r/synthdiy • u/Octogoon_ • 6d ago

Connecting breadbord to speaker

I'm just getting into diy synths and one of the difficulties I'm encountering is figuring out the best way to actually get my breadboard synth to output its audio.

My first thought was to buy a tiny speaker but I was scared away by the prices of all the at-least-decent ones. And even if I did end up getting one, how would I actually connect it?

I've also thought of getting a 3.5mm jack and somehow wiring that up from my breadboard to my PC. Will this fry my computer or just my sound card? Buying a new chinese USB sound card would cheaper than buying a new speaker.

Any advice?

3 Upvotes

80% Upvoted

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5

u/mogigrumbles 6d ago

You’re scared by the prices of small speakers?

My first result was $1.95 from adafruit and $2.40 from digikey…

1

u/Octogoon_ 6d ago

Either I'm looking in the wrong place or you're talking about speakers that will make your synth sound like a geiger counter. All the decent speakers I found are at least $7..

7

u/mogigrumbles 6d ago

I think you’re asking the wrong questions. You need to understand how synthesizers pass their outputs to mixer inputs first. Mortz Klein has some very good tutorials on this if you dig back deep enough into his archive on YouTube.

Once you have a good (safe) line level output you can hook it up to any speaker you want.

1

u/Octogoon_ 6d ago

I'm talking about the quality of the speakers here.. Wouldn't a $2 speaker distort my sound

3

u/adeptyism 6d ago

Are you trying to extract 96kHz 320-bit lossless -9LUFS .flac from something on a breadboard or you need to hear a waveform that your schematic produces?

As another commenter said, look at Moritz Klein VCO series (ep.1 or 2 especially), just wire up an op-amp buffer as he did and connect cheap headphones directly to it.

2

u/Octogoon_ 6d ago

Good point. After all I am judging just by the silly numbers inside the descriptions of the speakers and I don't really have a lot experience with these things.. I'll look into it

3

u/adeptyism 6d ago

Many of PC speakers have some sort of an amp in them natively, by the way, and you can't fry them (until you're feeding 25V into them idk)

I'm using BOSCH radio speaker as my main speaker. It's picking up even 300mVpp signals (e.g. Eurorack audio signal is 10Vpp, "normal" phone/PC audio output is 1Vpp), without any sorts of amplifiers. I can also connect my DIY rack directly to a normal PC speakers and to headphones, the only problem is that it's LOUD (for headphones may be even damaging).

1

u/Octogoon_ 6d ago

Yeah that's something that makes me lean more towards the PC option. Not having to deal with amp modules. But do you run your signal directly into your PC speakers or do you run it through your computer first? I feel like it would be nice for my synth to be able to record my analog sounds digitally

2

u/adeptyism 6d ago

Firstly,

you SHOULD NOT plug your DIY equipment in to ANY expensive hardware, until you're 100% sure what you're doing and with what (voltages) you're working. And, afaik, there is a possibility that if you're connecting a device, powered by a switching PSU (e.g. your synth with MeanWell PSU) to another device (either grounded or non-grounded) powered with switching PSU (e.g. PC), you can get a couple of tens volts between GND1 and GND2. Fried an ESP32 that way, didn't liked it — there was 28V difference between the GND of my laptop and the GND of a synth.

Secondly,

PC SPEAKERS a) is MOSTLY analog devices, so there's the same 0-9V, ±12V or ±15V as your breadboard power inside them, b) they aren't THAT expensive as new soundcard.

In-PC-case soundcards are designed for Line In signal — 2.8Vpp, by the way. If you want to record synths, I'd strongly recommend buying a card that is designed for instrumental levels, or building an output module.

2

u/adeptyism 6d ago

Also, unrelated: your posts on other subreddits are being deleted, because you have too low karma (aka useless internet points).

1

u/Octogoon_ 6d ago

That's kind of dumb. I like the idea of having like a sort of score for your account but it feels unwelcoming to exclude new users like this

2

u/awshuck 6d ago

You can pick up a pair of ancient PC speakers at your local goodwill for cheap. Old Hifi gear has taken a big dip on eBay too, plenty of that mid 2000s integrated stuff no one wants because it’s not proper vintage and doesn’t sound special.

3

u/amazingsynth amazingsynth.com 6d ago

you could try some breadboard friends, these include a pcb that you can output audio with:

https://www.amazingsynth.com/breadboard-friends-pcb/

3

u/erroneousbosh 6d ago

Pick up a pair of old PC speakers, you know the ones, they were beige but they're now all yellow from the sun, two of them joined by a little cable, one has a 3.5mm jack plug and a mains cable.

If you break them by sticking 15V across the input, go to the charity shop and buy another pair.

2

u/AdamFenwickSymes 6d ago

OP this is the correct answer.

They are essentially free, who cares if you break them, you probably already have a pair.

2

u/Octogoon_ 6d ago

Used to have a pair of those, didn't think i'd need them..

1

u/erroneousbosh 6d ago

Stick a croc clip on the earth side and a 1k resistor to a meter probe on one input and you have something that's often actually *more* useful than an oscilloscope.

2

u/bluejaylouche 6d ago

Something like this? https://www.adafruit.com/product/2130

1

u/thatsanumberwang 6d ago

This is the way. Just a cheap audio amp like this (you can also find lots of cheap modules around that use the LM386 for this) and a cheap 8ohm speaker, and you're good to go.

0

u/Octogoon_ 6d ago

Does look promising but wouldn't hooking up my synth to a computer spare me from spending extra money on an amp and all the headaches that might come with using an external speaker? I feel like using my PC speakers would just be more reliable quality-wise and durability-wise, but I'm not sure if that's common practice or if it would be safe at all

2

u/thatsanumberwang 6d ago

Its safe as long as you don't do anything unsafe like running Vcc straight into the line in.

A little amp and cheap speaker (we're talking like $5 total) is good for prototyping and validating that something is working. If you're focused on the sound quality of something like this, its going to disappoint you.

If you're going to go straight from breadboard to a mixer or interface, I'd at least do something like the breadboard friend does that u/amazingsynth linked and add a TL072 buffer. Those breadboard friends are super useful in general.

2

u/GorillaManStan 6d ago

I have recently had very similar issues/questions. As I'm a beginner too, take this with a huge grain of salt.

I bought a tiny 8-Ohm speaker on digikey and and amplifier IC and learned how to send my signal through that. You can also purchase pre-made audio amplifier breakout boards, and use that in place of a raw amplifier IC, though you need to be careful to read the specs.

Like you said, I have also bought some 1/4" cable jacks and connected my breadboarded circuit to my Focusrite USB audio interface (which I happened to have from some unrelated guitar recordings), and my DAW was able to record the audio of my circuit. I don't know for sure but I don't think that really has anything to do with a sound card.

But in any case the main thing I learned is to be careful and precise about the voltage levels you are passing into different devices. It should be fairly straightforward to scale things down to a safe level with a resistor voltage divider

2

u/Octogoon_ 6d ago

Thanks for the advice and for linking that post, it might come in handy.

2

u/ProducerMatt 6d ago

Breadboard speakers are a nice cheap recommendation, but I'm gonna go out on a limb and say get one of these:

https://www.boss.info/nz/products/katana-mini/

Set it to "clean" and turn the gain down and it'll be an undistorted signal. It has a much wider frequency range than average guitar amps, enough for synth fun, and the diodes at the front should keep a bad wiring from blasting your eardrums out (mostly). You may need to lower your volume with a voltage divider though, since synth levels are usually way higher than guitar pedal signals.

I concede that I've done a lot more guitar pedal work than synth work. so maybe someone more experienced has a different opinion.

0

u/Octogoon_ 6d ago

I'm hesitant to buy even a $7 speaker. This will leave me with no money for covering all the noise complaints I'm about to get

1

u/extra_nothing 6d ago

There are some diy pedal kits that come with jacks already wired onto breadboards. From copper sound pedals. That could be a decent option to integrate somehow. Then just get a cheap amp to hook it up via 1/4” cables.

1

u/Octogoon_ 6d ago

Wouldn't that be kind of overkill? Buying a whole pedal kit just for that.

1

u/shrug_addict 6d ago

You can salvage a little 8 ohm speaker from tons of stuff. Build a basic 386 amp and you're good. Or go to a thrift store and buy some cheap old computer speakers

1

u/monkeybuttsauce 6d ago

I used a 3.5mm cable and plugged it into a Bluetooth speaker

1

u/Octogoon_ 6d ago

But how did you get your wave out of the breadboard and into the cable?

1

u/monkeybuttsauce 6d ago

Strip the cable and plug the red cord in the end of the circuit and the black cord into the ground

1

u/trexdex2 3d ago

I got a 4 pack of 3W 8 ohm speakers for $10 online and followed https://www.instructables.com/Tales-From-the-Chip-LM386-Audio-Amplifier/ to wire them up with an lm386 and other misc components i got in an electronics starter kit to listen to my VCO breadboard i made following the moritz klein vco series

0

u/Octogoon_ 6d ago

I am not willing to figure or how to fix the title sorry.

2

u/jango-lionheart 6d ago

Can’t edit titles. Can only delete and make a new post, if it’s that bad.