Meatball / McMeat Layouts with on-board switches

[ringworm]

You're correct on the trace between the the colour and intens pots, cheers for the pointers with this. That was a hard spot to trace as the photo of the pcb is a bit vague in that area. I'll update my pics again.
Smallbear carry the switches ok http://www.smallbearelec.com/Detail.bok?no=46
I get them in the UK from Bardwell cheap enough.

[Brymus]

I just read this thread,and the Spanish psssi one too,
and wow after listening to the clips from the Spanish page I want to build as well.
Have the layouts been corrected?
or is the latest one that was posted corrected?
I think I will etch this in the next couple of weeks,good work to BTW.
I cant believe this was someones first build in the begining of the thread.

[ringworm]

My layout and pcb on page 3 have been updated and corrected. The wiring diagram on page 4 has not been tested yet but should be good as it's straight from a gutshot.
No builds have been verified as yet.
Resize the board to 181.51mm x 92.96mm @ 300.025 dpi

[ChanchoPancho]

I built it with my layout, that's basicaly rigworm's layout with thicker tracks and pads. One thing I forgot to tell in previous posts is that i added two extra set of pads to add a couple of C's in the switch 3 so that no switch posistion is wasted.

Well, it's been like a week since I populated the board and corrected some things that I posted in earlier replies, but still doesn't work. The signal doesn't trigger the effect. It filters but the green led (LED3) is always on, even with no input signal. The pots are working (I measured voltages) but I'm not getting any filter change. The optos are ok 'cause i measured it's resistance. I'm still debbuging but if I find something else i'll let you know. Have anyone else had the same problem? Did you solve it?

[ringworm]

Sorry to hear this isn't working. I've been looking over the schematic and see I also have lug 3 of the intens pot connected to lug 1 of the colour pot. Again I think the pcb photo is unclear here while the schemtaic shows no connection between the two as far as I can tell. Maybe the traces should look like this instead?

[ringworm]

Also could the positions of R6 and D3 be switched? Or does it not matter if they are connected in parallel?

[Brymus]

I am gonna wait until you guys get this verified as I am a "paint by numbers" builder.
But man I LOVE the way that pedal sounds,I definetly want to build one.

[ChanchoPancho]

Also could the positions of R6 and D3 be switched? Or does it not matter if they are connected in parallel?

I think there aren't switched. They're soldered in parallel in the same pads. I think they forgot to make one extra set of pads in the original layout.

You're right about the colour and intensity pot's I will correct that in my board.

[ChanchoPancho]

Finally it's working!!!  I have to check some details and then I'll post my final version of the layout.

[Skruffyhound]

Congratulations, good work.

[Strategy]

woohoooo!!!! well done! 

[ringworm]

Finally it's working!!! 

Awesome!
I've tweaked and updated my own pcb on page 3 so they'll both be good to go. I'm gonna give this a go in February once I get my thesis out of the way in Jan.
if you come up with any more tweaks let us know.
I'd like to figure out what the resistance of the original LDRs was or if they were matched. Not sure what the sound difference will be between building it with Vactrols or doing the LED/LDR thing. Anyway...

[jota.ventura]

Hi.
I decided to take the easy way and draw the pcb directly from the photo:


I distorted the image to make it rectangular, then I draw the traces and the jumpers, looking at the schematic and the other photo.
It only needs to be rescaled and place the components and cables in their places.

[ringworm]

You'll also need to flip the image horizontally if your doing a press'n'peel.

[ChanchoPancho]

I also recommend that you add extra pads below the 1458 because R6 and D3 are soldered together in the original layout.

[Skruffyhound]

OK it's time for me to ask a possibly stupid question here. It's been bothering me that especially the lower 2 rotary switches have very few poles used, if I am not going to be a purist about this ( and I'm not, at least for the one I build for myself ) wouldn't it make sense to change them to toggles and jiggle the traces a bit to make the whole thing a bit smaller. Don't get me wrong, it's great to have an almost "original" and verified PCB layout, I'm sure I'll use it in the future too, there's just something about all those unused poles .....
Maybe I'm missing something, or maybe I should be content to add a few caps to switch three and shut up
Thanks for all the hard work boys.

[ChanchoPancho]

I thought of that but I realized it is the best to use the same kind of switches because later it'll be simpler to fit into an enclosure panel. The first option i though is to use typical toggle switches but i found 2 problems: The ones available in my local electronic stores have connectors to solder wires, not to solder in a PCB. The other problem was that a toggle switch has a different height that rotary switches so the enclosure fit will be very dificult. I'm already having trouble getting potentionmeters that fit the switches height and that can be soldered in a PCB.
I'm not a purist, in fact I don't care if the layout or components positions are the same as the original, I was just looking for a layout that includes both switches and pots so I can cut off the wiring and I found it. Now if you don't care soldering a couple of extra wires you can replace some rotary switches for toggle ones but I don't think it'll get smaller if you do that.

If it helps you i found a way to use a DPDT instead of a rotary switch in the sweep (up/down) switch.

[Skruffyhound]

I can see the logic, and the price of the rotaries doesn't justify all the work to move the traces. I guess I'll have to just accept that it's a big sprawling effect. It could be half the size, but perhaps it's just not a good idea to cram it all together too tight, maybe it avoids bleed through, ticking, noise, whatever.
I think I have the switching down, but would be interested to see what you came up with.

[jota.ventura]

ringworm: you're right, I thought it was obvious, but maybe not so.
ChanchoPancho: good point, I draw it just after I uploaded the image.
Skruffyhound: the pcb can be drastically reduced if you want, there are not so many components in it and yes, you can use other kind of switching. But even if you ommit the send/return and pedal jacks, still there are 6 potentiometers to fit in. So why worry about space? I just bought a big box.

[ChanchoPancho]

I have some news about my build. In an earlier post i said that I was checking some details. The thing was that the effect seemed to be a little high in every frequency given by the range switch. With the Intensity pot in the minimum, the effect still sounded too high, and in the maximum position, it was so, that in higher ranges I wasn't able to hear it. I checked the the pots and they were OK, also checked the tracks but I couldn't find any errors in the layout nor in the soldering. I thought that changing the voltage near the intensity pot I can lower the frequencies of the filter, so I decided to replace the 1KB Intensity pot for an 5KB. I couldn't find any so I replaced it with the attack pot, which in my opinion wasn't doing much. Now I have:
Attack: 1KB
Intensity: 5KB
Now the effect frequencies are lower and more how I expected them to be. Now I have a little problem with this mod: The green led doesn't turn on in the higher half of the Intensity pot so I will lower its series resistance (R12). I guess it will maybe change the frequency but I'll test it and keep you informed.