- Audio Club and Arduino Club are on hiatus over the holidays.
- Meetings will begin again at the start of Spring semester. Check here — or on the Discord — in January for new meeting dates and times.
- There may be updates to some of the web-site content during our time away. Look here for any new developments.
- Have a good break, everyone!
A handful of attendees did simple "A-B" tests of several small speakers and a set of amplifiers. G. Tuttle made a couple of simple boxes that allowed for direct comparisons between two sets of speakers or two amplifiers, and we spent the hour switching back and forth between pairs of devices to see if we could hear real differences. We learned that speakers make a huge difference in sound quality. Also with speakers, you can't always judge a book by it's cover. The story was quite different on the amplifier side. We compared a couple of different amps and found no discernable difference. Then we took two identical GTDT amps and started switching the op amps in one of them, trying to detect differences. The prices for the op amps ranged from $0.80 to $8.00. Of course, we expected the more expensive op amps to sound considerably better, but it was very difficult to detect any difference by listening.
It was a fun experiment. The moral from our little exercise: If you have to choose where to spend your money in an audio system, emphasize the speakers.
(Post script for attendees: The little purchased amp that did not work during our tests ended up surviving the ordeal. It started working again when I got it home.)
Upcoming meeting (Arduino Club): Discussion in 3043 Coover at 5:30 p.m. We will go over some "basic skills" for Arduino applications. These include: using the serial monitor, delay and time functions, setting digital outputs, reading digital inputs, and reading analog voltage inputs. If you need to know more about how to put your Arduino (or Cyduino) to use, this is an opportunity to learn a few things.
This was a project building meeting. There were about a dozen club members present. IEEE distributed project kits. Most people were working on building the GTDT amp, but a couple were building Cyduinos.
Here are step-by-step instructions for building the GTDT PCB.
There was a nice turnout for the Audio Club meeting this week. GT gave two presentations The first was a continuation of general amp properties that was started on Oct. 9. The second was an overview of the GTDT amp. This a small desktop amp similar to the Altoids amp but with more output power. The GTDT amp will be the available to build at the Oct. 23 meeting. The presentation slides are linked below.
Editorial note: I've done some re-arranging of files on the web server, trying to add a bit of order to the previous hodge-podge of material. The file paths for some items have changed. Everything should be OK if you access files from the Audio Club and Arduino Club home pages. (But be sure me know if you find any broken links.) However, if you were previously sharing links on discord or by other means, those may now be broken. My apologies for any confusion. –GT
Someone was late to the meeting, so our time this week was abbreviated. We had 30-minute, impromptu discussion about some of the important aspects of audio amplifiers. The discussion will continue next week.
First project-building meeting for the Arduino portion of the club. IEEE provided kits for the Cyduino project. About fifteen people made varying amount of progress on soldering together the kit components. There were a couple discussions about soldering and the design of the project, but most questions were resolved during the build time. More kits have been ordered for those who were not able to get one, and they will be arriving in a couple of weeks.
- Description of Cyduino. (This is a text version of the Cyduino slides present on 9/25, linked below. This document has a bit more detail.)
- Step-by-step instructions for building the Cyduino PCB.
- Instructions on how to load programs onto the Cyduino. (We will probably discuss programming in more detail at a future meeting.)
First Arduino club meeting. There was a nice turnout, and we had a good discussion with many questions from the audience. GT gave two presentations — the slides are linked below:
- General introduction to embedded systems and Arduino.
- Description of Cyduino — a simplified version of Arduino hardware.
First project-building meeting of the semester. IEEE provided kits for the Altoids headphone amp. About a dozen people made varying amount of progress on soldering together the circuits. They did well given that most had little or no soldering experience.
If you missed the meeting, but would still like to build an Altoids amp, contact Ryan Flaskamp to request one.
Information useful for building the Altoids amp:
- The kits provided by IEEE include only the PCB and circuit components. To complete and use the Altoids amp, you will also need: an empty Altoids tin, two 9-V batteries, an audio cable with 1/8-in TRS plugs to connect your phone to the amp, wired headphones with a 1/8-in TRS connector.
- Tools required (in addition the soldering irons in the labs): wire cutters, needle-nosed pliers, a small screw driver, and some way to make the holes in the Altoids tin. (See the step-by-step instructions, linked below, for suggestions about that. Or talk to GT.)
- Step-by-step guide for building the Altoids PCB.
- Soldering tutorial videos: Curious Inventor (6 min), one Tesla (4 min), and EEVblog (34 min).
- A decent 1/8-in audio auxiliary cable. I have several of these cables, and they have worked well for me.
- (Review the basic description of the Altoids amp, linked below,)
First meeting of the semester. There were about 25 people in attendance. Here are pdfs of the presentation slides: