CON BRIO GATE: Boards Redesigned to eliminate fixes, trace cuts, bodge wires and other Problems. Works!

Boy Howdy! The ConBrio Gate Generator appears to be one of my more popular projects to date, based on blog post hits. However, the original schematic had a lot of mistakes.

Let's redo the board to fix the mistakes. 

Poof--DONE. Redesigned, new one worked without fixes on my bench.

To summarize, this is a +/- 15V synthesizer module that generates gate signals that speed up or slow down based on input data, think of a bouncing ball running out of energy, for example.  

Parameters can be controlled via gate and CV, and a degree of randomness is built in.

For the background on the module please see the original post here; you can hear what it sounds like here.

Better Never than Late: It took me about two years to finish redo/PCB fix. Thank goodness it's done! Get code, schematics, PDFs, wiring diagrams, BOMs etc. from my github, here. You can also see a "project" for this featured on my generous sponsor, PCBWAY's, project site, where you can download the gerbers and/or get the PCBs fabbed, here.

Let's build!!!!

Boards arrived from PCBWAY post-haste....if you need some PCBs fabbed, please help support this geeky blog and check out PCBWAY.

I chose to design 2 PCBs for this project--a main board for the nano and its buffers, and a board for PCB mounted pots and jacks. Hook up wire is used to connect the two.

 

Construction was straight forward, no real issues, although I didn't label the wirepads on one board to entirely match the other pcb, which was dumb. Maybe in a future revision? At this point probably not, but I have posted a wiring diagram on the github. 

Front Panel fabrication used a blank Frac 1U PCB and the construction techniques mentioned here and here:

Jacks were placed on POTS PCB, front panel fit, and then the components were soldered:

Next, I double checked the fit then soldered up the hookup wire:

Then I removed the front panel and cut and applied the vinyl label:

Some touch up, clear coat, and other tweaks, tests, and by Gates, we have a decent looking and good working module:

About the redesign: The main "nano" board is more complex than it needs to be. For example, for the transistor buffer for "Rev in" input I used 2 3904 stages; one transistor would have worked along with some simple code modifications. I wanted to have an "inverting input" for "REV IN" on the front panel but ran out of room so it was omitted. This could be easily implemented down the road but would require more front panel space, something becoming hard to find in my ever growing modular rig.  

Also when I first powered this up to test I found that the output and inverting output seemed to lag a bit. The output should have gone from 5V to 0V immediately, but it was more like a few milliseconds for the 5V to make it back to 0V. I remembered that fet based op amps have this issue at times when in series with other CMOS pins, such as what you see on a Nano.  

An LM324/LM358, which has slightly lower input impedance, solved this issue, so that what I used.

Brio Con Leave oh: That's it for this post. I start a semi-lengthy vacation tomorrow, and I haven't had any time off for a really long time, so there might not be a lot of posts in January. But I'll be back.