Buddy's Breadboard and Circuit Design Notes - You May Learn Something

steviejr92

Well-known member
A lot of the guys here, including Robert, use DIPtrace. There is a free version for non-commercial used. I've fooled around with it a bit, but since there are others here who are already good at it, I usually defer to them. Fig knows where to order boards.
DIPtrace you say.....Im going to look into that!
 

Chuck D. Bones

Circuit Wizard
LoL.
Sure, why not? My main computer is coming up on it's 8th birthday. The last 5 computers I bought were used. All are still running strong.

Hey Sandy, sorry to side-track your thread.
 

BuddytheReow

Breadboard Baker
If you've been following this thread since the beginning you've noticed that my breadboard has changed dramatically. My first board was a few breadboards on top of some cardboard that was duct taped together. Those were the good ol days....NOT! Then I upgraded to a protoboard which was a godsend in and of itself. Having the protoboard itself was nice, but it needed to be mounted on something so I can more easily pick it up off a table instead of trying to get my fingernails under the board. So what did I do? I mounted it on some scrapwood and rounded off the corners with a router, which definitely helps. I've got a tayda order coming which will help attach a 9v battery to the power socket. My current power supplies are mounted under my pedalboard and on my workbench.

I've got a few ideas brewing just like @fig to make the breadboarding experience better, but I need to mess around and try out my ideas.

Anyways, it's all mounted and one of the ideas is to make a small test speaker just to make sure my creations pass signal. So, I built a Ruby amp to test the speaker. It works nicely and may make this a more permanent fixture on my prototype breadboard.
1669834524501.png
1669834496766.png
 

BuddytheReow

Breadboard Baker
While many of us here like to show off their builds and success stories, it's equally important to mention your failures as well. Why? It helps others to realize that not everything you touch turns to gold. New to pedal making? I'm sure you've had a few bumps along the way or you just got lucky (I don't fall into this category).

I'm sharing this just to show the amount of time needed to pull a circuit out of thin air. The internet is an excellent resource, but it can also provide misinformation as well. I'm currently on the warpath of designing a second 1-Knob fuzz so I can put 2 in an enclosure and make them switchable with only 1 volume pot. The NUT FUZZ was a nice one that I cooked up. I'm toying with the idea of a more octave up heavy fuzz. I stumbled upon this topology from David Morrin's site.
1669935238530.png

Seems simple enough, so why not try it out! With no values from this picture I did some digging and noticed this is similar to the Fender Blender for this particular stage. Resistor values I used are identical on both the collector and emitter, so I went with 6.8K. Fender Blender caps were 10u so I duplicated that as well. The diodes from memory work best when the voltage drop is small, so I used 1n5817s. This stage by itself doesn't pass signal very well and needs an input gain stage. Throwing a shunt feedback amplifier with distorted tone in there produced something, but not as octave-y as I'd like. Sigh. Perhaps I should go back to the drawing board or just pull the trigger on a fuzz face/DAM Meathead derivative of my own, but make it gnarlier.

Anyways, here's 2 projects on my breadboard. One is what I described above and the other is a circuit I cooked up from @Chuck D. Bones contest early this year. The PLOPS OF DOOM. It still needs some tinkering to get it to work the way I want it to, but the "stock" circuit is ok and needs some oscillation tampering. You can read about it here. https://forum.pedalpcb.com/threads/what-another-contest.10105/page-10#post-101594

We need another circuit design contest. That was a lot of fun.
1669935803049.png
 

BuddytheReow

Breadboard Baker
I've got a project where I need more than 9 volts, but I only have a 9v power supply. Here's a charge pump based on the protoboard's power section. I need to test the layout myself, but it should work. I want to put this in a 1590b with some other goodies. When I get a few minutes of bench time I'll see if this works. Note the 2 cuts under the IC itself. Yes, you won't get 18v since you'll lose a bit of voltage due to the diodes, but it's close enough.

Edit: Layout is verified and updated with an additional cut.

1670203664524.png
 

Attachments

  • 1670120161243.png
    1670120161243.png
    58.5 KB · Views: 12
Last edited:

BuddytheReow

Breadboard Baker
Tayda order came today. With my mounted protoboard, I finally was able to make my battery a plug in instead of pulling out cables from under my pedalboard. It works rather nicely, don't you think?
1670274635284.png
 

BuddytheReow

Breadboard Baker
Trying to upgrade my bench and prototyping. This is a power amp that @fig graciously sent me so I could hook up a breadboard to a speaker on my workbench. The power supply I have is 9v daisy chain, but I put the charge pump I posted above in it to increase the headroom. I still need to dial in the gain/volume to minimize the distortion. This is getting "mounted" next to a shelf to make it more permanent until I find a better idea.
1670274777149.png
1670274798126.png
 

BuddytheReow

Breadboard Baker
ZENER DIODES

What are they? Why should I care? How are these used in guitar pedals?

All excellent questions! Let's dive in to see what all the fuss is about. No graphs or complex math here. Read on to learn more!

I took the time to figure out (with a little Google help) about these and how I can apply it to a project I'm currently working on. If you want to read more about my project then check this out! It's going to be an ultra-breadboarding experience that I may tweak later on down the road.

Here is the schematic symbol for a zener diode.
1670857293008.png

For this post and purposes of my project/experiment I pulled out a bag of 9.1V zener diodes (1N4739). Putting them through my TC-1 tester shows there's nothing special about them at all with a simple voltage drop of 0.7V. The tester confirms the little black ring is the cathode.

1670856893661.png

That's weird. I bought these for the 9.1V purpose. Hang on! We need to talk about "zener" breakdown voltage. What is this? Well, if you run some small current from anode to cathode you will see the result above and the diode "steals" about .7 volts before current passes through. What happens when you run current in the opposite direction? Here's where the magic begins....

Whenever you want to test a diode, ALWAYS make sure you have a current limiting resistor (CLR) of some kind. For me, I used a 470 ohm resistor.

We can arrange the CLR and diode to test where this voltage drop occurs. Like this. Your DMM should be where V Out is.
1670858084749.png
As the voltage/current passes through it hits the diode and doesn't allow anything to pass UNTIL it reaches the 9.1V threshold. Anything above that voltage gets passed through the diode.
1670858171358.png

As an experiment, I threw a passive buzzer at the end of this circuit to act as an overvoltage alarm. The buzzer needs about a Volt in order to kick on.

Pretty neat, huh?

Ok. Let's flip the diode and resistor around to look like this:
1670858329407.png

This configuration will then act as a faux voltage regulator. A great way to protect your circuits from accidentally putting too much juice into it. Again, use your DMM at the V Out point. You can see I'm giving it 10V, but only about 9V are coming through. That's because once the diode reaches it breakdown voltage anything over that gets thrown to ground.

1670858477261.png


Pretty cool, huh?

Ok. Now the question you've really been asking. "How does this apply to guitar pedals?" Let's take a look at a SHO (Super Hard On) schematic. This is the PedalPCB CrackleJack, or at least a portion of it.
1670858724056.png
See anything familiar yet? That 1N4739 is a 9.1V zener diode that acts as a voltage regulator! As the current passes through from above my little snippet through R2 and into the gate of Q1 it has to touch the zener diode. Anything over 9.1V applied to Q1 will automatically get dumped to ground and saves your BS170 from getting fried by accidental static discharge.
1670858879483.png

The same concept is true for all zener diodes. A word of caution. Make sure you're orienting the diode the correct way in order for these little circuit legos to work. Otherwise you may accidentally fry one like I did testing this out.

The more you know.....

BuddytheReow
 

BuddytheReow

Breadboard Baker
Here's another charge pump I put together on a breadboard and it works nicely. Utilizing the charge pump already on the protoboard I was able to (with a little help from Google) turn a 9v input into -9V, 18V, and 25V. I tried the next step up and hit about 35V and panicked since my capacitors are only rated at 35v.

1670882669626.png

I then took a bit of time to draw a vero layout since this is going on my BuddyBoard project I'm working on. This isn't verified yet, but it looks ok to me so far. If it doesn't work I'll have sacrificed 5 electro caps. Not that they're expensive; I just don't have a lot of 10uf ones.

Edit: This layout is verified and works nicely.
1670882858300.png
 
Last edited:

BuddytheReow

Breadboard Baker
A while ago I put together a simple, but gnarly one knob fuzz, the Nut Fuzz. See post #208. I want to put this in an enclosure with another one knobber, but still gnarly. I think I've found it. I went through a lot of my old stripboard builds from when I was starting out and during quarantine. This is the Phantom Octave fuzz I built from tagboard effects. These 2 will get boxed up when the time comes. Both of these shine with a detuned guitar IMO.
1672858428275.png
 

Sturdag Lagernathy

Active member
Definitely gonna try this one! The Ultrastoner was a great recommendation, totally right about the EQ on that one. Have you checked out the Mountainking Megalith? Think you'd dig it!
 

Feral Feline

Well-known member
Apparently I need to fry a few transistors with some backwards diodes.

I just read post #234 and when I finished I noticed I'd already given it the thumbs up — so I must've read it before and not learned the lesson well enough to remember it and realise I was re-reading the post.


So I guess this missive is really just me trying to say:
Thanks @BuddytheReow, for all the tutelage you've provided us forumites, and public-lurkers alike.
 

BuddytheReow

Breadboard Baker
Now that my BuddyBoard is up and running, I decided to go through my blank PCBs that need to be built and breadboard them. A "try it before soldering it" scenario. This is a Madbean Pig Butt, which is essentially the Dream Fuzz here (Opamp Big Muff). The only difference that I could see is the tone bypass switch (spdt vs dpdt). I see the logic in both. This is the stock circuit and works pretty well for what it is. I may try to add a MID control in the tone stack and tweak some other values before committing to solder.

I also picked up some smaller jumper cables for pots/switches. They make the board look a little nicer IMO. I still need to get some F/F smaller ones too, but that will be on my next Tayda order soon.

1673392319107.png
 
Top