The Passinwind Open Source Preamp

Discussion in 'Pickups & Electronics [BG]' started by Passinwind, Dec 25, 2016.


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  1. Passinwind

    Passinwind I know nothing. Commercial User

    Dec 3, 2003
    Columbia River Gorge, WA.
    Owner/Designer &Toaster Tech Passinwind Electronics
    Do tell. Or_wink.gif

    Here's the offending miscreant:

    PW3BLPF_V2.jpg

    It seems obvious that there's enough board space to allow sitting that resistor down, but for whatever reason it took a lot of dweebing to make that happen without screwing up the ground plane. In v1 that resistor and another one were mounted on the resonance pot, which made it easier to try different values. Originally I had both of them in vertical orientation, then only one, and now none. I also found a good cap option to replace the silver mica one just below the IC on the left. Mica caps are crazy expensive unless you buy them in bulk from surplus jobbers, and physically small ones are just a PITA to source in general. But small C0G ceramics are easy to come by and will likely work just as well in this application. I'll also be trying some easier to find metallized film polypro caps for the filter section, since 8.2nF low voltage polypro film and foil caps are rarely stocked by any of my usual US vendor choices. A couple of matched blue caps would break up the monotonous color scheme anyway. cool.gif
     
    Spacecase, Marial and ctmullins like this.
  2. vbchaos

    vbchaos

    Sep 5, 2011
    Groningen, The Netherlands
    Uncompensated endorsing user: fEARful
    Yes, that does work quite well. Sometimes, not touching the project for a few hours/days even solves problems. "It didn't work yesterday but look how it's running nicely now" :)

    Following this thread with interest! I still try to figure out if I profit from a build. Your 3way preamp does magical things in my Ibanez bass. I wouldn't know if this preamp would do the same or even more.
     
    Passinwind likes this.
  3. Passinwind

    Passinwind I know nothing. Commercial User

    Dec 3, 2003
    Columbia River Gorge, WA.
    Owner/Designer &Toaster Tech Passinwind Electronics
    The one you and Dirk have is now called the PW3B-DLX. The treble section in that design is a good bit more subtle in the control feel, and doesn't do cuts as well as the new one. If you're still playing aggressive/metal stuff I think you'd probably like the LPF one a lot. But it's really down to two flavors of ice cream for your pie, pick your favorite.
     
    vbchaos likes this.
  4. vbchaos

    vbchaos

    Sep 5, 2011
    Groningen, The Netherlands
    Uncompensated endorsing user: fEARful
    Honestly, the treble section is hardly audible on my current pre. The fact that this preamp is so clean and transparent is what makes it so lovely. And of course, the mids :) They do the magic on my bass

    If this new pre has similar options to adjust low and mid frequencies then a build becomes interesting
     
  5. Passinwind

    Passinwind I know nothing. Commercial User

    Dec 3, 2003
    Columbia River Gorge, WA.
    Owner/Designer &Toaster Tech Passinwind Electronics
    The older treble stack has quite a substantial effect if using a really good compression driver, which is exactly how it was meant to be. Yel_wink.gif

    The new preamp has the exact same bass and mid section, except that the feeding stage to it now has lower gain since the LPF is not lossy like the treble stack in yours. So the bass and and mid sections should have even more headroom now.
     
    Marial likes this.
  6. vbchaos

    vbchaos

    Sep 5, 2011
    Groningen, The Netherlands
    Uncompensated endorsing user: fEARful
    OK OK, you got me - I'll build it :)
     
  7. Passinwind

    Passinwind I know nothing. Commercial User

    Dec 3, 2003
    Columbia River Gorge, WA.
    Owner/Designer &Toaster Tech Passinwind Electronics
    You were always going to do that Matthias... Or_wink.gif

    As far as I know, you're still the only other person to have successfully built and installed one of the older ones. A couple of other people have built up nice looking boards and then stalled for whatever reasons though. I'm trying to do a better job on making it easier for people this time around, we'll see how that goes.
     
  8. Matthias, do you have any updated videos of your bass with this pre? I remember the older one, but I think Charlie helped you make a couple changes since then.
     
  9. Doner Designs

    Doner Designs Steve Doner Gold Supporting Member

    Jun 2, 2012
    Metro Chicago Area
    Doner Designs is an alias for Steve Doner
    Awesome. Subbed.
     
  10. Passinwind

    Passinwind I know nothing. Commercial User

    Dec 3, 2003
    Columbia River Gorge, WA.
    Owner/Designer &Toaster Tech Passinwind Electronics
    FWIW, here's an audio clip of my PW3B-DLX:



    For best sound quality be sure to download the Flac. There's a brief clip of the new one on my Soundcloud page too, but the playing is especially craptastic and I didn't really do much control tweaking. I'm hoping to get into my friend's actual studio soon to do a proper one. Nonetheless, here's my Travis Bean fretless with the new one in it:

     
    Last edited: Jan 16, 2017
    jeffmensch and tombowlus like this.
  11. 40Hz

    40Hz Supporting Member

    Awesome! Well played. :laugh::laugh::laugh::roflmao:
     
  12. 40Hz

    40Hz Supporting Member

    Well…now I have all the parts. I'm getting super-chuffed about this pre.

    Probably gonna do it outboard and try it with everything I own first.
     
  13. Passinwind

    Passinwind I know nothing. Commercial User

    Dec 3, 2003
    Columbia River Gorge, WA.
    Owner/Designer &Toaster Tech Passinwind Electronics
    Did you use the Mouser BOM, or...?

    I was considering sharing my stomp box graphics layout too, but I guess we can jump off that bridge if and when we get to it.
     
  14. 40Hz

    40Hz Supporting Member

    The complete Mouser BOM would have been easier. But I already had a little less than half of it in my parts bins, so I ordered a la carte.

    Do you get anything if people use the project BOM? I plan on making more than one of these, so if you get something out of it I'll happily order a full BOM.
     
    Dean N likes this.
  15. Passinwind

    Passinwind I know nothing. Commercial User

    Dec 3, 2003
    Columbia River Gorge, WA.
    Owner/Designer &Toaster Tech Passinwind Electronics
    Nope, I'm not planning on directly profiting monetarily on anything to do with this project as far as the open source side. I probably won't ever order the full BOM myself either, since I already have a big stash of resistors and caps on hand. If you're chomping at the bit to get going PM me and I'll let you beta test the new board layout if you like. That would help keep things moving along, since I won't be able to get to doing any more builds for at least a few weeks.
     
  16. 40Hz

    40Hz Supporting Member

    Your call. If it would help you out, I'm definitely in. PM me and we'll make the arrangements. If you're doing it just for me, I can wait. You've already done enough for this community as it is. :)
     
  17. Passinwind

    Passinwind I know nothing. Commercial User

    Dec 3, 2003
    Columbia River Gorge, WA.
    Owner/Designer &Toaster Tech Passinwind Electronics
    Cool, I'll PM you then. The sooner a few experienced builders start chipping in on some of the work, the better.
     
  18. Hey, Charlie, can you post pictures of the graphics? That could possibly give an idea of knob layout and configuration for instrument implementation, at least number of knobs if anything else.
     
  19. Passinwind

    Passinwind I know nothing. Commercial User

    Dec 3, 2003
    Columbia River Gorge, WA.
    Owner/Designer &Toaster Tech Passinwind Electronics
    Sure thing Mark. Here's my first test box, using a 4S1590BBM enclosure from Mammoth Electronics, with a simple DIY laminate overlay printed on my inkjet:

    LPFStomp_WK.jpg

    And then the two UV printed 125BB ones I got from Pedal Parts Plus, in two very different shades of purple:

    PW3B_LPFstomp_NAMM.jpg

    All three have a 3-way mid shift switch and I've tried mids set at anywhere from 400Hz to 2.6K with the older preamp. Possible alt configs include a 2 or 3 way resonance switch instead of a pot (switch could be on a pull pot too), omitting the mid control completely and/or using a switch for mid contour. I've been using Vol-Vol in front of the preamp, but Blend in front and a Master after the preamp should work fine too.
     
  20. Is the switch for the mid control center freq.? If so, what are the values?
     
  21. Primary

    Primary TB Assistant

    Here are some related products that TB members are talking about. Clicking on a product will take you to TB’s partner, Primary, where you can find links to TB discussions about these products.

     
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