Large circuit question

Started by MattAnonymous, March 14, 2004, 08:14:42 PM

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MattAnonymous

What's the best way to go about diy-ing a large circuit say something like a big muff and larger? (I mean as far as on a perf board).
It's people like us who contribute to dead fx pedals selling on eBay for what they'd cost new!

PB Wilson

I'm also beginning a larger than average perf-boarded project. I drew out the layout on graph paper using the point where the lines cross as the hole. I sketched it out a few times adjusting it for a size that will fit in the enclosure and having some space for the parts to fit without crowding. I think I'll mark the board on the non-copper side before adding components and double check before, during and after soldering. Good luck with your project.

RickL

That's how I do my perfboard layouts too. I like tight layouts because they're easy to fit into what ever size box I choose but the benefit of this method is that you can size the layouts however you want.

I use 0.5 inch spacing for resistors (i.e. lead goes in one hole, three holes in between then other lead goes in next hole), 0.4 inch for diodes, 0.2 inch for most caps (but check yours first) and 0.1 inch for electrolytic caps. Leave 0.1 inch of space on one or both sides of the cap to allow for their shape. If you can allow at least 0.2 inches of attachment length where wires enter the board, 0.1 will work but more is stronger. Resistor spacing can be smaller if you need it for the layout (or bigger I suppose) down to 0.1 inch if you stand the resistors on end but I'd stick pretty close on the others.

Check out R.G. Keen's article on PC board layout too, most of the info also applies to perflayouts.

BTW I use bare perfboard, not pad-per-hole and it seems to work okay. YMMV

ExpAnonColin

I haven't tried it but I always thought the most useful way would be to use someone else's design and basically just solder the PCB design right onto a breadboard, with solder inplace of the traces.  You could do it if you just sat down in front of the computer and concentrated.

-Colin

RickL

If someone has already designed a PCB layout and you don't want to etch a board try the 4ms CBCB method of contruction. Essentially what you do is glue the layout onto a piece of whatever you want to use as a board (CBCB stands for cardboard circuit board - it works but I prefer to use the stuff that's used on kitchen counter tops), drill the holes, insert the components from the other side and connect along the layout traces with the component leads and extra wire if neccisary. Note that you'll have to mirror image layouts that are designed for use with PNP for this to work.

I've built dozens of effects this way, from simple boosters on up to a Craig Anderton Quadrafuzz and I am very pleased with the results. I keep meaning to try etching a board but I rarely make more than one example of any effect so I still haven't got a round tuit.

javacody

RickL, what is the stuff that is used on  kitchen counter tops?

Travis

Colin, that's OK on bare perf, but on pad-per-hole it is a bit dodgy to wire between pads.  If the wire needs isn't elevated, the wire path needs to be given greater space.  

Most of GGG's circuits work well on perf, but Tonepad stuff needs to be restructured or treated three dimensionally.

RickL

It goes under several names. Formica is one I think. It's the plastic laminate that is used on almost every kitchen counter top. You can get small sample pieces at Home Depot and the like for free, or just buy a 2'x4' piece for a couple of dollars and you'll have enough for a couple of dozen boards. Another option might be to check with a company that manufactures and/or installs kitchen counters and ask for their scraps. An 8"x3" piece is garbage to them but will make you 3 or 4 boards.

Cardboard will work too (use an old cerial box or similar) but it's not as sturdy. I suppose really thin wood laminate would also work or any type of thin plastic but the Formica(?) is designed to handle a bit of heat and it's cheap (or free), sturdy and can look kind of cool if you get something with an interesting pattern.

freeradical24

are there any computer programs for designing board layouts?

Mark Hammer

Enter PC layout software into Google and you'll find lots.