Passinwind Open Source Hybrid Filter Preamp Builds

[cwsquared]

Cool, the new one uses those same boards too. So you can add either or both other modules if and when you feel like it. I already have HPFs built into all my bass amps anyway and don’t necessarily need the variable gain stage, but those features are very important to two actual paying customers, hence the bigger enclosure. Plus, I really don’t like to do the exact same thing twice!

I like modularity, especially in this case.

 

[Passinwind]

Newest version up and running. It absolutely killed on my friend's upright bass the other night, although this particular one isn't even optimized for that application.

 

[Passinwind]

New v2 125B board in the works, the first real open source contribution to my project that I didn't have to do myself:



This one uses all Tayda parts and there are no SMDs. The designer has already ordered a set of boards from JLCPCB, so hopefully it will go live within the next month or so. And then I'm going to hand off a schematic or two to Robert and let him take things wherever he feels like, because why not?

 

[Passinwind]

Latest version of the Baxandall based Bass/Mids EQ module:



And the latest resonant filter module now has gain leveling and polarity swapping built in, so the overall build will finally be non-inverting. Gain range is tunable, my first testers are set up for -10 to +6dB with unity gain at noon.

 

[Passinwind]

Family photo of my four WTHPF builds, the one on the right is the Peacock Ore finish and for that build I optimized a few more aspects for upright bass:



The new gain leveler circuit configuration seems to be working really well, so I can can probably go back to something smaller than the 1590BBS now if I build any more of these.

 

[Passinwind]

Here's the URB one with the actual hardware it's going out to the new owner with:



We took it out to an open mic on Sunday night and it kicked butt, even through a little Peavey 1 x 8 practice amp. Time to build one for myself!

 

[Feral Feline]

What, no gut shot?

 

[Passinwind]

What, no gut shot?

Ignore the junk behind the curtain...

Too scary, and mostly all you could see would be the little Nomex origami boxes I wrap the modules in before I stuff everything into that enclosure. Starting the next build today or tomorrow, the last of this series. Then I'll get to work on some much tidier solutions with all three of the current modules on one board, way less offboard wiring, etc. But the modular approach I've been using has been super useful during the R&D phase.

 

[Feral Feline]

I dig modular.

 

[Passinwind]

Here's a project contributor's new build, using a fiberglass fascia plate made by JLCPCB:



Everything sourced from JLC or Tayda, and he did his own board layout which he has kindly shared. Just waiting on his final testing before we take it live. This is his second go-round, same guy I mentioned a little upthread.

And then I'm about to truck on down to the post office to pick up a couple of these new enclosures that Amplifyfun just did for me:



Having Spencer drill all the holes is so so worth it! This version is always-on, has side jacks, and is meant for desktop usage rather than being a floor pedal.

 

[Passinwind]

My version of the first one in post #30:



Tayda drill and print job, which took a bit longer than usual but came out fine. This particular build especially shines on acoustic guitar, with either piezo and magnetic pickups.

Most recent WTHPF (v4) builds:



v2 needs one more board revision, so live launch is probably about 3-4 weeks out.