Eagle 1: Description

 by gaussmarkov

To design my circuit boards, I use the freeware version of the Eagle Layout Editor by CadSoft Computer GmbH. The software is located in the download area of their site. On this site, I describe the software and offer component libraries and circuit examples. The libraries are organized for diy pedal circuit design and the examples are popular pedal circuits.

Below is a summary of how I designed a circuit layout with the Eagle Layout Editor. This is part of a series of posts about Eagle that introduce this software in step-by-step detail.

First, I made a schematic of the circuit using libraries containing symbols of the required components. The components snap to a grid that keeps the schematic neat. I drew in the connections and assigned values to the components with my mouse. This is usually the easiest way to record the relationships among the components correctly.

[image: Basic Fuzz Face schematic]

The circuit above is the “Basic Fuzz Face” found in R.G. Keen’s article The Technology of the Fuzz Face on GEOFEX.com, a classic diy pedal article. If you go to GEOFEX, you can find the entire “The Technology of …” series and much, much more.

[image: Basic Fuzz Face ratsnest]

Second, I prepared to layout a circuit board by arranging the physical shapes of the components on another grid. “Rubber bands” (the thin yellow lines) show the connections with nearby components so that you can experiment with where the connections will actually run.

The components and their connections come directly from the schematic, preventing omitted components and mistaken or missed connections. You can toggle between the two layouts, the schematic and the board, making changes in either and they remain consistent.

[image: Basic Fuzz Face layout]

Third, I completed the layout of the board by routing the wires/traces. The software also has an autorouter that will complete the routing mechanically. Typically, placing the components and routing connections is a process with lots of experimentation.

Notice that two of the components, capacitors C1 and C2, have different lead spacing than before. I revised the placement and routing many times to get to this arrangement.

You can use this layout to make the circuit on perfboard or to create a template for etching a circuit board.

[image: Basic Fuzz Face pcb template]

Images can be exported in standard graphical formats at a resolution that you choose. Here is an example of a template for etching a pcb produced from the layout above. All of the gm libraries use a drill size of 0.8 mm (approximately 0.03 inches). To make this image, all of the pad sizes were increased, the components were made invisible, and the image was made monochrome. I chose a 300dpi resolution.

Notes: See eagle: drill size for an explanation of how to change the drill sizes in an Eagle library and see eagle: pad size for an explanation of how to change the pad sizes.

[image: Basic Fuzz Face perfboard layout]

For this perfboard layout image, various colors were changed.


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22 Responses to “Eagle 1: Description”

  1. Ian Ashley said:

    Superb website, very helpful indeed.
    Thank you so much for taking the time and effort.
    Please keep it up!

    Posted 28.01.2008 at 9:43 am

  2. Electronics-Lab.com Blog » Blog Archive » [Tutorial] – Eagle CAD said:

    [...] Eagle 1: Description [...]

    Posted 01.02.2008 at 2:07 am

  3. Marshal Kennedy-Craig said:

    This looks just what I need as an beginner, can’t wait to get a print out and get back home to try this out! Thanks, Marshal

    Posted 14.02.2008 at 5:23 am

  4. krishna_b1in@yahoo.co.in said:

    missing menu items in my cad soft eagle

    Posted 17.04.2008 at 6:03 pm

  5. gaussmarkov said:

    example?

    Posted 17.04.2008 at 7:12 pm

  6. David Aucoin said:

    Hi I am new with electronics so this question may sound simple but I would like to know where the output is on the basic fuzz face diagram you have. I think I know but not really sure. Can you help me with where to attach the input and output jacks and where the swich and led would go.
    Thanks for what you are doing to help people.
    Dave

    Posted 27.05.2008 at 7:41 am

  7. gaussmarkov said:

    You are not alone! This is often confusing to beginners.

    The short answer is to hook the output jack to the middle (no. 2) lug of the LEVEL pot. You can see that the pad for this lug isn’t connected to anything and this is why: because that lug isn’t connected to anything on the board. I just run a wire directly from the lug on the pot to the jack.

    The INPUT is marked on the layout for the input jack wire. So you probably already have that understood.

    As for the rest, I am working on a new tutorial. But you can also go to tonepad.com and look at Francisco’s “offboard wiring” project for several options. generalguitargadgets.com also has this information in every one of their layout diagrams.

    All the best, Paul

    Posted 27.05.2008 at 9:06 am

  8. David Aucoin said:

    You are very kind to help people like myself. I was thinking that migh be the one but wasn’t sure. So your confirmation is greatly appreciated.
    Also thanks for the directions to the other sites.
    Thanks
    David

    Posted 27.05.2008 at 9:23 am

  9. David Aucoin said:

    Also I was wondering if I were to put a 25k or 50k trimmer would I put it between Q2 and gain 3 or between or C2 and gain 2.
    Just thinking it might beef it up a bit becasue the fuzz face I find sounds quite thin.
    Thanks
    David

    Posted 27.05.2008 at 3:30 pm

  10. Allan Hughes said:

    Hi there,
    I’m trying to figure out how to wire this board up (my first project so noobness abounds!) i’ve drawn it out on a jpg and wondered if someone could spot any errors before i start to assemble. Confused about the footswitch and not sure if i have the polarity of the battery power correct is it negative in on this board?
    Here’s a link to the pic
    http://i26.photobucket.com/albums/c143/ringworm_1974/fuzzface.jpg

    Posted 28.07.2008 at 5:23 am

  11. Allan Hughes said:

    Or perhaps this one is better:
    http://i26.photobucket.com/albums/c143/ringworm_1974/fuzzface-1.jpg

    Posted 29.07.2008 at 5:29 am

  12. Bo said:

    Hi, I followed this instruction and built a clone but have 3 problems:
    1. 1. 3DPT switch makes a big pop sound when switched.
    2. Volume comes out from the effect is very very low even at the max level of its pot(500k).
    3. Level (volume) pot makes laud crackling sound when turned either directions.

    Can you understand what went wrong please?
    Regards

    Posted 04.01.2009 at 9:54 am

  13. David said:

    Thank you so much for the easly to follow PNP circuitry!
    However, there is no further instructions to isntall 3DPT, Jacks, LED to this cirtuitry.
    So, at this point I and at a stop.
    Any further instructions or suggestions is greatly apprecitated
    David

    Posted 09.03.2009 at 6:23 am

  14. gaussmarkov said:

    David,

    Please check my article called Wiring up a 1590B and see if that is what you need.

    All the best!

    Posted 09.03.2009 at 11:36 am

  15. David said:

    Paul,
    Many thanks for the link (wiring up 1590B), your in incredible images and top notch instructions are much appreciated!
    David

    Posted 10.03.2009 at 11:44 am

  16. David said:

    Well, trial and errors…
    I followed the PNP circuitry and attached to the 1590B wiring diagram… used 3DPT and a pair of vintage germanium transistors…

    Nothing turned on, no LED, and no sounds…
    Back to the drawing board again :(

    Posted 16.03.2009 at 5:48 am

  17. Ian said:

    Thanks for the wonderful tutorials! The ground pour one was amazing. I’m just wondering how you got the perfboard layout (all black on the white background). Thanks again!

    Posted 14.06.2009 at 4:02 pm

  18. Ian said:

    also, if you don’t mind, how do you add the text to the board that will be etched in the copper. thanks! and sorry for all the questions, i am a noob.

    Posted 14.06.2009 at 4:46 pm

  19. Remco said:

    Hi, could you tell me where to find the specific symbol for the PNP Ge transistors used, with the arrow pointing TOWARDS the emitter on the lower side?

    Posted 19.04.2010 at 4:11 pm

  20. willian_ramos said:

    buenma precentacion en los tutoriales megusto mucho

    Posted 10.06.2010 at 8:50 pm

  21. jpnnt said:

    Hello!
    I realise that noone has posted here for quite some time, but I have a question:
    If I export my layout as a graphic image at 1000 dpi the exported image goes out of scale. How can I get the picture in scale whit the components size so I could etch the layout?

    Posted 12.07.2011 at 4:20 am

  22. agustin said:

    pots are linear, logarithmic and which one is linear or logarithmic

    Posted 08.05.2012 at 11:26 pm



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