Newbie Question - generic circuit parts

[ChrisG]

Hey all, I've been scouting out the forum recently and trying to gain a better understanding of how to interpret schematics but more specifically, why circuits sound the way they do.

Although building my own effects sounds really fun and a great hobby, I'd like to know more about why, for example, a fuzz circuit sounds like it does. I don't just mean "why does it does it distort?", but rather, "where does the distortion occur in the circuit and why?" / "How can I identify this in a schematic?"

I have tried finding more info on this but haven't found anything that's made much sense to me (being new to all this, that comes as no surprise!).

I've heard of a book of electronics projects for musicians that a lot of people have recommended but I've also heard this is very out of date and a lot of the key components are no longer in production.

Can anyone recommend a good resource for learning about this? I've decided to send myself on an electronics course in the new year as its a subject I'm really interested in, but any help specific to musical projects would be really appreciated!

Thanks very much!

[machineman]

+1 for these questions.  Im also a beginner but I am very passionate about tone and guitar playing.  And I would like to construct my own pedal and know how to modify it.  The problem is I don't know how to change parts that affect tone.  So same thing.  We hope the people here can help us.

[GibsonGM]

Check out the FAQ section in this forum...and the links to AMZ and GeoFX are priceless!  There are articles on the Technology of..(insert FX here, such as wah) at Geo, as well s "What does that part do" or something to that effect.   AMZ talks a lot about boosting and tone controls.   Both of those sites are an invaluable resource for knowledge at a level that will take you from beginner to pro!    Searching this forum for "input cap, output cap, signal path" and the like will also yield some great results.

Look at most effects as different black boxes put together to achieve some desired result.  They are mostly going to consist of a switch for on/off, maybe an input buffer and/or amplification of the very small guitar signal.  Then an operation will be done to the signal (fuzz, OD, distortion...or flange, delay, chorus, etc).  Maybe a tone stack follows that, then something to boost the signal back up since it was "used up" a little in the FX process (a 'recovery stage").   Then you have your output.     In each of those sections, there are areas you can tweak for results...some more effective than others, and learned by reading on here or just experimenting.  Breadboards are priceless )

The best was I could recommend to figure out some tone-changing tweaks is to build a simple FX, like the beginner NPN booster, and mess around with parts values, primarily input and output capacitors.  Listening to the results is very educational )   Then work with clipping circuits, like a Distortion+, and try changing the diodes.   Little by little it will all make sense!  Once you start to identify what the parts are doing, you'll start to know which ones affect the tone of the unit, and which are just "logistical" parts that help opamps/transistors run, etc.    Look into an audio probe, too, to play around and hear what's up inside FX as they operate!  That would tell you much more about how a fuzz works than seeing a schematic.   BTW, that's also covered at Geo ;o)

Hope this gets you a start...   

[ChrisG]

Ahh, that'd great thanks a lot for that!

I'll head over to the Geofex site and have a look at what's on there. I know it'll take some time to build up my knowledge of these things so cheers for the advice!

[Mark Hammer]

You can actually still get Electronic Projects for Musicians as well as another more recent book from Craig Anderton ( http://www.amazon.com/Guitar-Presents-Yourself-Projects-Guitarists/dp/087930359X/ref=pd_bxgy_b_img_b ).  The only things it refers to that are now out of production are specific op-amps.  The functions they perform in those projects are fairly generic and easily replaced; a bit like saying "You can't buy cupboard hinges made of pure brass anymore".  So, while they may be older books, they are still relevant to today.

In addition to the very well-written documents at www.geofex.com and www.muzique.com, I will also recommend the scanned copies of (now defunct) newsletter "Stompboxology", available at Charlie Barth's site: http://moosapotamus.net/IDEAS/stompboxology/stompboxology.html  and the scanned copies of Anderton's old newsletter DEVICE available at my own site: htt://hammer.ampage.org (site page 10 and 11).  Although the Stompboxology issues may seem to be about topics you might not be interested in at the moment, the author does a nice job of explaining what each portion of the circuit does and provides numerous examples.

All of these resources, plus the many articulate postings accumulated here over the years, do an excellent job of teaching absolute beginners what is going on in circuits, and what does what.

Please note that it WILL take you a while to get up to speed.  Be patient.  This is no different than learning another language. You would not expect to be perfectly fluent in any language different from you first tongue in less than two years, and I think the same expectations apply here.  Like any second language, however, you WILL be able to horse around and make small "chit-chat" in little snippets after 4-6 months or so.

[bipedal]

At this point, I've built half a dozen pedals and modded several others, and still consider myself pretty much a newb in the theory side of things.  That said, I know a LOT more than when I started!  Here's what I've found most helpful in my ongoing quest for ultimate guitar tone via DIY:

1)  Even if you don't build them, make sure to read step-by-step through the three "beginner" projects that can be found on this forum's home page.  Good tutorials for 'we use this part to accomplish _____' and for building best practices.

I didn't take a close look at these tutorials until after I had already successfully built a few pedals.  I found I was getting to know the parts and was starting to see some patterns in the different circuits, but wasn't really making progress on the theory behind the circuits' operation.  Those project tutorials were very helpful for me in building my understanding of the why/how questions.

2)  Spend some time reading the "Technology of the Fuzz Face" and "Technology of the Tube Screamer" articles (easy to find online) -- so much great fundamental info in those two pieces about circuit components and how they interact.  If they don't make sense upon first or second read, file 'em away, go build yourself a pedal based on one of the many great designs available in the gallery or elsewhere, then come back and re-read the articles.  I found that I get a bit more out of those articles every time I read them.

3)  Lurk on the forum.  Tons of great ideas and info to be found -- even if it's a discussion about a pedal you don't know or have no intention of building, you'll likely find a lot of the ideas are transferable to other projects.

Enjoy -

- Jay