When should I use PCB?

[wesman26]

Hey guys, I'm pretty new and very excited about starting up my first few pedals.  I spoke with good friend who has been circuit bending, modding pedals, and making his own for a few years now and I was talking with him about making a custom PCB (I recently learned how to make gerber files and what not at work and figured I could use the skill in my hobby).  His advice to me was to just use perfboard because it's easier to buy in small quantities as opposed to PCB which usually needs to be ordered in mass.  He also said that the time to switch from perfboard to PCB is when I start using IC's like op amps and etc...

The question I pose to you all is whether you agree with this evaluation.  Where do you all draw the line between PCB and perfboard?  And why? (The question of why is easily what I'm most interested in here as my curiosity in this new hobby of mine knows no bounds; don't be afraid to get technical, the more complex the better)

[theundeadelvis]

His reasoning makes sense if you are outsourcing your boards to a PCB manufacturer, but if you're just going to etch them yourself, then I would have to disagree. I make 90% of my pedals on self-etched PCBs regardless of size. I buy the 3"x4" copper blanks from Small bear for a $1.50 each and print as many layouts as I can on each board. I may get 3 or 4 boards out of one of the blanks, and then I already have PCBs etched for future builds.

The reason I prefer PCBs is because, if you're using a verified layout, there's a little less chance of error (in my experience) because you don't have to worry about incorrect traces like you would in perf. There are some people here though, that do amazing perfboard layouts of huge circuits (frequencycentral comes to mind).

[Ice-9]

Hi,
Your friend who has said perfboard is available in small quantities but PCB's need to be ordered in mass is probabally meaning if you order PCBs to made fro a manufacturer from your own artwork. There is no reason why you can't make one PCB if you are doing it all yourself. There are many different ways to make a PCB from start to finish and my prefered method is to use pre photo sensitized copper clad board, but other ways such as the iron on method are also possible.

I think what you have to ask yourself is do you just want to make an effect pedal you have seen (if so then just use perfboard or veroboard) or are you interested in how to design and make your own PCB's , I guess the choice is yours.

[Vince_b]

Actually I think that it is easier to use a pcb, you just have to put the components on the right holes and don't have to worry about how they will connect to each others (the pcb traces are already there!). You don't have to order in mass, you just have to etch your own. There are many tutorials that can teach you how. That being said, for a simple circuit it will obviously be faster to use a perfboard layout than to make a pcb but I still prefer a pcb because there is less probability of something going wrong.

[wesman26]

Would there be any sort of noticeable difference in sound quality?  Does using perfboard and wire lend itself to a greater risk of induction or other problems? 

Personally it seems like using perfboard would be easier since I'm designing most of my own schematics as it is and don't have any PCB layouts I'm going off of, so if I were to use PCB I would have to know which holes correspond to which path and how everything connects.

[Vince_b]

It won't make any difference in sound quality.
If you are designing your own schematic and your circuit don't have too many components, like you said, it will be easier to use perfboard. But if you want to build more complex circuits or circuits that already have a confirmed pcb layout, I think it will be easier to go with a pcb.

[amptramp]

Actually, there is an intermediate solution between perfboard and a custom PCB.  There are standard pre-patterned boards such as these:

http://www.sayal.com/ActionIndexP.asp?ID=47471

which have power busses going between pins intended for DIP devices.  Each pin of the DIP device is connected to the innermost of three holes that are connected by a trace.  Several companies carry these; Sayal is used as the example here, but most companies carry versions of these in several different sizes.  It is used for analog or digital designs and can eliminate 95% of the wire interconnects you would need with perfboard.  I have a similar board from a different manufacturer with different dimensions in work right now for a home-brew "fuzz to end all fuzzes".  There are more useful ones with four holes connected rather than three on each side of the power bus.  This would take care of 99% of all the wiring for most analog circuits but it needs more space.

[Gordo]

Oh come on, the amp guys get to have their mojo effect of tag boards vs. PCB's. Can't we do the same?

I digress, I've always found it easier to do a PCB, unless the circuit is small and I'm too lazy to etch. Vero and strip board completely eludes me so I've avoided them like the plague. It's cheap enough though to tackle a project of any or all of these disciplines and see what you feel most comfortable with and get the most consistent results.

[egasimus]

Etch your own PCBs. I personally use toner transfer a.k.a. iron-on. Finding glossy paper is what's most difficult to me, as my printer (a huge old HP LaserJet) makes photo paper fall apart, and also crumples up unevenly cut magazine pages. I've had good results with glossy cardboard. You could also use this stuff called "press 'n' peel blue" - it's made for this exact purpose, although I haven't ever had a chance to try it.

And don't waste your time with ferric chloride, either. I replaced it with HCl+H2O2 a while ago, and yesterday I actually did it in the correct proportions (2 parts 3% H2O2 to 1 part 30% HCl) - major improvement. Works like a charm, my board was done in about 5 minutes. Both ingredients are cheap and more available than FeCl. H2O2 (hydrogen peroxide) can be bought in drugstores, and HCl (muriatic acid, pool acid) in hardware stores.

[Mark Hammer]

1) It takes time and tools to produce and prepare your own PCB.  There are plenty of occasions where I look at the parts count, and decide that it will take me less time to put it together on perfboard than it will to get the PCB ready.

2) PCB layouts are predicated on certain assumptions.  One of those is the use of certain standard-sized enclosures.  Another is the use of certain component form-factors (applies most to capacitors).  A third is that the circuit is essentially "complete".  If you are using a chassis other than a Hamond 1590A, B, or BB, or if you plan to use one of those but your plans for control layout demand a different orienation than the board presumes (e.g., a two-fer in one chassis), or if you plan to add certain functions which are not included in the original, or if you are using components that do not match the space allotted for them in the layout, you may find it less nuisance to use perfboard thanthe PCB/layout available.

3) I cannot begin to count the number of times that I have "finished" wiring up a perfed circuit, only to be met with nonfunctionality when I plug it in.  Why?  Because during all the flipping back and forth a) a component lead fractured from the wiggling and I didn't see it, and b) keeping track of what things look like right side up and upside down led to confusion and the wrong things were connected to the wrong places/points.


So, to summarize.

• perfing CAN be less effort-demanding and more efficient than using a PCB....sometimes
• perfing CAN be more ideally suited to the context in which you want to use a circuit...sometimes
• perfing can more easily accommodate your component choices (or availability)...sometimes
• PCBs provide fixed connections that the builder doesn't have to "remember" or keep track of
• PCBs provide a certain stability that stabilizes parts and reduces lead fractures (though pad-per-hole can do the same)

[DougH]

The efficiency of PCB only really shows up when you are building multiple copies of something. IOW- populating a PCB that is already etched and drilled can be done a lot faster and more efficiently than building on perf board. But etching/drilling and otherwise preparing a PCB to be populated the first time is more work and takes longer than just using perf board. The fastest and least hassle way of doing this is to buy a pre-etched and pre-drilled PCB from someone like tonepad. This of course limits you to building what is available in this form from someone. I've done all three- etched my own PCB, used perf board, and built with a pre-etched and pre-drilled PCB. My rule of thumb is if it's a one-off (which my builds always are), just use perf. For one-off builds this is the simplest and fastest for me. If it's a more complex circuit such as a phaser or etc and it's just a clone of something that exists, buy a pre-drilled/pre-etched PCB for it if available. This will save you a lot of hassle in the long run. If you are building multiple copies of something, say more than 2, for your friends or whatever- then have a PCB etched or etch it yourself as that will be the least hassle for making copies.

[Earthscum]

Just want to add one to Mark's summary:

*Perf projects are easier to modify, in most cases, than PCB, i.e. You can sometimes find extra space to throw in a buffer that you may find you need, or add in extra clippers in board for clip-switching.

I make PCB's, personally, but I keep perf around for small stuff like Mill Bypasses and to use instead of having flying components when I do mods. Very handy stuff to keep around, for sure.

[ayayay!]

I rarely do more than one of anything.  If I do, then I'll get someone to make some PCBs for me, but I'm pretty proficient on perfboard. 

Here's my stink:  PCB's look great, but a perfboard is predrilled and you don't have to take the time to etch it.  So there are pros and cons to each, but I personally would get too bored drilling all those holes in an etched board.  And this is coming from someone who loves every step of building.  That just seems like a waste of time to me.   

[Mark Hammer]

I would concur with everything Doug noted, with one exception.

Hands up, all of you who perfed something and made a mental note to "run a ground/Vref wire over there, once you finished up this section" and then forgot to do it.    Keep 'em up while I count....57, 58, 59...no, no, keep your hands up, I'm not finished counting yet.....104, 105, 106......

The nice thing about PCBs is that, when the circuit starts to get complex enough, it keeps track of all the connections that need to be made, on your behalf.  If it's a 3 or 4 transistor circuit where it is a trivial matter to wire up the circuit on perf almost exactly as you see it, from left to right, with the ground on one side of the perf and the V+ along the other edge, then Doug is spot on.  For me, at any rate, once you start heading off into quad op-amp territory, and you find yourself deferring connections to ground or V+, or Vref until after you've figured out where to stick that 100nf  or 22uf cap that's a little bigger than wish it was (but it's the only one you had on hand), the manner in which a PCB "remembers" for you all those places on the board that need to be tied to V+, Vref, and ground, is a real godsend.

Ironically, if anything, making more than one of a circuit, for me at least, makes the perfing MUCH more efficient, since I know where everything has to go.

[DougH]

Right, Mark. When the circuit is complex enough to require routing on a perf board to be non-trivial- it's time to consider another method. When I'm building on a perf board I have a schematic on paper handy and I check off each node after I complete it. That helps me keep track of where I'm at and what is still left to do. The thing about perf board is you are routing the circuit as you go whereas with PCB that's already happened as part of the PCB design.

Incidentally, my perf board layouts tend to visually mimic the schematic as much as possible- ground buss on the bottom, power buss on the top etc. But I don't agonize too much about running jumper wires when needed in order to accommodate large or awkward shaped parts. And that's also the reason I don't use vero board- because it doesn't "look" like the schematic. It requires an extra translation step in my head to determine where everything hooks up. It's too confusing for me, but some people really like it.

[Mark Hammer]

Whenever I see an all-discrete circuit, there is a little knot in my stomach that becomes loosened, simply because such circuits lend themselves to the very logical (and literal) perf layout as you describe.

For those who do lean topwards perfing, I cannot recommend SIP op-amp chips highly enough.  They can provide tremendous flexibility with respect to where you locate parts.