Isn’t it awesome! I’m trying to have production cases ready for next weekend’s Experimental Garage Sale. I hope to see you there!
GetLoFi.com announced the 5th installment of the experimental garage sale. Read about it over there. Featuring lots of cool homemade gizmos, it should be lots of noise and fun. So mark your calendars. I’ll be set up there with my synths.
Rockit firmware 1.12 is available. The changes are mostly limited to MIDI. I’ve implemented a soft MIDI Thru. Messages not intended for Rockit, meaning on a different channel, are passed through to the MIDI Output. The MIDI channel can now be changed. To change the MIDI channel, hold down the Select button until the display starts flashing. Then, use the Save and Recall buttons to change the MIDI channel. Finally, hold down the select button until the display stops flashing and that’s it. Otherwise, I fixed a bug that caused the audio to stop when the arpeggiator was running and drone mode was entered. That’s about it. Some other transparent changes were made for an improvement in the number of clock cycles required to perform various tasks. Have some fun and let me know if you find any funny business going on. Download the hex file here.
Sprockit is now available in the HackMe Store. For now, it’s only available without the case, either as a kit or as a built synth. I’m hoping to get the case done soon, but I’m waiting on the graphic design from my better half, who has presently got her hands more than full. I will make the case design, sans graphics, available for those who will be making their own.
I developed a presentation as part of my Sprockit workshop. I think it’s a pretty clear presentation of wavetable synthesis and that it clearly shows how aliasing happens and how to avoid it. I’ve often found that it is difficult to find this type of clear and simple explanation of fundamental synthesis concepts that is particularly useful for the DIY Synth community. So, click through for some learning…
Some of you enterprising Rockit users came across some bugs in the the 1.1 code. I listened and have now fixed them. There was a bug in the pitch bend code that caused some screwy behaviour. I also made some more improvements to the filter envelope behavior. I think I’ve found the perfect filter envelope speeds. At the same time, I found a better value for a couple more resistors. R75 and R76 are going to be 18k from here on. This reduces the maximum filter resonance but it kind of had to come down a little since the level going into the filter from the VCA had been increased. It’s not 100% necessary, but I think it makes a worthwhile improvement. You can download the new code here.
I’ve been hard at work on Rockit’s firmware and am proud to put out Version 1.1. There are a number of improvements, bug fixes, and a new feature. I’ve also made a few adjustments/hacks to resistor values which greatly improve Rockit’s sound. Click through for a list of the software and hardware updates. Continue reading
The Rockit case is finally finished. I got the third and final prototype of the Rockit case in, put it together, and did the happy dance. I’m going to make some small adjustments for the production order, but nothing that will require another round of prototypes. I’m going to put up the case for pre-sale today. I need to hit a threshold of about 50 orders in order to buy it. The lead time from the laser cutter is three weeks, so these should ship in February. The cost will be $50. Click through for more pictures. Continue reading
Rockit’s getting a little brother, Sprockit. My goal with Sprockit it to take a lot of Rockit goodness and compress it down to something smaller and a bit cheaper. I’m achieving both goals by having a very dense design and by reducing some of the features. Sprockit is 4″x4″ versus Rockit’s 5.1″x8.6″, so it’s substantially smaller, like pocket sized (I would’ve called it Pockit Rockit, but there are some products out there already). There are obviously fewer knobs, LEDs, and switches. All of the control parameters are still there though and will be accessible via an external MIDI controller. The microcontroller is downsized from an ATMEGA644 to an ATMEGA328. I’m also incorporating a lot of the things that I’ve learned from doing Rockit and rolling those improvements into Sprockit. This image is my first prototype and I’m well into prototype two, which will be much improved. I’ll be doing a workshop with Dorkbot Chicago at the end of February where people can build Sprockit with me. I’ll probably do another Kickstarter project after that. I’ve learned from Rockit that I’ll need to get the case designed before I release it though. Click through for a complete feature rundown. Continue reading