Cyrricky's DIY Synth [COMPLETED]

[Sonarch]

What kind of components were you using in this?

[cyrricky]

What kind of components were you using in this?

The main chip was a TTL7404, which is a set of inverters. each inverter was being toggled rapidly, and the resulting wave, when played through a speaker, is a square. The way the pulse was controlled was through the use of a potentiometer which connected the ins and outs of the inverters (as you can see on my schematic on the first page. Note that the schematic does not reflect the finished piece). Varying the resistance using the pot is what lowered or raised the toggle rate of the inverter, thereby raising or lowering the pitch.

[TheSunAndTheRainfall]

I'm kind of gushing over how beautifully simple these oscillators are, oh my god. It's pretty ridiculous haha.

Also, it's too late for this, but next time you solder something you might wanna try using some flux (liquid works best for me) to get soldering points that look like titty bumps. There's also this mesh thing that I don't know the English name of that you can use to desolder. You put it over your heated up solder points and the solder just sticks to it. It's definitely more useful than using one of those desoldering tools that suck up the solder, 'cause that ones can mess up your copper tracks if you're working with a PCB. Plust I find them awkward to use.

Oh god what kind of synth should I build, i'm drowning in a sea of options, and also schematics I don't understand.

It really depends on what kind of oscillator you wanna make, and the level of difficulty you're looking for. Oscillators like this one are awesome because they're simple to make, and operate on fairly basic principles, but if you wanna go more advanced you're probably gonna end up messing with operational amplifiers, and that's not something I'd recommend messing with if you haven't yet studied them, because there are just SO MANY WAYS they can go wrong. From not doing anything to physically hurting you. I only barely understand op amp basics and I'm shitting myself at the idea of attempting to design my own oscillators. The possibilities are endless with these things.

So if you're planning to design and present your own and don't want to mess too much with ridiculous electronic concepts, I'll agree with FLAOFEI and suggest that you look up simple square wave oscillators like this one. Hell, you can even start off with this exact one, and give it a little variation if you make a few filters for it, and it would still be fairly simple and fun to make. Who knows, maybe you could look into making one based off LM555 chips and get creative with the duty cycle and stuff.

If you're following a pre-made schematic and don't understand it 100%, make sure you at least trust the source, and get the exact same components it asks for. I can't stress enough how important this is. Even if you find another chip that in theory does the same thing as the one you were told to get, you can run into a lot of trouble if you carelesly connect say, CMOS with TTL.

If you're studying electronics at school, I'd strongly advise you to take up any schematics you find or design with a professor and talk them out to see how viable they are.

[Sonarch]

Oh god what kind of synth should I build, i'm drowning in a sea of options, and also schematics I don't understand.

It really depends on what kind of oscillator you wanna make, and the level of difficulty you're looking for. Oscillators like this one are awesome because they're simple to make, and operate on fairly basic principles, but if you wanna go more advanced you're probably gonna end up messing with operational amplifiers, and that's not something I'd recommend messing with if you haven't yet studied them, because there are just SO MANY WAYS they can go wrong. From not doing anything to physically hurting you. I only barely understand op amp basics and I'm shitting myself at the idea of attempting to design my own oscillators. The possibilities are endless with these things.

So if you're planning to design and present your own and don't want to mess too much with ridiculous electronic concepts, I'll agree with FLAOFEI and suggest that you look up simple square wave oscillators like this one. Hell, you can even start off with this exact one, and give it a little variation if you make a few filters for it, and it would still be fairly simple and fun to make. Who knows, maybe you could look into making one based off LM555 chips and get creative with the duty cycle and stuff.

If you're following a pre-made schematic and don't understand it 100%, make sure you at least trust the source, and get the exact same components it asks for. I can't stress enough how important this is. Even if you find another chip that in theory does the same thing as the one you were told to get, you can run into a lot of trouble if you carelesly connect say, CMOS with TTL.

If you're studying electronics at school, I'd strongly advise you to take up any schematics you find or design with a professor and talk them out to see how viable they are.

Thanks! What I need to do is come up with a project and present it to my teacher before building it, so I have to decide what kind of synth I want to make. Since i'm not terribly familiar with electronics, I'd like to stick to something fairly simple. I should just settle on something so I can make sure I understand how it works and all that. I'll look into a square wave synth.

And my problem with the schematics I don't understand is i'm just trawling the internet trying to research synths so I can understand how they work on a basic level, and I end up seeing all sorts of stuff having to do with different types of synthesis and overly-complicated designs. I want to keep it pretty simple, as I said.

Anyway, I'll focus in on a simpler sort of square wave synth and see what I find with that.

[ScarabOfficial]

Hey guys! I have always wanted to take apart a c64 to make a synthesizer using its SID chip. I found this complete DIY guide online: http://www.ucapps.de/index.html?page=midibox_sid.html At the bottom of the page there is a link for the details of each part of the synthesizer. I plan on starting as soon as school gets out.

[itroitnyah]

haha, good luck with that, Scarab Looks like it could be quite the adventure, especially if you screw up, lol

[Ocular]

haha, good luck with that, Scarab Looks like it could be quite the adventure, especially if you screw up, lol

Exactly. (no pressure)

[ScarabOfficial]

Yeah, depending on how many features I decide to add will determine the difficulty. Over winter break I built a custom arcade controller aka "fightstick" for SSFIV. I had so much fun making it that I want to try something music related.

[Sonarch]

I've been doing a lot of research and stuff, and what i'm learning is that (sorry if all of this is blatantly obvious, i'm still getting a lot of the basics down) a synth has a few main parts:
-An oscillator, to generate the waveform to be manipulated
-A VCA (Voltage Controlled Amplifier) to control the volume
-Filters, to alter the original wave to more interesting forms
-Some other stuff like envelopes and LFOs to modulate the signal farther

and I'm having trouble finding a synth design, so I figured I could just get/build all the separate parts. Anyway, I found a guide for building a square wave oscillator that I think looks doable. What do you think?

http://www.instructables.com/id/Build-a-Square-Wave-Oscillator-Part-1-of-DIY-Mod/#step1

[ScarabOfficial]

Just to let you guys know I am following through with my plan. I bought some old commodore64s and ordered the pcb and components I will need to get started. This will definitely take me a few months and I may not finish this summer, but like itroitnyah said it will be quite the adventure. This will be my last post on this page. I will create a new topic where I will keep anyone who is interested up to date with my progress.

EDIT: I just spent two hours typing up complete documentation for my project, I went to preview the post but MLR kicked me off the page and did not save my work.

EDIT (again): this is the link to the page. Not as long as my original write up but it gets the basics out of the way: viewtopic.php?f=13&t=8326&p=123220#p123220

[cyrricky]

Sweet~!