90phase

[wgc]

I had a friend ask me to build him a phase 90.   

We go back about 30 years, sounded like fun, no deadline, so I used it as an opportunity to do an SMD layout for 1590a. 







I remembered a post regarding the jfet dual packages and put them to use here. 
http://www.madbeanpedals.com/forum/index.php?topic=13182.15

FYI I did no matching, pulled them out of the strip and soldered them in.  A lower trimmer value might be worth trying.  Anyway, it worked out great!  That said, YMMV.

I could probably do a bit more on the layout and route things in a way that is a bit cleaner, but I don't mind vias too much as long as the traces don't get too crazy. 

I could probably come up with a more efficient top/bottom side parts approach too, but hey, I've got things to do and people to see.   

Oh yeah, the other thing is I had a scary moment when I first tried to fire it up.  It didn't work, powered up but no sound unless bypassed, and crazy dim led.  Much head scratching ensued, I started to ohm things out, and then realized my mistake...  I turned the 3PDT 90 deg when I was working on the layout.  Seemed like a good idea at the time, except I completely forgot that I did so when I soldered in the switch.   

Much swearing and sweating later, I turned the switch, soldered it in, and swooshy goodness came out right away.  Yes, I am truly blessed, but I tweaked the trim pot anyway. 

Powdercoat and graphics by me, powder is granny smith dormant green, laser etched and back filled with black acrylic paint.

Building the second one for my friend very soon.

[pickdropper]

Coooooool.

[wgc]

Thanks Dave!  You've been a big inspiration...!

[pickdropper]

Thanks Dave!  You've been a big inspiration...!

If I've played any part in inspiring the work you've been showing off, I take that as a huge compliment.

[wgc]

Huge inspiration, mega huge compliments to you. 

BTW I will be posting my builds of your pcbs soon, way overdue.

[GrindCustoms]

That got lots of awesomeness content, great work!

So if i understand correctly what you are saying about the SMT dual pack JFET, chances are that the each individual packaging are a matched set?

[pickdropper]

That got lots of awesomeness content, great work!

So if i understand correctly what you are saying about the SMT dual pack JFET, chances are that the each individual packaging are a matched set?

That hasn't been the case of the single package FETs I've seen, but maybe the duals are different. 

It doesn't surprise me that both FETs within the package match well.  I'm really surprised that you can randomly grab two duals and have them match.

[GrindCustoms]

That got lots of awesomeness content, great work!

So if i understand correctly what you are saying about the SMT dual pack JFET, chances are that the each individual packaging are a matched set?

That hasn't been the case of the single package FETs I've seen, but maybe the duals are different. 

It doesn't surprise me that both FETs within the package match well.  I'm really surprised that you can randomly grab two duals and have them match.

Agreed about grabbing 2 packs and have them matching, but for phase45... this makes it quite awesome!

[chuckbuick]

That looks great, Billy.  All around.  The board mounted 3PDT is a nice time saver, too.  What size are D1 and D2?

[jubal81]

This is just outstanding on several levels. I'm blown away.

Any chance we can hear it in action?

[selfdestroyer]

I love that color and the laser etch looks so awesome. Can I ask how you applied the black acrylic? Did you wipe it on or brush it? I am trying to get the same results with some etched enclosures.

Cody

[wgc]

Thx guys!  Really fun build, except the switch part.

Mark, I think I used mini melfs but with 1206 pads. I can check later.

Cody, I just wipe it on, let it dry a little bit past tacky, and then I use a damp cloth to clean the parts I don't want to have fill.  The hard part is keeping paint in large flat sections, since it can wipe out easily while cleaning up the other areas.  Which is why I added some noise/texture here to the graphic before lasering.  Also, I use a tube of pro artist acrylic, not the hobby style that you get for a buck.  I think the pro stuff is about $5 but it will last a long time. Don't worry too much about getting the excess off if it dries too much, you can still do it but it takes a little more effort.

[selfdestroyer]

Cody, I just wipe it on, let it dry a little bit past tacky, and then I use a damp cloth to clean the parts I don't want to have fill.  The hard part is keeping paint in large flat sections, since it can wipe out easily while cleaning up the other areas.  Which is why I added some noise/texture here to the graphic before lasering.  Also, I use a tube of pro artist acrylic, not the hobby style that you get for a buck.  I think the pro stuff is about $5 but it will last a long time. Don't worry too much about getting the excess off if it dries too much, you can still do it but it takes a little more effort.

Thanks for taking the time to explain your process. I will definitely give this a try.

Cody

[Leevibe]

Wow. I'm blown away by every aspect of that build. Great work in and out!

[wgc]

Thx Lee!

My pleasure Cody. I've been thinking of trying a squeegee to use while the paint is wet, just need a squeegee...