Bring out yer Diptrace
- Thread starter Grubb
- Start date
Bio77
Well-known member
Thanks! This was the most complicated one I've done, so far. I planned to use the space between the PT2399s as routes for the power, but I forgot that since they are SMD I would need via to connect to the back copper layer for the signal traces. It was a nail biter in a couple of spots, but I got everything crammed in. We'll see if it works, this weekend
Bio77
Well-known member
That looks pretty good, where's the struggle?
dan.schumaker
Well-known member
SMD can be a whole different beast. Its like going back to single sided layouts. No good tips here, just keep at it, the more you do it, the more and more it makes sense.
vigilante398
Authorized Vendor
A lot of the tips for through-hole boards apply just as much for SMD,
- parts placement is key. Group components based on function for easy routing. If you're spending more time on routing than you are on placement, then your placement isn't good enough. Good placement makes routing easy, bad placement makes routing difficult or impossible.
- it's common to want to squish everything together because they're small, but you need to make sure you leave space for routing between and around components. This is especially important if you're going to be hand-soldering them as you need room to get the iron in and you don't want to be accidentally bumping other components. I have an added mechanical layer in my SMD footprints with a border around them for minimum required spacing to make sure I don't put things too close together
- don't be afraid of vias. They're not always necessary on through-hole designs, but on SMD designs they're necessary. The design I posted above has 167 vias.
- tent your vias. Good practice in through-hole as well, but especially in SMD where you may have vias close to solder pads, tenting vias ensures you won't accidentally get solder bridges between pads and vias.
flemming
Well-known member
Any reason for not using a copper pour for GND?
Grubb
Well-known member
Yeah I do similar, set it to "unpoured" so that I can see things well. Also handy when checking the 3D model.
Grubb
Well-known member
So I borked up a build I am working on using one of my own boards. When it didn't work I started troubleshooting, but my troubleshooting turned up no clues. In going back to my Diptrace files and the original schematic I was working from, I can see that I accidentally left out a 1K resistor going from Vref to a net of capacitors. To fix this pedal, I will need to physically connect the Vref net to one of the caps via an offboard 1K resistor. Can anyone recommend a good way of attaching/soldering an offboard resistor? Preferably under the PCB 
vigilante398
Authorized Vendor
Piece of cake on through-hole, just "surface-mount" the resistor leads between the two points that need to connect. On surface mount it can be a little trickier, but if you have a pad that at least one side can go to you can solder down one side then "float" a wire to the other side to connect to where it needs to go. When I tack on SMD passives like that I generally apply a dab of epoxy (or hot glue in a pinch) for strain relief, just in case.So I borked up a build I am working on using one of my own boards. When it didn't work I started troubleshooting, but my troubleshooting turned up no clues. In going back to my Diptrace files and the original schematic I was working from, I can see that I accidentally left out a 1K resistor going from Vref to a net of capacitors. To fix this pedal, I will need to physically connect the Vref net to one of the caps via an offboard 1K resistor. Can anyone recommend a good way of attaching/soldering an offboard resistor? Preferably under the PCB
dan.schumaker
Well-known member
I got my proto boards of this in, and it sounds awesome! The ghost feature is pretty cool, and I still plan to try it out with a MN3008 in the second position to give some more rhythmic delays.
I did have one issue, I forgot to ground the compander! After connecting it to ground, it works like a champ. Stupid mistake. So while I was updating the board, I thought to myself... there is no way I can add modulation, right? Right? Well, a little work later, and here we are
With the little work of hand soldering an IC and 3 SMD parts to the top, I'll be able to have 600ms delay and modulation, pretty cool!Attachments
Bio77
Well-known member
Dan, you and thomasha are headed to the Thunder-dome!I got my proto boards of this in, and it sounds awesome! The ghost feature is pretty cool, and I still plan to try it out with a MN3008 in the second position to give some more rhythmic delays.
I did have one issue, I forgot to ground the compander! After connecting it to ground, it works like a champ. Stupid mistake. So while I was updating the board, I thought to myself... there is no way I can add modulation, right? Right? Well, a little work later, and here we are
vigilante398
Authorized Vendor
Per my post in the "must build" pedals thread, here's a Soldano GTO layout I put together. I liked the idea I had a bit ago of mounting the PCB vertical in the enclosure so the tube goes horizontal and stays inside the enclosure instead of sticking out the top. It limits the amount of space I have to work with on the layout, but this should fit in a "landscape orientation" 1590BB.
flemming
Well-known member
I've yet to send any layouts out for manufacturing (soon), but I've put a couple together now and clearly I let my level of confidence get away from me a bit. I was looking at the Spaceman Gemini IV and DeadendFX has it in a 1590bbs and after a quick glance I thought, "sure no problem, I can get this in a 125b". Only after I started working on it did I realize that it had 6 pots, 1 switch and a transformer. But I think I got something that fits. I replaced the MOSFET polarity protection with a diode to cut out a few components. I could have probably dropped the ferrite beads too, but I kept them. There may be a little tweaking left to do, but I was kinda proud that I squeezed it all in there. I never claimed to know what I'm doing so I'm not sure if I made any faux pas from an electrical standpoint.
flemming
Well-known member
I've did a few simpler layouts beforehand, but I've been sitting on them to save a few bucks on shipping. Also I never said any of them worked, so there's that. I'll keep my fingers crossed.@flemming I can't believe this is the size of the first project you're sending off! My first PCB project was an Em-Drive, it had about 10 parts total and it still didn't work properly
Nice work mate, I hope to see a future build report with this board.
Passinwind
Well-known member
I hate getting back coasters. The pricing structure at JLCPCB always makes me tempted to buy 15 or 20 boards even when the design isn't fully vetted yet.I've did a few simpler layouts beforehand, but I've been sitting on them to save a few bucks on shipping. Also I never said any of them worked, so there's that. I'll keep my fingers crossed.
I'm digging this thread and this forum a lot since pedals are mostly a new direction for me. The vast majority of my board layouts have been onboard preamps and the rest have been for various bass amp and preamp builds I've been doing over the last ten years.
So this would be a typical onboard preamp layout in my world:
I've been using KiCAD for about ten years now and tend to make and use my own component footprints most of the time. That particular board came from DigiKey's DK Red service, which is priced similarly to OSHpark but has a few different spec limits. Biggest difference is that they don't accept plated slots, and that does matter to me a lot occasionally.
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Harry Klippton
Well-known member
Now I know who to direct my stupid kicad questions to
