Good DIY Pedal Build to Learn About Op Amps?

[tlite]

OK. I admit it. I don't really understand op amps. Are there any good DIY pedal builds that would give me some hands-on experience working with these things?

I've built a few pedals already (none with op amps)- not an expert, but not a total noob.

Thanks!

 

[RobbieK]

How about a tube screamer. I know it's not really a bass pedal, but there's a lot written about how it works. Here's one nice article from the well respected RG Keen. Wampler also makes YT vids that go into detail explaining tube screamers etc. Just in the first opamp, you'll get a pot in the feedback loop for gain adjustment, a HPF with the virtual earth cap, a LPF with the little feedback cap, and clipping diodes thrown in as well! Then in the 2nd opamp, you get the basic anatomy of graphic EQs, with the RC filter swept from inverting to non-inverting inputs. Also there are lots of stripboard layouts etc, and also info on modding.

Or how about a graphic EQ? A typical one will give you an opamp buffer, plus a row of opamp gyrators to get your head around...​

 

[tlite]

How about a tube screamer. I know it's not really a bass pedal, but there's a lot written about how it works. Here's one nice article from the well respected RG Keen. Wampler also makes YT vids that go into detail explaining tube screamers etc. Just in the first opamp, you'll get a pot in the feedback loop for gain adjustment, a HPF with the virtual earth cap, a LPF with the little feedback cap, and clipping diodes thrown in as well! Then in the 2nd opamp, you get the basic anatomy of graphic EQs, with the RC filter swept from inverting to non-inverting inputs. Also there are lots of stripboard layouts etc, and also info on modding.

Or how about a graphic EQ? A typical one will give you an opamp buffer, plus a row of opamp gyrators to get your head around...​

Thanks- very helpful answer and links. I never even considered an EQ, but I really like that idea as I could use one. I like the TS idea as well- though kind of excited to build something other than a dirt pedal. I may build 'em both!

 

[byacey]

Look for a book entitled "IC Op Amp Cookbook" by W. Jung. It has theory and practical design information.

 

[tlite]

Look for a book entitled "IC Op Amp Cookbook" by W. Jung. It has theory and practical design information.

Thanks! Just ordered a copy.

 

[byacey]

Another good reference by the same author is "Audio IC Op Amp Applications".

 

[Passinwind]

For an excellent overview on building with opamps, and even a complete bass preamp design: Link Removed

 

[byacey]

For an excellent overview on building with opamps, and even a complete bass preamp design: Link Removed

I forgot about that; another excellent resource.

 

[delta7fred]

For an excellent overview on building with opamps, and even a complete bass preamp design: Link Removed

One of my favourite sites, so much good stuff.

 

[Matt Liebenau]

If you can find Craig Anderton's books "Electronic Projects for Guitarists" and "Electronic Projcts for Musicians", if I'm remembering correctly, they have a lot of good projects, many opamp based. They're a little old but good tone is timeless.

 

[tlite]

Thanks!

For an excellent overview on building with opamps, and even a complete bass preamp design: Link Removed

Thanks very much! This is quite a rabbit hole I seem to be going down... hopefully this stuff isn't too over my head. Nonetheless, that's how I learn stuff- by taking on projects I am absolutely not qualified to do. But eventually I get there... usually.

 

[Passinwind]

Thanks very much! This is quite a rabbit hole I seem to be going down... hopefully this stuff isn't too over my head. Nonetheless, that's how I learn stuff- by taking on projects I am absolutely not qualified to do. But eventually I get there... usually.

You might consider building up my open source onboard preamp into a stompbox as well. Actually, nearly all the builds have been done that way so far. We're slowly building a DIY'er community in that thread, and no questions are considered too basic or off limits. I have no financial stake, I just enjoy helping other people get into what has been a lifelong hobby for me.

The Passinwind Open Source Preamp

 

[BadExample]

^^^2nd that.

 

[tlite]

You might consider building up my open source onboard preamp into a stompbox as well. Actually, nearly all the builds have been done that way so far. We're slowly building a DIY'er community in that thread, and no questions are considered too basic or off limits. I have no financial stake, I just enjoy helping other people get into what has been a lifelong hobby for me.

The Passinwind Open Source Preamp

Looks cool. I may give that a shot as well! I have to work through that whole thread but appreciate the 'all questions are good questions' vibe.

(Oh, and for the record, I would have no problem even if you did have a financial stake- making money is OK!)