A Tale of Two Katana Boosts

In my previous Katana build I simply took out the parts for the charge pump, as I didn't currently have them in stock. I figured in the worst case scenario I could use an 18v power supply to get it where it needed to be. When I plugged everything in, I had one JFET that refused to work, but once it was swapped out I had a really nice two-stage boost. I still don't think it's on par with the genuine article, but it was a fun project. That being said, I still wanted to build one based strictly on the layout, so I ordered the parts and I set everything up.

While cutting the board it cracked across the entire top strip, so it looks a bit messy. There weren't too many parts affected, and they ended up working out just fine, thankfully. I did swap out the 2N5484s for J113s, because that's all I had. The one thing I found strange is the oddball JFETs I used in the 9v version didn't need biasing, they were already decently biased from the start. I did boost Q1 and Q2 to my liking, but with this second version it seems as if the JFETs knew they were supposed to be fed 18v from the charge pump, and required quite a bit of patience to bias properly. I like JFET circuits, but sometimes biasing can be a real pain in the ass.

Anyway, once they were biased I now have an 18v Katana clone. Does this one sound like the genuine article? *shrug* It sounds as close as I can get. I'm not running these through an expensive rig to test their full fidelity. I'm simply running them through a combo amp that farts out if pushed beyond 3 on the volume, just to make sure the circuits and their controls work properly. I do plan on buying two push/pull B250k pots for both the 9v and 18v versions, to give them a little more authenticity.

Being September, build season 2025 is coming to a close. I'm glad I didn't build as many circuits this year as I did in 2023 or 2024. I still have a handful of projects that need a parts order, so I know I'll have a few builds for next year. I hope the down shift in building continues in 2026, so I just build what I have, and maybe a few extras if something should pop up, but not going crazy like I did the previous two years. I keep saying this, and it never stops being true, but I need to focus on turning these circuits into actual pedals. Housings, inputs/outputs jacks, power input jacks, knobs, foot switches; all the things that make a circuit an actual pedal. I need to make all of my builds functional pedals. Then, that's when I get to use them!

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.