my WTPA 1.0 finally done!!!
hey guys! i'm building my 2nd party, a WTPA 1.0 of course and have just soldered the SRAM. i've tested connectivity between pins & copper traces, also checked for bridges with a magnifying glass.
the thing is, i'm not too confident about my smd skills (as always) and would like to ask if there's a way to test the sram right now whether it's fried or not rather than waiting until i have finished the whole thing.
is that possible?
edit: typos
edit: changed the name as i'm posting progress to the thread


  • That looks pretty good from here. If the other side is the same, then I think you are good to go. I'd just plod on with the rest of the build :)
    Even if you could test it, it wouldn't take much longer to just finish it off anyways. Plus I expect you'd need a good scope..
  • thank you. i've already put in all parts except for the 118K and the 20p in the meantime, i figured i could swap it on a stuffed board as well in case it should really turn out fried.
    the joints seem ok. but i had to heat it up quite a lot doing the solder wick job. hope it's still alive. but anyway, i guess having a party is the easiest way to test it.
  • Todd has provided a good description of soldering an smd however here's a 6 min video on soldering a smd chip. A different technique. More choices that's the ticket
  • @rosch--
    Those connections look beautiful from that pic. I've sold joints that look far worse. If you're that close to done, I agree -- just finish the build and test that way!
    The method of soldering in that video is not so different than mine, just a lot cleaner :-)
    I tend to use a flux pen and a lot of solder and then PLAN on removing bridges. His is probably a classier way.
  • edited June 2010
    yeah that guy does a clean job, compared to me. here one whole side of the sram was one large bridge.
    when soldering the next chip i'll make sure
    - i have flux, which i've never used, always forgot when doing orders.
    - i don't lay a whole wire of solder along one side of the chip, the method in this video seems much better.
    - to position the chip correctly in the middle of the silkscreen
    seeing how little heat's involved in this guy's soldering i can only pray that mine will work!
    but i'll have to wait a few days for the 118k and 20p which i had to get from ebay (U.S.)
  • I like the header idea for the LED/pot/buttons.
  • Kickass! Good work. I like that header idea too. So much, in fact....

    that's my frontpanel layout i just sent to the guy who's doing the repro... so maybe tonight i'll be able to drill the holes.
    i'm going to use alucorex, black on natural aluminum.
    i hope the scales match the size of the knobs... anyway, it's too late to make changes now.
  • edited August 2010
    crap- i forgot the OUT OF RAM LED
    i knew it

    edit: power LED too
    i knew it

    oh well it's friday 13!! i should have known that!
  • Don't see the usefulness of the out of ram LED as you'll know you're out of ram when it stops recording.

    Either way, that lookings fucking badass. I labelled mine similarly, and by similarly I mean, the marks above the knobs for combined presses, and with pencil. So not similarly at all!

    I look forward to seeing it done.
  • yeah you're right. probably i won't need it. also the power LED.

    i'll expose it tomorrow, the repro is already done. then i'll also see whether the lines in the scales are ok or too small.
    so with a bit of luck i'll be able to show first results tomorrow evening!
  • edited August 2010
    so, on top of forgetting the leds the scales turned out to
    1. have too narrow lines which resulted in being removed during the developing.
    2. be too small anyway, look at the tiny numbers around the knob!

    so, i'll do a new layout until tomorrow, with just dotted scales without numbers, but a bit bigger, add the missing LEDs this time and also enlarge the font size of the fX description, it could be bigger. maybe i also rearrange the whole thing a bit (eg leaving a bit more space for the mounting holes, mark every hole as such instead of the too easily etchable scale markings.
    and i also learned that 1.5mm thick aluminum is indeed thick enough and won't bend at all (that was a concern too). i could even make bigger sizes without worrying about that.
    that's learning. on monday we'll do the second try (the alucorex panels are coated on both sides, so i can use the same panel once again)
    but apart from my mistakes this is a nice method in my opinion. i hope i can show a nice result on monday, maybe i should post the next layout tomorrow to receive some criticism (BEFORE it's too late)?

    pics so far:

    and maybe add biggie, duh!

    this should work now ...tomorrow
  • Looks good.

    The placement of the power/mem LEDs looks weird as it doesn't seem relevant to what's going on there. Maybe both top left just before the W in the WTPA or something?

    Also, not sure if it's just the reduced version, but to the right of "window" the lines meet weird.

    Amazing work! Can't wait to see it finished.
  • edited August 2010
    thank you for checking, Rodrigo!! i'm glad you've seen the mistake!
    i've changed it to the original 'out of ram'
  • That looks the business!
  • edited August 2010
  • She's a beauty! I really like those arcade buttons. I'll have to consider them for my final version. At my age, I need all the help I can get to hit those damn things ;>)

    Well done!
  • thanks!
    i like those big buttons too and i'm quite happy with the design, although there are a few drawbacks due to lack of experience:
    - the black rings around the upper leds are smaller than i expected (or hoped).
    - the 5mm leds are not very low profile and i had some trouble fixing them with hot glue, which was no poblem with the Shruti panel in natural aluminum. probably i'll change to using led sockets, just for 5mm types (that would solve both issues)
    - the holes for the arcade buttons aren't centered acurately. that's a real bummer, as one can see it easily because of the black circles. part of the problem _might_ be a small length of straight metal in the arc (and then in different places each hole) that have to be filed down. but the main issue here is definitely my unexact centre punch work :-(
    - another thing i _could_ have noticed if i just had thought about it (like the upper led circles) is that the scales are designed for pots with a travel of 270°, while i use some 300° ones, so the knob marking exceeds the scale dots hehehe

    fortunately this won't be the last WTPA, so i can correct the flaws next time and do better punching.
    but UNfortunately i think i can brace myself for finding more mistakes when it comes to putting this in an enclosure, which is the next step!
  • damn it, why cant we have Alucorex in the US :(

    Looks sharp..
  • Nice work Rosch!
  • thanks guys, i'm glad you like it!
  • edited August 2010
    Wow! That is nice, Rosch. I put mine on the back burner for my ASM2, which is now on the back burner for an album I had on the back burner for a while. This gives me sooo many ideas though.
  • Rosch, this is too good! What a great design. I love how the button combinations are indicated by the lines above the buttons...and those buttons!
    As a hardcore fighting game fan, I have built many of my own arcade sticks, so I recognize those buttons. I have a pretty large cache of them somewhere...
    Great ideas, excellent work!
  • Speaking of the it going to be custom as well?
  • edited August 2010
    thank you very much!
    those buttons are from x-arcade. they were the first i tried on my search for panel mount buttons below $10 and i'm happy with them.

    the enclosure will be wooden, actually thick wooden cheeks left & right and i'll try to get the frontplate a bit beveled, not too horizontal. i'll have to handcraft the angle on the wood, that's what's procrastinating a bit now but i figured out an easy way to do it (i hope). and i'm wondering whether i should add a matching printed back panel too (probably i should).

    also, i crimped my cables to connect the parts 1:1 as if they're onboard, which is actually cable overkill (ground loops also?) as e.g. for the switches and leds i'd need only one ground connection if i strap wire them on the panel.
    i've also received the last missing pots now, so i think there will be some more pics soon. and i hope there will be sound too of course :D
  • Way ta suit 'er up Rosch!
    Aesthetic= great.Front panel layout=great.
    Black pinball/arcade buttons w/those knobs=great.
  • hey Tofino waves! I know what that name means. I'm in Victoria hanging out with moron's noise crowd, though i xoxbox and analog as well.
  • @sealion:
    Yup, winnerwinnerchickendinner-Born in Vic. and making music in Van. presently
    though I REALLY would like to be making music 'portably' on the beach near beautiful Tofino.
    moron=noise festival? I know of a certain Lorne H. in Victoria among others. Gettin up with
    the analog synthesis!
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