Nooby McNooberson Wants To Know!

[David Scott]

I came across this forum by looking at the Music From Outer Space site. After discovering the music of Raymond Scott, I decided to create my own synthesizer. Even if I make one single modular unit, I would be happy with it. My main question is this:

Can I just use a solderless breadboard for my mini sound lab? Since my plate is already full with trying to learn about circuits, I was hoping to cut a few corners and not have to solder everything piece by piece. I already have a pretty cool case picked out and a basic idea of what I want to create...I just need some direction. I know there's lots of useful info in this forum, but at the moment it's pretty overwhelming. I read a bunch of them, but at the moment it's still Greek to me (until I get the hang of it and understand the terminology a little better). I realize this will be a time consuming project and I'm ready to hang in there until it's done...but I'm not sure what foot to put forward first (mmm..."my best one?" as the saying goes?).

That's all for now. Let me know about the breadboard thing so that I can start buying my pieces and parts tomorrow. Thanks in advance.

[toybox]

Id just solder it is the easy part the hard part is wiring it up so i don't think you will be cutting corners and every thing is solid

[choklitlove]

for a first project, to learn, and for something that is really useable, i'd do the WSG by the same guy as the sound lab. it's simple enough to breadboard if you want, but it's just as easy and educational to do a PCB.

http://musicfromouterspace.com/analogsynth/YOUR_FIRST_SYNTH/YOUR_FIRST_SYNTH.html

don't let all the "noob" stuff fool you. this is a real synth and very much a real instrument. good luck!

[David Scott]

I was going to do a WSG anyway...but my sights are already set a little higher.

So, you're saying that the breadboard thing isn't a good idea for a modular unit? If it holds everything in place, what's the difference? There will be a lot of trial and error, so I figured it would just be more simple to unplug whatever doesn't work right and find the right spot for it.

Also, is there a diagram somewhere on this site that explains all of the symbols on a circuit diagram? That would be helpful as well, since I don't know jack.

[shawn]

breadboards can be more expensive if you plan on going that route with a modular synth. It's best to learn how to solder and just use perfboard.

[jksuperstar]

I think at $30 for the PCB, you'd be hard pressed to save the money by buying breadboards. You will need a bunch of them to get all the connection points you need. And the PCB will save you most of the wiring. And thus mistakes.
Soldering isn't very difficult, especially thru-hole designs (no surface mount parts). So don't let it intimidate you. I would think, even as a beginner, you coud learn how to solder and make a full soundlab in less than a week, only working a little each day.

[fonik]

[Uncle Krunkus]

I agree,
get a soldering iron (25W) and just start doing it. Your soldering will never improve until you get some practice, so it doesn't help to put it off. Bread boards are great for testing out ideas and checking designs, but they are inherently prone to change, and something will come loose or get shorted at some point if you use one as a long term solution.
I also agree about the wiring up of controls being the bigger challenge. And sorting that out on a breadboard is not an option anyway. Your gonna have to solder time.

[David Scott]

You guys have been very helpful...

And since you're all encouraging me to solder every piece, expect more stupid questions in the near future.

Another question:

Is it possible to add an external guitar trigger for the sound module once the original one is finished? I looked at the schematics on the guitar circuit, and was wondering if that would be something that can be made at a later date in a smaller unit that sits next to the main module...that way I can unplug the keyboard, plug my guitar into the guitar unit and then plug that into the sound lab. I know I'm biting off more than I can chew at the moment, but I'm trying to figure out exactly what I'm going to build and what it's purpose will be.

[Uncle Krunkus]

Virtually all synths, especially the SoundLab, can be expanded or have modules temporarily connected to them once the basic system structure is finished. Keep in mind though, that the guitar input module buffers the guitar's signal so it can be injected into the SLs VCF, and outputs a gate to trigger the ENV on the SoundLab. The overall effect is similar to an auto wah pedal.
It does not, track the guitar's frequency and convert that into a Control Voltage to keep the VCOs in tune with it. That is a much more complicated and twitchy kind of interface.

[David Scott]

Ahh, I see...

I was wondering how that worked. I saw the Pink Floyd video Live From Pompeii, and David Gilmour was running his guitar through some type of module that made some pretty fat analog sounds as he played through it. I thought the schematics I were looking at were similar to whatever he was playing through. Also, John Frusciante used something similar for the last RHCP album.

I'm still very interested in building my own synth. How does an external keyboard connect to all of this? What kind of jacks do you use, what kind of keyboards, etc...?

[Uncle Krunkus]

You either use a keyboard which outputs a Control Voltage (CV) & a Gate. Or you use a midi keyboard and run that through a midi to CV & Gate converter. The CV is a voltage signal which tells the Oscillators what frequency to run at. (It's usually a 1Volt per Octave signal (1V/Oct) which has 0V on middle C (I think?)) The Gate signal sits on 0V until a key is pressed, then it jumps to +V (usually 5 to 12V). It stays there until the key is released, when it drops back to 0V. It is all about timing, and controls the starting and stopping of the Envelope generators, (sometimes known as ADSRs (Attack, Decay, Sustain & Release) they, in turn, use another CV to open up the VCAs (and sometimes other CV controlled modules) which control the volume.

[David Scott]

Thanks...that was very helpful. I don't want my noobishness to suggest that I'm not taking all of this in, because I really am. That last bit of information was enough for me to get a grasp on how it all connects together. I have a local electronics store working on a parts list, I'm about to get started working on the case, and at nights I read as much as I can about circuitry. It shouldn't be long before the project gets fully underway. Thanks, guys!

[David Scott]

A local electronics store is taking the time to locate all of the parts needed for my project. I am using this design for my first one ( http://www.musicfromouterspace.com/analogsynth/SOUNDLABMINISYNTH/soundlab.html#BUYAPARTSKIT ). However, they said that they do not have 1% resistors, only 2%. Will this work in it's place?

Also, I need to know what is the voltage of the capacitors. I was assuming everything was 9V (since that is the voltage of the batteries powering it), but like the subject line says, I'm a real noob at this. I'm trying to learn as I go, and this is one of those points where I have to just admit my ignorance and ask all of you. Thanks in advance.

[ian-s]

Cap voltage is a maximum rating so anything rated higher than your intended voltage is ok, so long as it fits the board.

The % rating on resisters is tolerance, so a 2% 100K might be anywhere between 98K and 102K. If your doing the full temperature compensated VCO thing, you might want to hold out for the 1% but it's not that much of a problem.

[David Scott]

Okay, got it.

But I still don't know how to tell what the cap voltage should be. On the page that I linked my previous post to, where does it show that info? You're not wasting time explaining this all to me...this info is going to good use, and it's much appreciated.

[fonik]

don't care about the cap voltage. the voltages running through the soundlab are far below the limits of the caps you buy. the normal ratings are 16V, 25V, 35V, 63V and more. so even a 16V rated cap will do...
usually DIY music electronics are powered from -15/0/+15V or -12/0/+12V for modulars and 9V or 5V for smaller project (i.e. stompboxes) so you don't have to care about that...

[v-un-v]

[David Scott]

Wow, man...that thing is truly intimidating.

And thanks for the tip, fonik. I'm going to owe a lot of credit to you guys once it's done.

I just called the electronics store again, and he said the smallest ceramic capacitor is 50V...will this present a problem? Also, he asked if it had to be ceramic, or could it be a regular capacitor. I told him I'll have to check with "my people" on it.

[Scott Stites]

LOL, those were the days. Of course, it still doesn't look all that different now, just more hardware to go along with the flotilla of breadboards.

As for the 2% resistors - you could just buy a scad of them and sort them with a DMM - you'll probably wind up with quite a few that are within 1% of the value needed. Alternatively, in a lot of cases, they don't have to be within 1% of their rated value, but more rather, within 1% of *each other* - say you have a lot of 100K resistors that measure out to 98K - well, those are close enough to 100K to be all right, but more importantly, they're all within 1% of each other.

My advice is to start ordering 1% metal film resistors - you don't have to get them all at one glomp, but get some every time you order online. I get them from Mouser, and in quantities of 200, they're 2 cents apiece*.

The part number is 271-VALUE-RC. So, for a 100K, the part number is 271-100K-RC, a 4.7K would be 271-4.7K-RC and a 3K would be 371-3.0K-RC, etc.

Start out with the really often used values (100K, 10K, 4.7K, 47K, 1K, things like that), and with each subsequent order you make, throw more on pile. You'll get to the point where you don't even have to worry if you have the right value or not - if you don't have the exact value, you probably have two that will work either in parallel or series.

After a while, you'll get a grip on other parts you find yourself using over and over (IC's, caps, switches, etc.). Start a stock of those as well. When you order parts, order one to use and at least one to put into stock. After a while you'll hit critical mass, and you'll be at the point where you can download just about any schematic and breadboard it without even worrying about if you have the parts or not. I've long since reached critical mass, and it's a blast.

Cheers,
Scott

*If you buy 199, it will cost you $17.91. If you buy 200, it will cost you $4.00. That always tickled me.

[fonik]

[v-un-v]

This is a great thread

Just a couple of months back or so I bought about £70 worth of electronics components, and I had completely forgotten about how intimidating this whole business can be- especially buying capacitors (and resistors).

I was stupid enough to fall for that old trick of the bulk pack, only to find that several really important values like 100k or 4.7k were either missing or one only gets 10 of them

Scott, do you reckon that 5% resistors could be avoided- going for metal film instead?

I highly recommend storage- like in the modular drawer type. For ages I just dumped everything in carrier bags (probably because I was always moving house ). Recently I got some rather nice little drawers on ebay for next to nothing. Nice

It's funny, because if you're reading about making ADHDboy's stuff (Mr Ray Wilson), it comes very quickly what components you are gonna have to stock up on!!

[Uncle Krunkus]

I agree Tom,
Bulk bags are generally a rip off unless you're just starting out, and have nothing. Even then there will be things you got in that bulk bag which you still have twenty years later.
Speaking of people's preferred values, does anyone else out there have a favourite resistor?
Mine is 4K7.
Not sure why, I think it might be the colours.

"I talk to the trees!......
That's why they locked me away!......."

[v-un-v]

[Uncle Krunkus]

Yeah, I must admit I'm also a bit partial to a 6M8 every now and then. They are just so cool! (probably because they don't allow much current flow! )