Tuesday, May 13, 2014


After sitting for about a month with several issues, I finally finished the Mini-Meanie (sort of)! I finished the build quite a while ago, but I was waiting on the "rare" parts to become available at Thonk. Impatiently I ordered everything from UTSource. After I installed the key parts, I found that 1 of the 4027 oscillator boards was DOA and VCO 2 was not outputting the Tri/Sine waves. I scoured that damned PCB looking for either a solder bridge or the wrong part. I checked every component 3 times each looking for something misplaced, but it all looked ok. Figuring it was a bad part from UTSource, I shelved the TTSH until the Thonk stuff arrived. While I waited I worked on the clock bleed by removing the LED blinky transistor for the S&H rate and did the jumper fix. This got most of the bleed, but it is still there unfortunately. For now, setting the rate to max keeps it unnoticeable, but I want to figure this out eventually. I did try several different power supplies as well as my bench top supply and none of it fixed it.

Last week the Thonk kit came and I finally had some time over the weekend to start looking at it. First thing was the 4027 board. I pulled out the fancy trannies and put in the Thonk ones. The 4027 was still dead. About this time I started really freaking out. How could something with barely any parts not work! It couldn't be a resistor or cap.... oh wait, maybe the 3906/3904 is bad! I pulled them out and dropped in 2 new ones. There it was! Bummed that I sacrificed some of the rare parts, but, good to know the UT stuff wasn't bad. Keeping this in mind, I pulled out the 3904's in the VCO 2 circuit that's part of the Tri/Sine wave. Again, problem solved!

One last thing was the filter cutoff would raise the pitch of the VCO's as I would raise the cutoff. Another headpounder which ended up being that a keyboard CV needed to be applied. I know that it's mentioned to add a jumper to short the CV to ground, but that didn't change the issue.

To Do is add the reverb tank (which is on order) and add the 2 speakers, which I'll do eventually but it's not a priority for sure. Lastely I'd like to add a MIDI 2 CV internally. Right now I'm using my Kenton Pro Solo, which works great because it can send the gate and trigger needed for the envelopes to fire. I have a midimplant I could add, but I'd need to make a gate to trigger converter. Not hard, just not wanting to do that at the moment.

Below is a quick video of the first patch. It's annoying and ear piercing and sounds like a Tron junkyard bike race, but, it was fun to patch and mess with nonetheless. Soon I'll put together a proper demo.

As for building these: I'll do it, but the availability of future batches is really up in the air. There were some serious issues with the logistics company. They damaged a large amount of the cases and panels (mine being one of them). I know the issue has since been addressed and corrected, but there has not been any word of a new batch being processed. We shall wait and see.


  1. did you manage to fix the left over clock bleed after the mod? mine is the same as yours in that I can still hear the bleed after the mod, less than before but still there making it unusable.

    1. Since I posted this, this was developed: http://www.muffwiggler.com/forum/viewtopic.php?t=116172&postdays=0&postorder=asc&start=0

      They are OOS right now but it looks like he'll be making another batch. I did this to mine and it completely got rid of the clock bleed and I was able to put the blinky LED back with no issues!