and wait on a power supply build for the time being.
While poking around in the library recently, I found a book on designing and building power supplies from the TAB electronics serious as well as a handbook on troubleshooting electronics. I think both texts will be of interest in the near future.
Week Four – MAX/MSP Build
This week, my focus was on getting more functionality out of my modular synthesizer build. I completed a front-end mock up my rack and how I wanted various modules to interact with each other.
Next, I started taking some of my individual patches and putting them together into a single modular synthesizer patch. This sounds easy, but each step is a rather time consuming process. I managed to get a rough sine wave oscillator into a filter and out to an amplifier.
I have been reading the online tutorials from Cycling 74’s website and they have been very helpful. I read through a five-part article on a guitar processor build that was really amazing. I’m thinking about doing some reverse engineering to get a slicker front-end look and see how one can chain multiple modules together into a useable network.
The next big step is a 16-step pattern sequencer routable to the oscillator and filter modules. I would also like to be able to send a pulse out to trigger envelope generators as well.
Week Four – Envelope Filter Build
This week went really well with the soldering. I got a chance to look back at my first build and compare the solder joints from the previous week to this week, and saw a lot of improvement. In fact, I’m a bit surprised that the confidence boost even worked.
I started my session by checking the parts against the parts list and testing needed parts with my multi-meter. Checking the colors or resistors is always a bit difficult, even with good lighting so the multi-meter really came in handy. I completed most of the soldering in two sessions.
I am currently looking for a 95 – 99% alcohol solution such as isopropyl alcohol or grain alcohol to clean the flux off of the printed circuit board. I’m using no clean solder, but it is still suggested that one clean the traces and residue on the board.
Next week, I will wire up the pots, switches and hopefully give it a test run.
Week Three – Reflection on Lyons Reading
The Discrete Fourier Transform
From chapters one and two, Lyons launched into hyper warp drive with the discrete Fourier transform. Lyons states in his book that
The DFT enables us to analyze, manipulate, and synthesize signals in ways not possible with continuous (analog) signal processing. (Lyons, 45)
This interests me since I am currently studying analog synthesis techniques and use voltage controlled modular analog systems, which happen to have some limitations. My question concerns how to apply these wonderful processes to create complex signal processing systems.
I am certain that out of this confusion will come some brillian revelations because generally when one tries to comprehend complex sytems too quickly, one does not fully fathom or appreciate their usage.
Week Three – Reflection on Gibilisco Reading
For week three, I jumped into Part II dealing with alternating current basics. The following three chapters dealt with alternating current basics, inductance and capacitance.
The ninth chapter on alternating current basics was interesting in that the chapter mainly dealt with waveforms. This has been the common thread through everything I have been reading.
Chapter ten dealt with inductance. I think this chapter would help in the design of a nice, beefy power supply. Generally inductors are used in analog circuits and signal processing.
The eleventh chapter on capacitance was immediately useful. The Confidence Boost pedal I build used several capacitors in the circuit and this chapter helped explain what they were used for.
Weeks Two, Three, Four – MAX/MSP Multimedia Lab Sessions
For the past two and a half weeks I have been working through the tutorials in MAX/MSP and building simple oscillators and signal processors
During week two, I had set out to create several signal processors since I had been mainly focusing on building oscillators and wanted to try other things as well. My finished builds consisted of a tremolo/ring modulator, a low pass filter.
For the tremolo/ring modulator patch, the source wave consists of a triangle wave and can be modulated with either sub audio modulating frequencies or audio modulating frequencies of various tones. Variables can also be changed within the number box.
The one pole low pass filter uses a sample as the signal source and has an adjustable slider to change the cutoff frequency.
For week three, I spent half of my time developing more complex oscillators and a multi-delay unit. Pictures will be forthcoming.
My current goal is to take these many projects and use them as sub-patches that make up a larger patch. This will consist of an oscillator section, a filter section and envelope section that will be user friendly and highly configurable.
