DIY project assistance

Thhhh · 2024-10-06T20:08:32.234Z

Probably an easy question, but I have used these potentiometers (PTV09A-4025U-B103) for a diy project. I’m wondering which kind of sleeves to look for. Long T18?

infovore · 2024-10-06T20:27:09.796Z

Those black plastic ones aren’t really designed to have any sleeves on them: they’re trimmers designed to be manipulated directly - think the little black knobs on, say, a Mutable Instruments Stages. T18 will work, I think - it’s how people add knob tops to things like a Moog DFAM (which uses those trimmer pots) but it’s not quite as good a fit as on a genuine T18 pot.

Thhhh · 2024-10-06T21:01:30.306Z

Yeah, I realised after soldering and it feels a bit of a waste to have to swap them now… The bom showed these, but illustration images are with a Mannequins-style sleeve. Perhaps w/a bit of glue?

staysh · 2024-10-07T19:05:06.117Z

Thonk carries a special topper for tall trimmers.

getpunched · 2024-10-23T21:56:33.096Z

Looking for some direction - I’m not a builder at all (other than wiring some basic beginner eurorack modules together). I have an art exhibition proposal I am writing and need a way to randomly distribute audio signal to different speakers. Basically, an audio sample would play through one channel out, and when that signal ended (or dropped below a certain volume) a new audio channel would be selected to play through next. I don’t think stereo would be necessary. In my head it is just a small box that has one input and 4-5 outputs with instrument lines out to the speakers.

I’m sure this is possible, but I don’t know the language or what kind of circuits would be required to ask a builder to think about. Any advice would be appreciated. Gracias and merci.

Shiftr · 2024-10-23T22:14:14.750Z

To me that sounds like something I would set up on a computer and not special hardware. I think you could program this in Qlab or maybe also in Ableton live. Other more advanced options would be Pure Data or Max and probably many more.

And you could look here:

Looking for technical advice on a multichannel audio installation General

This doesn’t seem to be suggested yet but the cHeapest way to do this might be to just get 8 (Or 4 Stereo!) old MP3 players and hook them up to 8 cheap speakers by Bluetooth or by wire. But it depends on how long it needs to run, how secure the installation site is, how synced everything needs to be, etc.

atlas · 2024-10-29T03:28:41.280Z

hi all,

so i’m somewhat naively trying to build a foot pedal to cv interface. my idea was to use a footswitch to carry the signal from a 9v battery to the cv input. when i assemble everything with alligator clips outside the enclosure it works as expected.

but when i put everything in the enclosure it stops working. i understand that this has something to do with the jacks being grounded to the enclosure (because when i assemble everything outside the enclosure but ground it to the enclosure i get the same result). can someone explain to me what is happening here? my rudimentary electronics equipped brain does not understand. also - what should i do? should i just use stereo jacks at the input and output to isolate the grounds from the chassis? use a non metal enclosure?

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widdly · 2024-10-29T05:51:07.002Z

All the grounds connect through the metal case. Each 1/4" socket has a built in connection to the case on the sleeve. The negative of you 9v battery needs to connect to the metal case too, I would do that through the S lug on one of the 1/4" sockets.

In your photo it is hard to see the socket and plug from the expression pedal. They should be TRS ( stereo) not TS (mono). I’d take a good look at your TRS 1/4" to the pedal. Make sure the R is the output, the T is 9v positive from the battery and the S is the ground. I can only see 2 connections in the photo. Here is an example of how 3 wires connect to an expression pedal. Vdd is the 9 volt positive. The point labelled “ADC input” is where your CV output goes.

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infovore · 2024-10-29T11:47:54.284Z

Get everything to the same ground reference: connect the black/0V connection on the battery to a ground lug on a jack.

atlas · 2024-10-29T15:29:22.770Z

if i’m following, then i have everything wired properly. the socket from the pedal is trs, the socket at the output is ts. the issue is that as soon as the two share a ground it stops working (which happens through the enclosure).

here is how i have it wired up. if i connect, say, the points labelled X and Y, it stops working.

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sonoCircuit · 2024-10-29T16:44:01.096Z

I’d wire it up like this:

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positive voltage goes to the ring of the expression jack, tip to tip and both sleeves to gnd.

ciso · 2024-10-30T13:19:18.303Z

Is there anything similar to the Mutable Instruments designed “breadboard friends” out there? I’m wondering what my options are in that respect. I don’t even need it to sit in the breadboard if it has places to connect the jumpers…

bchampion96 · 2024-10-30T13:49:46.518Z

https://www.thonk.co.uk/shop/clacktronics-proto-psu-kit/

https://www.thonk.co.uk/shop/mki-erica-edu-labor-kit/

https://www.kickstarter.com/projects/microrack/microrack-affordable-and-compact-modular-synthesizer?ref=discovery&term=microrack&total_hits=1&category_id=339

These guys come to mind, though not quite the little modules you’re thinking of!

ciso · 2024-10-30T14:00:55.358Z

I apologize, I could have been more clear of my goals. I’m not looking for a PSU, I already have one. I’m mainly looking for pots and jacks that don’t fall out of the breadboard when I accidentally bump into them.

Labor looks awesome but a bit costly and if I were to run out of jacks and pots, then I’m in the same boat.

Jensu · 2024-10-30T17:37:15.150Z

I don’t know where you are based, but if I search for “bread boars friends” on Google, I find two shops in the EU/UK that are selling the boards.

ciso · 2024-10-30T17:42:22.670Z

I don’t have a problem getting the bread board friends, but I’m wondering if there are other options that might make more sense for me.

AndyDavies · 2024-11-10T10:53:13.906Z

Mitch at Hack Modular has these PCBs that help mount pots, sockets, switches etc in a breadboard https://www.tindie.com/products/hackmodular/breadboard-buddies/

A bit fiddly to solder some them but they work fine for me

Jfkimmedy · 2024-11-15T14:12:05.982Z

I’m trying to build a present for a friend (I can solder and follow instructions but I have little understanding how circuits work so I usually stay away from anything besides DIY kits) and he had an idea thats not really practical but I kinda see why it at least could look fun. He wants to replace the potentiometer (in this case the gain knob) with a fixed resistor or more precisely - multiple resistors that can be patched in place so to speak. Kind of like a fake modular where it’s only a circuit that gets closed instead of actually sending something through the wire. So I looked for a simple distortion circuit and since I build the MXR Dist+ Kit from Musikding before, I settled on this.

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Now I tried to implement the “modular” thingy and came up with this:

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Like I said, I have no idea if this could work, but does it look like it might work?? I’m sure there are problems that I don’t even know about.

EDIT: meant resistors not transistors

charbot · 2024-11-15T18:17:07.910Z

Its a little confusing, what you are trying to accomplish, because you mention replacing the pot with transistors, but the second photo show it replaced with multiple jacks. I assume that you want CV to control the distortion/gain, right? If so, you could prob achieve this with some DIY vactrols -LDRs (light dependant resistors) and LEDs. … CV connects and illuminates the LED, which lowers the resistance in the LDR…but since the LDRs only have two legs, you would need to be sure that the gain control is setting the gain of an opamp stage… (potentiometer has center pin and one of the outside connected) and not attenuating the volume ( all three legs are wired to different points). Ideally, you would want to find a LDR with a similar value range as the pot that you are replacing.

Shiftr · 2024-11-16T10:17:10.682Z

Jfkimmedy:

a fixed transistor

I think you mean to say resistor here. Then your story makes sense. And the drawing also. It looks like it would work the way you think but I have no idea why you want this. It adds nothing only takes away possibilities

Jfkimmedy:

a fake modular

If it’s just meant to look cool why don’t you just add lots of jacks and wires without connecting them?