x0xi0 #330-133.5 : Full Build. Next Steps

The x0xi0 mid-build in 2011.

As you can see, this x0x build hit a wall. I followed through the original documentation and built the whole kit in place of doing it in parts. I then had to shelve this project since there were some gaps and errors in those PDFs. I've done numerous other projects since.

A recent x0x repair for someone else inspired me to finally put this project to rest. This has turned out to be advantageous since Brian's documentation is now into its fourth revision and appears to be quite complete. I've been able to do a sweep of updates with little risk and the results have paid off.

2014. It looks sad now but all will be well soon.

So, now that I've reviewed where I left off, here's where it stands. In the interest of extreme experimentation I've socketed most of the transistors and a few key components:

• R47: This extends the low range on the x0xi0
• R61: this controls the ENV MOD setting when Brian's pot is set to 0. 10K is the default in the document.
• R97: as per my original build, this adds a 'natural' boost to the resonance. Some people add a pot for this. I don't see the point. 10K is what's in the document. My last build provided boost at 9.2K. My final decision for this build is pending. What I want is the same behaviour as the the last build. 90% turn in the pot gives my a proper 303 calibration. The extra 10% is the boost and nearly reaches self-oscillation. More than enough for me!
• C21: This add more bass boost and in this case has an effect on VCF Out as well.

The LEDs were also never placed so this task is under way now. here's a dorky photoshop file I've kept on hand to experiment with color combinations:

I'm using the same set of LEDs as the last build but different values appear to be useful here. These will be more intense than the first build but I have time to try out a few combinations.

5mm:
Blue: 5.6K Ohm
Purple: 100 Ohm
White: 2.2K Ohm

3mm - pending delivery of custom LEDs:
Blue: ?
Purple: ?
White:?


There's also loads of wiring to finish up. My pre-assembly calibration succeeded though. VCO, VCF, and ENV all check out.

It's getting there. I want this finished so I can finally have some fun with it.

x0xi0 #330-133.5 : I/O Mod Board

Now that 99% of my parts were here I couldn't resist and got started on the new build. I spent the first while organizing some of the parts (especially the resistors), reviewing the documentation, and taking notes on some of the support issues a few builders have a come across. At the moment it's a bit of a sea of confusion in some areas but the I/O and Full mod are well documented. The custom PCBs for the main x0x, not so much. Brian suggested I get started on the mod boards first so I took the advice when it was given :)

Generally speaking it was a relatively painless task but a few things cropped up. I've made a habit of socketing ICs and transistors but the layout and spacing for some of these parts doesn't really allow it without making very specific cuts and sizes on the sockets. Working on the I/O was a good introduction for what's to come. In future I'll need to try surrounding parts and see if it even fits. Some of the transistors are also not set up in a linear configuration so a basic socket strip that's been cut won't work. The BC547B has been set up this way. That's a bit disappointing but again, at least now I know that this is the case. Since I'm using the custom PCBs the power supply is being installed there and being left blank and omitted here.

So all in all ~ this build needs one's utmost attention!

x0xi0 #330-133.5 : Step Zero

In fall of 2009 I started to get the itch to take another run at a new x0x build. My intent was to build 2 or three of these anyway so Brian Castro's x0xio kit was the right fit: it's more complex, expands the x0x's capabilities, and still retains the original clone's accuracy in the process. He also produced a first run of custom PCBs in April 2010 specifically for his mod so I'm among the first five or so builders putting it together. Needless to say I'm an early adopter on this one! As such the documentation is still incomplete. I'll need to tread carefully so I don't botch up the project. My kit arrived at the beginning of June. It was a patient wait but well worth it.

Goals for this project

Just the x0xio kit. The main board an I/O are equally large as the spread in my self-sourced build.

My goals are somewhat similar to my self-sourced x0xb0x. I still want to maintain some control over the final cost. I managed to avoid several suppliers by using reliable alternatives: James from Willzyx, the new x0x supplier taking over for Adafruit, Brian, the source of the mod itself, and my local electronics supplier. I'm also able to spread some of the costs from my original self-sourced x0x since I purchased parts for multiple units at that time. This project is primarily based on BOM v2.1 and a dizzying list of mod parts from the x0xio site. I'm less concerned about the hours spent this time around, though I may choose to keep tabs on it.

The serial number

Between my self sourced x0x and this modded one, I also came across an incomplete original run x0xb0x, number #330. It needed repairs, testing, and the like. I was able to get it back up and running with a fair bit fussing around. I decided that #330 could be used as the core for this build. The x0xio is dramatically different but I think it'll be worthwhile to have key parts of the original kit be used here. This way its roots are still planted in adafruit territory. So the number represents #330, #133 of the x0xio kit, and number 5 for the custom PCB set.