Clockworks offers open source modular analog and digital hardware for quick system prototyping and small volume applications. Sometimes we end up with extra PCB blanks from older hardware revisions and while we can't sell them as the latest and greatest there's nothing wrong with them either, so it seems a shame to put them in the trash.

What can I build with these?

The boards in this set can be used to make an analog prototyping system similar to the complete kit offered by Clockworks - for details check out the SYS01 system.

That picture shows Euro-block style connections, the input and output PCBs in this kit have RCA jacks (8 channels). Also the blanks do not include the supply, but you can get the 3 output supply as a kit here on Tindie too.

Once you assemble these PCBs you can build anything you want on the prototyping boards (and you can get more prototyping blanks if you need them). The prototyping board grid and trace pattern was designed with op-amp circuits in mind.

What's the prototyping part?

You can find details here, but the quick summary is you can stack the boards using pass through style connectors to get enough PCB real estate to put together 8 channels.

The standard supply routing includes +/-15, +/-5, 3.3, and 5V so can you put a mix of hardware together.

Maybe you can put these unloved PCB blanks to good use?

This kit is just a set of blank PCBs, you'll need to provide your own parts. Other than the connectors all parts are SMT, but they're all big SMT parts (mostly 0805) so it's not tough to assemble.

This is not a beginner project, you need to be able to read the BOM and schematic and determine for yourself how to assemble them. There's also a 3D PDF for each board that's really useful for figuring out where the parts go.

Tell me again what's wrong with these?

The two (identical) prototyping boards are current revisions and you can get the details here.

The RCA input and output boards have a goof - they use a Switchcraft octal RCA jack and the L and R pins are swapped on these older blanks, i.e. channel 1 was R (red jack), 2 was L (white jack), etc. Normal convention is channel 1 is L. But since this is an 8 channel board just call them channels 1 to 8 and you're good. Also some cosmetic issues with solder mask or silk screen (some may be green instead of white) and don't have a small secondary power and control connector that is found on the current version.

The carrier board that things connect/plug in to has two power connector locations swapped compared to the current board, and there's some cosmetic cleanups in the newer boards too.

Another difference is mounting hole sizes, current boards are designed for a M3 bolt, most of these have a larger hole that can be used with a M4 bolt.

It's not picky about the parts you use

The input and output boards have ferrite beads, caps, and small series resistors to reduce RFI. If you don't care about that you can just skip those parts - well obviously you need to bridge where the series resistors are. Likewise they have ESD diodes, but if you don't need those they can be left off too.

There are muting relays on the output board, don't need 'em? Then they can be left off too, along with the driver IC.

We do suggest placing the decoupling caps on the carrier board, but you can use pretty much any reasonable value.

All of the connectors are standard ones with all sorts of vendors out there for them.

So please, don't let these good PCBs go to waste

Yes, you could take the Gerbers from the design files and fab your own, but it's so much easier and faster if you just hit that little "add to cart" button.