Cave Dweller Dub- Picture log and a couple questions?

[davent]

Hello, I've done me Brian's Cave Dweller, Dub version.

For drilling ease, i like 20mil holes in all the pads i use for my layouts in ExpressPCB so when i use someone else's art i open it in Inkscape and change the pads. With Brian's you just drop a new pad with the desired chararcteristics onto the already present pads and you're good to go. Once etched the very small dimple in the center of the pad acts to self center the drill bit, need all the cheats i can get to get satisfactory drill results. Also dropped on fatter traces to maybe speed up etching and save on etchant, at least that's the theory.  Photoresist pcb.

http://www.madbeanpedals.com/projects/CaveDweller/CaveDweller.pdf

My Issues
In this incarnation mine's pretty noisy as well as being below unity gain. Have dropped the input cap to 47n but lacked lower value resistors to try in R1 as well as values to play with the voltage divider on the output to see if i could increase the output volume. Used BC549c's. Have a Rebote in the works that will allow easy auditioning and sorting of PT2399's to see if that will help with my noise. Any other suggestions for lessening noise and greater volume output are welcome. Anything else i may have screwed up? 

Cave Dweller and Rebotes.

Nitty Gritty
Used Inkscape to layout the labelling and create stencils instead of going all random-exploration on this enclosure.

Stuff used, frisket film and liquid frisket, razor knife/scalpel.

Acrylic mediums all from Golden;GAC200, Airbrush Medium, Self-Leveling Gel and Acrylic Grounds for Pastel.

Paint; self etching primer, BIN Shellac Based Primer Sealer, Auto-Air White Base Sealer, Paynes Grey and Aquamarine Blue Fluid Acrylics from Golden.

Printed out first stencil, covered the art with a piece of frisket film then lay on another piece of film, this one will be the stencil, the first sheet just protects your stencil from getting contaminated with paper fibers and losing it's tack.

Once it's cut out apply stencil to enclosure and give it a couple coats of GAC200/Airbrush medium to seal in the edges and prevent paint seaping under the frisket. (If you wanted to apply the cutout pieces to your enclosure and paint around them, you'd use a third piece of frisket film to lift them out of the second sheet and transfer them to the enclosure.) To register the stencils to the enclosure i just draw on the stencil where the switch and pot holes are and use those to line up the stencil with the enclosure

The only way i could get ok results was by masking off and painting one section at a time.

At this point sprayed on a couple coats of GAC200/Airbrush medium, let it dry, then went back at it with sandpaper to fix up the fade.

Second stencil, again two layers of frisket, just cut out the letter outlines then used tape to create the islands within the outlines.  Had to use liquid frisket to touch up the ragged cutting of the film then sprayed with the GAC mix before colouring.

Toner transfer for the jack labelling. Cut out the jack hole in the transfer, use that to line up the label to the enclosure, tape one edge of the transfer to the enclosure so there's a hinge that will allow quick and accurate repositioning of the label after applying medium (GAC200) to the enclosure.

Clearcoated with Target 7000 waterbased, waterclear spraying lacquer.

Using a Geofex "Cheap Polarity Protection" circuit on a daughter board.

cheers, dave

[jimilee]

Really nice man,and very tedious. Good for you really taking your time and enjoying it. Did you get the bugs worked out yet? Cavedweller is still my favorite delay.

[midwayfair]

Always enjoy seeing your process, Dave. Wish I had a good way to help with the unity volume problem.

tedious

O_o
I think you mean "meticulous."

[jimilee]

Always enjoy seeing your process, Dave. Wish I had a good way to help with the unity volume problem.

tedious

O_o
I think you mean "meticulous."

That too! :-p

[nzCdog]

Awesome build man, and thanks for sharing your cool ideas on finishing... looks teh binnis!

[lincolnic]

Thanks for sharing your finishing process with us. I'm not at all good at that kind of thing, so it's a pleasure to see it actually come together.

[rullywowr]

I really like your methodical approach to setting up a test jig to wire everything up before putting it in the pedal.  makes for a nice and tidy build.  As long as you get your drill holes right and measurements, you are good to go.  Great work!

[davent]

I really like your methodical approach to setting up a test jig to wire everything up before putting it in the pedal.  makes for a nice and tidy build.  As long as you get your drill holes right and measurements, you are good to go.  Great work!

Thanks, pretty easy to do, idea's from Geofex and John Lyons.

I create a enclosure drilling template using a CAD program and print off one copy for the enclosure and one for the assembly jig (scrap of very thin plywood, box-board, whatever's handy). As long as the drilling is accurate should be no problems.





dave

[juansolo]

I love the way you do things. Spectacular and original results every time. Truly an artist 

[fendman]

Really nice fella, I like your artwork its class. I  was googling how to alter pcb pads. and traces..and saw your method in Inscape. I am still no wiser   I am trying to get my head round it...but find it difficult.

Great work

Mike

[davent]

Thanks for the compliments guys!

Really nice fella, I like your artwork its class. I  was googling how to alter pcb pads. and traces..and saw your method in Inscape. I am still no wiser   I am trying to get my head round it...but find it difficult.

Great work

Mike

Hi Mike, For pad adjustment i use pads that were drawn first using ExpressPCB, printed to a PDF and finally opened in Inkscape. The pad was drawn as a 75mil pad with a 20mil hole (which would be a plated through hole if you sent the art out to ExpressPCB to be fabbed) so the hole actually measures as 25mil when you open it in Inkscape... not a problem.

I'll attach a PDF i created with pads for a GEOFEX pdf i re-padded.

Take the PCB pdf you want to alter, open the pdf in Inkscape, ungrouped it and save it as an .svg file.

For the workpage create a 0.10 x 0.10 inch grid. Place the pcb art so the center of the pads are centered on a grid intersection, most will lineup perfectly.

You can't alter a Madbean pdf but you can draw overtop of it. (Tonepad's you have free reign.)

Next Import the GEOFEX pads pdf, park it off to the side out of the way and ungroup. You'll find each pad is made up of a 25mil white dot on top of a larger black dot. Group a 75mil pad with it's hole (white dot). Once grouped high-lite it and copy- Control 'c'.

Place the cursor at the center of one of the pads you're re-padding and hit Control 'v', the new pad should be positioned perfectly centered over the old pad. Move to the next pad, center cursor-Control 'v'... etc.

For drawing new traces i set the ink width to 40mil and just trace over top of the thinner traces. Holding down Control as you draw will ensure 90° or 45° angles for your new traces.

Hope that sheds a bit light...
dave