Calling all PCB design folk

Started by patrick398, July 27, 2019, 07:52:03 AM

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patrick398

After dipping my toes into the world of designing my own PCBs it's fair to say i'm hooked. I just boxed up the first circuit in a 1590B and ran into some problems which i'd overlooked. These are mainly to do with available space and board layout.

I have 4 board mount pots and a board mount DPDT. The board itself is 50x60mm give or take. For bypass i'm using a SPST momentary footswitch and a relay daughterboard which is 30x20mm. For this circuit i also wanted to use another SPST momentary for the tap tempo but i can't fit it in. After DC and Jack sockets i'm really not left with any room at all.



Do you guys have an tips and tricks for making the most of enclosure space? Or board templates for accommodating things like the enclosure corners or DC jack

I've toyed with the idea of using PCB mount jacks but i like the open frame nuetrik ones too much. Also thought about custom PCB shapes, adding 'cutouts' for where the DC jack and 1/4 jacks go. Not really much point for the 1/4 jacks since two jacks opposite are near enough the width of the PCB anyway. Maybe i'm trying to get too much circuit into a 1590B...but i've seen what your people do with 1590As, it's outrageous.


patrick398

#1
For reference here's the front:



See how the footswitch is too low down. The jacks are lower down than i'd like though not that important.
I could top mount the jacks but that would mean having the upper pot pins right at the top of the board, moving the PCB down about 20mm in the enclosure, probably still not enough room for the two footswitches and daughterboard

bushidov

I've been there. I had my own tiny13a board I made for my pedals, about that same size with my own firmware. But I still ended up going back to the smaller 3PDT switches with a PCB to hold it, the LED current limiting resistor and a P-MOSFET for reverse polarity protection (instead of a diode).

That all being said, here has been my rule of thumb:
1590A enclosures. Use the small jacks 1/4" jacks and use a 3PDT pcb schema as you'll need the space. If using alpha 90 degree PCB pots, maximum of two. They will have to be staggered with one turned upwards and the other downwards. I can get about 1.075 inches tall and 1.325 inches wide.

1590B enclosures. Use whatever jacks you want and keep the stomp switch schema small, but a relay board should be fine. I try to keep my PCBs no taller than 1.6 inches and no wider than 2.05 inches. I can get 3 pots easily into this format (usually staggering the center one a little lower than the left and right pots). I have crammed a 6 pot 2.075 inch tall by 2.05 inch wide PCB, but had the power jack on the side, used no PCB for the 3PDT switch (free wired it) and it was rather cramped.

125B enclosures. Use whatever jacks you want and keep the stomp switch schema small, but a relay board should be fine. In this case, I prefer top loading my audio jacks with the power jack and drilling nothing into the sides. This allows me to have a pretty large PCB aside from my stomp switch schema. I try to keep them under 2.2 inches tall by 2.2 inches wide.

1590B enclosures. Go nuts. My largest one there was a clone I made by tracing a Darkglass B7K. They used two PCBs and I wanted it down to 1. Using side mounted audio jacks and a top mounted power, I made this:



But those are just my personal recommendations.

I know if one does top mounts, you can even make the PCB extend down to the bottom of the enclosure, so long as a hole is left for the stomp switch schema, but I don't often run into that situation.

You can also do daughter boards if you really need to, but again, I don't often run into that situation in guitar pedals. Now at work, doing industrial electronics, yeah... I run into that all the time.
"A designer knows he has achieved perfection not when there is nothing left to add, but when there is nothing left to take away."

- Antoine de Saint-Exupéry

Mark Hammer

Jacks mounted along the rear skirt has been gaining in popularity...for several reasons.  First, it allows for pedals to be snuggled up against each other, conserving pedalboard space, and also requiring shorter patch cables.  Second, as more builders do it, being compatible with their form factor becomes more obligatory (i.e., everybody's doing it because everybody else is doing it).  Third, as bushidov notes, it also conserves space.  Since rear skirts on both 1590B and 125-B enclosures do not comfortable accommodate a pair of phone jacks and a power jack, power jacks will need to be situated on the side.

patrick398

Thanks for the replies!

I'll probably redesign the board at some point for top mount jacks, seems the best solution. Clearance above pots is enough in a 1590B right?

Doing this will push the board down by about 25mm, in which case there still may not be enough room for the footswitches at the bottom. I guess one option would be to use DPDT pcb mount momentary footswitches and incorporate them and the relay bypass onto the PCB itself and have a 'cutout' for the DC socket.

Hmmm, much swearing at Illustrator is about to ensue.

davent

#5
With the right parts you can cram the top pretty well with the power jack and two 1/4". This is a small board someone was kind enough to send me. My own boards i never use board mounted jacks, pots or switches so i've total freedom on enclosure design/layout.





https://www.diystompboxes.com/smfforum/index.php?topic=36392.msg1058847#msg1058847
dave
"If you always do what you always did- you always get what you always got." - Unknown
https://chrome.google.com/webstore/detail/photobucket-hotlink-fix/kegnjbncdcliihbemealioapbifiaedg

patrick398

Are they lumberg jacks? I've heard people mention them before. And i have some of those Dc sockets i think. If i remember correctly they only need a 8mm hole or something like that. They're tight as hell though, some plugs barely even fit inside

davent

The 1/4" are Lumburg's, the power jacks i'd purchased from various sources over the years.
dave
"If you always do what you always did- you always get what you always got." - Unknown
https://chrome.google.com/webstore/detail/photobucket-hotlink-fix/kegnjbncdcliihbemealioapbifiaedg

ElectricDruid

+1 for Lumberg jacks. If you need to save a bit of space, they're the thing. A quality part, too.

bushidov

I wish Tayda would stock them. Currently, I get them from Small Bear
"A designer knows he has achieved perfection not when there is nothing left to add, but when there is nothing left to take away."

- Antoine de Saint-Exupéry

Groovenut

Quote from: bushidov on July 27, 2019, 02:33:02 PM
I wish Tayda would stock them. Currently, I get them from Small Bear
Check out Love My Switches. They have them as well
https://lovemyswitches.com/1-4-mono-jack-lumberg-klbm-3/
You've got to love obsolete technology.....

PRR

> tips and tricks for making the most

PCB Layout For Musical Effects, R.G. Keen
http://www.geofex.com/bookpages/bookblurb.htm
http://smallbear-electronics.mybigcommerce.com/pcb-layout-for-musical-effects/

Not free, not a $2 book, may be more loot than you can spare. I have not read it. However of the very many layout books I have seen, I'm sure R.G.'s book would be the best for hobby pedal layout.
https://www.goodreads.com/en/book/show/15747109-pcb-layout-for-musical-effects
https://www.diystompboxes.com/smfforum/index.php?topic=58585.0
http://www.madbeanpedals.com/forum/index.php?topic=15240.msg143514#msg143514
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patrick398

Quote from: ElectricDruid on July 27, 2019, 02:21:43 PM
+1 for Lumberg jacks. If you need to save a bit of space, they're the thing. A quality part, too.

I've seen a few people reference them for saving space, but they must be the same length as 'normal' neutrik jacks, i mean the plug is the same length. From looking at them it seems they have more bulk than the open chasis neutrik ones?

Quote from: PRR on July 27, 2019, 07:19:15 PM
> tips and tricks for making the most

PCB Layout For Musical Effects, R.G. Keen
http://www.geofex.com/bookpages/bookblurb.htm
http://smallbear-electronics.mybigcommerce.com/pcb-layout-for-musical-effects/

In researching this i have come across a few R.G nuggets of wisdom, mainly the importance of establishing hardware layout before designing the pcb. This is something i didn't really do, so it's my own fault now haha.
I think i'm going to try and put together enclosure templates, import some hardware from the vector pack thats floating around the net and see what the best pcb layout is

bartimaeus

You can use plastic jacks like this one for top mount. Just cut away the plastic so that the enclosure still closes correct. Doesn't take much more space than the lumberg, since the plug is ultimately the same length. The main problem with open switchcraft jacks is the diameter of the outer ring.

https://www.taydaelectronics.com/6-35mm-1-4-stereo-phone-jack.html

GGBB

Quote from: Mark Hammer on July 27, 2019, 08:51:41 AM
125-B enclosures do not comfortable accommodate a pair of phone jacks and a power jack

It may depend on which 125-B. I've never used a generic 125-B, but I use Hammond 1590N1 enclosures and always rear mount all three jacks:




And here's one with two 3PDT footswitches, five pots, four LEDs and a battery:




I have a hunch that you could also use the 1590BS like this - it is the tall version of the 1590B and actually a hair taller than the 1590N1 although a bit narrower. The extra height of both over the 1590B can be really useful as you can typically fit jacks over/under the PCB (depending on component heights);

One thing to note about rear jack mounting and 1590B enclosures with respect to pedalboard space. I think a lot of pedalboard users prefer smaller pedal enclosures like the 1590B over the 125-B/1590N1 for space saving reasons. However, a 1590N1 with rear mounted jacks takes up far less width than a 1590B with side mounted jacks when you account for the space that the jacks and plugs consume (even if you use slim/pancake plugs and stagger them so they don't align and "stack up" width-wise). The enclosure width difference itself is only 5mm - less than one of even the smallest of plugs - and the mouths of the jacks will probably add at least 5mm.
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