Don't Eat Yellow Snow (SMD)

[stevie1556]

So, my latest SMD board works! Can't wait to get this one boxed up! Just tried it on my testing rig/box, and it's absolutely beautiful!

It's essentially a Lotus Pedals Snowjob, which is a underdrive (marketing hype I think), and has a switch to go from normal mode, to what I can tell is diode clipping to get a more harmonic effect.

Here is a YouTube video I've found of it http://youtu.be/VxQ73v9-BXg

[cooder]

Hmmmm .... yummy yellow snow with little particles on it... must lick on it....

[muddyfox]

Nice one, Stevie! The color certainly fits! 

Looking forward to building my own...

[culturejam]

Nice!

Is C1 a capacitor "teepee" ?? If so, that's pretty diesel.

[cooder]

Where would I find a schematic for this? Or could you post it please? Cheers

[stevie1556]

Cheers guys

Culturejam, how do you mean by teepee? It's supposed to be 120n, but I didn't have that so I have to stick a 100n and 22n together, which has worked.

Cooder, there was one a while ago on FSB, but it's gone now, so I had to use my schematic and the layout on Tagboard Effects to get the component values (as I never include them on schematics). Here is a picture of the one I've got on my laptop though.....

[culturejam]

Culturejam, how do you mean by teepee? It's supposed to be 120n, but I didn't have that so I have to stick a 100n and 22n together, which has worked.

That's exactly what I meant. Nice work!

[pickdropper]

Cool build, Steve.  Nice SMT work.

A bid  of an aside, but I actually think tombstoning SMT caps can be fun in an odd sort of way.  We should have an entire thread of oddball PCB workarounds.  It can be interesting to see how other people tweak their boards.

As far as SMT reworks, this rework wasn't quite as enjoyable as most:



/threadjack

[wgc]

That's a spacious build!

I usually just solder the cap flat to the pcb and then solder another on top.  Fortunately don't have to do that too often.

[culturejam]

I usually just solder the cap flat to the pcb and then solder another on top. 

That works for parallel, which adds values for caps. What Steve actually did was put them in series, so the 100n + 22n yields a net capacitance of 18nF.

[cooder]

Cheers guys

Culturejam, how do you mean by teepee? It's supposed to be 120n, but I didn't have that so I have to stick a 100n and 22n together, which has worked.

Cooder, there was one a while ago on FSB, but it's gone now, so I had to use my schematic and the layout on Tagboard Effects to get the component values (as I never include them on schematics). Here is a picture of the one I've got on my laptop though.....

Thanks for posting schematic, would you have a BOM / value list as well please? Might do a layout myself of this, thanks.

[stevie1556]

Forgot to mention in the first post, I hand soldered this board using 0.3mm solder, rather then using the soldering paste and hot air gun method.

WGC - Thankfully, I have most of the component values I need and don't have to do it too often either It's only that spacious because I like have the pots board mounted, although I do need to make a slight revision to the board (one of the taces needs removing from the back and replaced with a wire as it crosses another trace.

Pickdropper - That workaround with the caps under the legs is bloody genius! Are they 0603 size as they look really small!

Culturejam - I've just double checked my board, those caps are definitely running in parallel.

Cooder - the part values are:
R1 - 1M
R2 - 5K1
R3 - 2M2
R4 - 3K3
R5 - 390R
C1 - 120N
C2 - 47N
C3 - 47U
D1 - 1N4148
D2 - 1N4148
Q1 - 2N5088
Gain - 250KB
Vol - 250KB
Switch - SPST

If you want to build it on stripboard though, the layout is here http://tagboardeffects.blogspot.co.uk/search?q=snowjob

[pickdropper]

I usually just solder the cap flat to the pcb and then solder another on top. 

That works for parallel, which adds values for caps. What Steve actually did was put them in series, so the 100n + 22n yields a net capacitance of 18nF.

I think they are parallel just on their sides instead of stacked.

[culturejam]

My bad, it looks like they are end-to-end to my squinty eyes.

[cooder]

My bad, it looks like they are end-to-end to my squinty eyes.

That's the blimmin' problem with smd... they are so feckin' small...