Download Dabay_Polyphonic-Analog-Syntesizer_hw2

Thomas Dabay
Analog Polyphonic Synthesizer
Technical Description: This project will consist in designing and fabricating a mostly analog polyphonic
synthesizer. The basic building blocks of the synthesizer will be oscillation circuits (ex: Voltage
Controlled Oscillators for note production and Low Frequency Oscillators for modulation and filtering),
filter circuits (ex: basic High/Low/Band Pass filters for tone shaping and Voltage Controlled Filters for
dynamically changing filtering), modulation circuits (ex: Tremolo and Vibrato circuits to create the
respective effects), and amplifier circuits (ex: Voltage Controlled Amplifiers controlled by envelope
generators for creating note dynamics). Also, it will hopefully have a digital signal processing stage to
facilitate a multi-effects processor with more complicated effects, such as reverb, delay, compression,
and amplifier modeling, and possibly some sort of memory to store sound patches. Both of these will
necessitate the use of A/D and D/A converters.
Potential Impact: Although the market for synthesizers is fairly crowded, most manufacturers focus
primarily on digital products. Also, there appears to be a renewed interest by consumers in analog
synthesizers. These two facts add up to an analog synthesizer being a viable product for a new company
to produce, especially if it is both affordable and functional.
Sales Description: The synthesizer will more than likely be designed as an affordable, entry level
synthesizer to better compete in the crowded market, although with certain higher quality features.
Also, the possibility of releasing it as an unassembled kit will be considered, as it will appeal to the do-ityourself market as well as keep both per-unit costs and company start up costs low.
Initial Evaluation: This project appears to be practical in both the sense of cost and time to complete. In
the sense of cost, there should be few really expensive components/parts necessary for the design
because the analog technology involved has been around for so long. In the sense of time to complete,
this project will be very flexible. Although there are certain basic design elements that need to be
included for it to be a functioning synthesizer (e.g. oscillators, filters, amplifiers, a keyboard), these
should not come close to taking up the entirety of the project time. This will allow time for
development of other, optional design elements such as effects, more complex filters, etc. Basically,
the necessary design elements should be able to be design relatively quickly, and the rest of the time
can be spent expanding on the “optional” features.
Simplicity Evaluation: In my opinion, this project should not be too simple for a two semester, multistudent senior design project. I believe this primarily because of the flexibility mentioned in the “Initial
Evaluation” section. Again, the basic design elements will more than likely be very simple, with the
biggest problem really only being circuit optimization, but the optional features can be as complicated
as the group wants them to be.
Additional Skills: Due to the nature of this project, an understanding of or interest in analog electronics
will be important for most group members to have. However, I am planning on implementing at least a
couple digital circuits (A/D and D/A converters that will facilitate a multi-effects processor) so group
members with a solid background in both digital circuits and programming would be beneficial.
Components Needed: Right now, very few specialized components should be needed for this project.
Most of the analog circuits will require little more than basic analog components, such as resistors,
capacitors, transistors, op-amps, etc. At this stage, the multi-effects processor and the keyboard are the
only really specialized components that would be needed. However, more specialized components will
probably be needed for the optional features but the group needs to come to a consensus on what
features to add.
SWOT:
Strengths – One of the key strengths of this project is the flexibility that has been mentioned earlier in
this paper. This flexibility has many benefits, some of which have been mentioned already, but most
importantly it will allow group members to gain a broad overview of analog signal processing, as well as
digital signal processing for those involved in the multi-effects processor. As a marketable product, this
project will be entering an established market, which has its advantages and disadvantages. For this
section, this is advantageous because the market is known to be viable, and although there are major
brands to compete with, there is still room for smaller companies if they have a new, novel, or superior
product or are looking to fill a niche.
Weaknesses – This project has a couple noticeable weaknesses. This first is that the basic design
elements are relatively simple, although the optional features should increase the complexity to an
adequate level. Also, this technology is very old and probably will not appeal to those looking to work
with cutting edge technology. Also, the market it would be entering, since it is already established, is
fairly crowded compared to the markets of more cutting edge technologies. As such, any new product
would have to differentiate itself from the others to be viable.
Opportunities – The most obvious modification that could be made to this project is to make a digital
synthesizer instead of an analog one. The resulting project would focus considerably more on the digital
signal processing aspect and could facilitate numerous different synthesis techniques (such as Frequency
Modulation, Analog Modeling, Wavetable).
Threats – As a learning opportunity, the only real threat of failure in this project would be group
indifference (e.g. only caring about the basic design elements and not the optional features). As a
marketable product, the biggest threat would be if the group were unable to differentiate it from
existing products.