150th Build: Bring On the Chorus!

My first guitar amp was a Crate GX-30M that had reverb and chorus, two effects that I didn't understand at the time. All I wanted was distortion; loud, obnoxious distortion. Reverb made it sound like I dropped my amp down a well with Timmy, and chorus made it sound like an alien was farting out what I was playing on the guitar. Needless to say, I never used them. Now I find myself building guitar pedals and experimenting with, and actually quite enjoying effects I've never used, or would have otherwise refused to use before. I've made many reverbs, I've made a handful of compressors, I've made a few delays and I've enjoyed the large majority of them. Now, the time has come to tackle chorus!

For a while I thought it was never going to come to fruition. Every DIY chorus circuit felt daunting, and I didn't want to invest all the parts that most of them require to end up with something that might never work, or I might dislike and never use. That was until I found the layout for the Madbean Glam Chorus on tagboard effects. It's simple, it's fairly low component count, for a chorus, and the controls were super simple. This chorus is PT2399 based, which luckily I had. I also was able to use one of the junk TL072s that I have, in place of the TL062. I had to order the 2N5457, but apart from that I had, or could make (spaghetti resistors for the right value) everything else. Once all the parts were bagged, it was time to build it.

This chorus tried to fight me, by which I mean I made some very rookie mistakes. I never order 16-pin IC sockets, I just ordered a ton of the 8-pins. For 16-pin ICs I use two sockets, for 14-pin ICs I remove a row, etc. While I was soldering in the sockets for the PT2399, I misjudged and soldered them one row too low. I'm glad I used 8-pin sockets, or else I would have to desolder all 16 pins and resolder it again. What I ended up doing was just removing (snipped them out entirely) the one row that was wrong, and I soldered in two single sockets at the top to make it correct. After everything was set I plugged it all in and away it went. I didn't even bias the JFET, it just worked.

With Rate and Depth turned all the way down there is a nice subtle shimmer, and with them both turned all the way up there is a very weird wobbly effect. With this chorus I find everything from completely off and completely up to be totally useful. This is a really nice, simple circuit, and a really nice chorus. It's not stereo, it's not feature heavy, but it does a nice job of giving a chorus effect that I find useful. What I once thought was impossible eventually worked out. I never gave up on the idea of building a chorus, and here we are. Again, it's not a perfect chorus, but the more I play with it the more I love it.