Build Shit - DIY - What's On Your Bench?

[FAP]

Alright, this will be the last 'big one' for the year, possibly for a while:

Another circuit-bent white noise machine, though one of the higher end models from what I've seen: you can't visit any thrift store around my neck of the woods without spotting at least one of those Homedics Sound Spas amongst the detritus, but I've only ever come across two of these things in the wild. Or I could be full of shit.

Ten stock sounds with three modes (single/combine/random), two volume buttons, on/off/timer switch and a headphone jack (mono, though surprisingly plays in both channels simultaneously) make up the native functionality.

Here's what I added:

Adjustable PITCH [of the stock sounds] pot with range select and optional external LFO interface; the FAST range goes from roughly 1.0x to 2.0x as fast, while the SLOW range can go from about 3.0x to 1.0x as slow.
Adjustable FEEDBACK pot with on/off toggle, contacts, and optional external LFO interface. The feedback comes from a native LM386 chip: I'm still adjusting this at time of writing, as not only can the chip 'lock up' if the resistance between its input & output is too small, the threshold of the resistance also appears to be dependent on what the output is ultimately driving (either the native speaker or the added 1/4" jack). I'm apparently the first [noise] dude to try running a feedback loop with an LM386 so further research is required...
Adjustable GAIN (from the LM386) and COARSE and FINE DISTORTION pots.
Five different adjustable SPUTTER pots, all with optional external LFO interfaces. These basically chop up the output signal by rapidly resetting the unit at a variable rate(s); they all sound similar to but just different enough from each other to produce a rich spectrum of hard cuts and dying drones. I'll also be modifying this slightly in the future as the aforementioned 'drones' are rather unimpressive IMO, but hey, maybe that's right up your alley
A switched 1/4" jack: this is different from the native 1/8" phone jack, as it draws from the amplified signal normally meant for the speaker, whereas the 1/8" jack is assumedly line level.
An optional LOAD TOGGLE switch. When activated, this places a 3.9Ω resistor across the + & - of the 1/4" jack: this was done in an attempt to emulate the typically expected 4Ω load of the speaker, though in practice it acts more like a hi-pass filter for the 1/4" jack.
Switched 9v center-negative power jack/9v battery option.

This one's actually a 'remake' of an earlier build from 2020. I could've sworn I had posted it here before but that doesn't appear to be the case. I did take a comparison photo (old one on the left) so you can see the old one here regardless:

The ever-classic "bitches love my switches" sticker was not present on the new model when I took this photo: this grievous error has since been rectified.

As you can see, I used a VHS case back then as well, which I would not recommend. If I come across another one of these things, I'm creating a new enclosure from scratch, because trying to take advantage of as much native enclosure space as possible—technically two enclosure spaces combined together—ended up being less savvy and more inconvenient. In the image below, you can see an example of how I tried to maximize space by mounting a piece of vero/perf board in the space formerly occupied by a battery compartment (in the absence of 4x AA's, the stock unit uses a linear voltage regulator to drop the 9v coming from the wall wart down to 6v). White this idea is cute in hindsight, it simply added another layer of bullshit to manage on top of the four native PCBs' wiring, the native enclosure components' wiring, and the VHS enclosure components' wiring.

Having since worked on much, much larger enclosures with plentiful space and adhesive tie-downs at my day job, my days of optimizing obtuse prefabricated shells are coming to a swift end. A larger, custom enclosure would also alleviate the other major headache with this project: the stock buttons have a tendency to stick, 'locking' a sound into place if pressed the wrong way. Holding down one of the ten sound buttons prevents any other button from being pressed; this includes the 'mode' button which, as you might imagine, convinced me I'd somehow 'crashed' the entire unit. Turning the unit on and off again didn't resolve the issue: this is obvious in hindsight, but I was driving myself nuts trying to find the right combination of factors that triggered this mysterious issue ("maybe if I turn on gain AND three of the sputters, but NOT either of the distortions?") only to find out the root cause was something much more mundane. I'm still investigating possible fixes for this issue ,so if anyone has any bright ideas I'm all ears.

I could go on but I've already spent the better part of an hour writing this all up. I certainly learned a lot.

Happy Halloween, everyone!

[crochambeau]

Nice work!

Regarding the sticky buttons, that could just be a side effect of the injection molded plastic design. Could be a need for chamfering an edge or cutting sprue or flash on the button cap - or it could be that the "pocket" the button cap rides in is overlarge and needs some guides or also has some flash or sprue that is acting like a catch. You'd have to dig into it to see what's what. PITA, I know.

[FAP]

Could be a need for chamfering an edge or cutting sprue or flash on the button cap - or it could be that the "pocket" the button cap rides in is overlarge and needs some guides or also has some flash or sprue that is acting like a catch.

I swear, every time you reply to a post I made, my vocabulary expands by at least a couple of new words

Your recommendation for adding guides intrigues me, because my initial plan was sort of leaning towards the opposite.
Pic related: bit of a weird composite shot but you should get the idea.
All the buttons are connected on one side [or another] by these big light blue sprues (I hope I'm using the term correctly): my thought was, if I cut the buttons from the sprues (cut marks in red) the buttons wouldn't be inclined to lean a particular direction and, in theory, wouldn't then be inclined to get stuck in a particular direction.
This would mean the buttons would all be loose now, sure, but at least they'd be free to wiggle around some more.
What do you think?

[crochambeau]

It's difficult to know if that will make your issue better or worse, but I'd bet you can find a way to fix it if cutting those parts winds up biting you in the ass.

I did a stint in a plastics injection molding factory in my early 20s, sprue is typically a waste product, the channel to allow material into the molds. We would manually snip them off, but it was often imperfect.. I don't miss that place at all. From the button's perspective, those are essentially sprue (but I think technically it would be called something else related to the finished object, as they look very intentional).

Good luck!

[crochambeau]

I have found the rolls of foam tape (like weather stripping) very useful when coercing stupid plastic parts that don't want to move like they should. It's kind of springy without conducting electricity and can fill voids where you don't want the part to go..

[Indeterminacy]

I can't help but think of how excellent your mods/build would look in a modular
Euro-type rack.

[FAP]

I can't help but think of how excellent your mods/build would look in a modular
Euro-type rack.

I’ve definitely flirted with the idea, but retrofitting it all would be a Herculean task. Plus I like being able to do shows without needing a pickup truck to haul my own gear *cough*crochambeau*cough* still, it’s not entirely off the table.

[crochambeau]

Plus I like being able to do shows without needing a pickup truck to haul my own gear *cough*crochambeau*cough* still, it’s not entirely off the table.

I've played shows recently the involve me walking into venue carrying everything I will use in one trip with two arms.

I mean, it's heavy, but I don't need (or have access to) a truck or a van.

[FAP]

Plus I like being able to do shows without needing a pickup truck to haul my own gear *cough*crochambeau*cough* still, it’s not entirely off the table.

I mean, it's heavy, but I don't need (or have access to) a truck or a van.

Huh, I could’ve sworn you had mentioned once bringing like a 6ft. tall rack mount thing for a show. Current setup looks nice btw.

[crochambeau]

Plus I like being able to do shows without needing a pickup truck to haul my own gear *cough*crochambeau*cough* still, it’s not entirely off the table.

I mean, it's heavy, but I don't need (or have access to) a truck or a van.

Huh, I could’ve sworn you had mentioned once bringing like a 6ft. tall rack mount thing for a show.

My show racks topped out at around 3-4 feet, but I have used three of them at once. Been years, I don't gig tubes any more, for the most part.

So yeah, 100% I have been in the position of needing heavy haulage for shows, but sometimes consolidating a bunch of shit in one place (like modular) serves to reduce your footprint.

Current setup looks nice btw.

Thanks! It's usually wired up so I can just drop the lid on it and lug it somewhere, plug in and away we go. I needed to look at the build that is guts up in the pic, so all wiring is pulled (I think it's more visually appealing when wired up).