My first pedal project (smd) with pictures

[soulsonic]

Respect!

[newfish]

Man!  That's impeccable!

That's the neatest thing I've seen in *ages*!

Congrats!

[snap]

Nice work.

The thing I hate about SMD is that film caps don't shrink like silicon and resistors do. You're stuck with having to choose either ceramic caps, huge nominally surface mount films, or a hybrid surface/through hole board.

e.g. Farnell has:
http://industrial.panasonic.com/ww/i_e/21088/smd-film-capacitor_e/smd-film-capacitor_e/ecpu/index.html

[Ice-9]

Yeah ! i like your idea roger. Using a socket and plug on the wiring harness at one end will allow the quick swap of different types of fx board. I think i will keep the pots mounted to the fx pcb and just have the connection betwen two pcb's. thatway i keep the fx circuitry complete.


Thanks for the farnell link Snap. i will check out the uk farnell web site for these.

[ambulancevoice]

reminds me of those MOD boards
great job, do you use a typical soldering iron or a special one/modified one???
+
if i were you, id solder some jumpers across the back of the pots and wire it to the input jack ground

[Ice-9]

Yeah, i use a normal soldering iron , no mods just a standard antex 50 watt. Great idea about grounding the pot cases also. Something i totally overlooked.

[R.G.]

Farnell has: http://industrial.panasonic.com/ww/i_e/21088/smd-film-capacitor_e/smd-film-capacitor_e/ecpu/index.html

Yeah, I know they exist. I use them all the time.

My point was that a film cap is roughly the same volume (length x width x depth) for a given value of capacitance whether it has PCB mounting pins or metalized end caps. So a 0.1uF film cap will be roughly the same volume whether it has pins or not. Perhaps even worse for the PCB layout guy, a through-hole film cap is always turned so it stands on the thin side on the PCB. For SMD, the cap MUST be oriented so the maximum-area side is down to ensure it is held firmly to the board. So an SMD film cap takes up as much or MORE of the board area than a through-hole cap of the same value.

This is particularly frustrating when a resistor has shrunk from  a footprint of 0.1" x 0.4" (0.04in^2) to 0.08 x 0.05 (0.004 in^2), or by a factor of ten. And when resistors as small as 0.02" x 0.01" (0.0002 in^2) are available, a factor of 200 smaller.

[puretube]

0805 ain`t that large...

[earthtonesaudio]

The 4-wire thing reminds me of the little Danelectro Fab series.  Same deal with the switch and jacks on one pcb, and the effect on another.

One question:  do you feel like the in/out jacks are solidly connected?  In other words, would you worry about repeated plugging and unplugging causing them to come loose?

[waveman]

Wow, that is sweet!

[Sweetalk]

Really nice looking pedal... my question is... why smd??? just for fun?

[R.G.]

0805 ain`t that large...

Unless my calculator has been making gross missteps, it is - 0.6376 nano-Acres, 0.258 nano-hectares, 2.58 mega-microns squared.

I'm pretty sure I have area in "hides" in here somewhere....   

[PerroGrande]

Nice job on the SMD build.    I've converted a lot of my builds to SMD.  Once I got the hang of how to solder the devices, etc, it actually goes fairly quickly.

The devices that are the biggest pain to me are SMD electrolytic caps.  They come in seemingly endless varieties of sizes for a given value which, of course, changes the design.  Plus, I find them to be the most difficult to solder securely.  Tantalum caps are far easier to solder, at least for me.  Mixing through-hole caps is easier still, but now the "back" (nee front) has components as well.

[Ice-9]

@ earthtonesaudio , The jacks and switch are secured to the metal case the same way a wired build would be meaning the pcb and solder joints take no pressure at all. the board is really susspended from the components rather than kepping the components in thier place.

@ waveman, I just bought a evh phaser from mxr and took it apart to check out the circuit and seen it was 99% smd and looked really neat , so i thought why not build an smd fx myself  just to see if i could. Then i realised that it can give so much more scope as to what you can fit in a box (and the components are cheaper and there are no holes to drill in the pcb apart from the pots) now i have the smd bug and want to build them all like this.

I made 2 circuits for testing 1 smd and 1 normal components and to be honest i cant hear any difference in the sound from the 2

[Ice-9]

One more photo of the fully assembled and tested pedal. Just needs a paint scheme now. Spose its time to move onto a new pedal now. Hmm phaser or flanger ?or maybe a smd BSIAB2 poss with 3 band marshall style tone controls.

cya all in the next build.

[earthtonesaudio]

Okay, one more question:
How did you get the Jacks/Switch pcb in the enclosure?  Since the jacks stick through the sides, don't you have to bend the board quite a bit to get the jacks through the holes?

[Sweetalk]

If you use those ALPS or ALPHA mini pots you can put several more knobs in there, taking advance on the tiny smd board!!. Very nice build!

[Ice-9]

The jacks are not the type that stick through the holes. they like up exactly with the inside of the case then a chrome threaded net scews into the jack internaly. i will post a pick of this when i get to my home pc.

The pots i have in there are alpha minipots and probs get 6 in total in there for any fx that need that many. Im thinking of doing a 3 band tone and gain and level next so that makes it 5 for my next pedal. I will see how that goes.