Prentiss Effects

The 1776 Unicorn Breath Buffer is based on the buffer circuit in the famous Klon Centaur but with a little something extra that makes it a really cool/handy little project.  I'll be going over the bare bones of why you would want a buffer in your signal chain and then what makes the Unicorn Breath unique

What a buffer does...

Everyone's heard the debate over buffered vs. true bypass pedals so I won't be going over that in this post. But general consensus is that true bypass is great, unless you have a bunch of cabling and pedals between you and your amp. The extended cable lengths (through cable capacitance and signal impedance) create a low pass filter that cuts off more of your high end as the cable length increases. A buffer near the beginning of your signal chain alleviates this issue by lowering your signal impedance which raises the cutoff frequency of the high pass filter. I won't go into any more detail on that here, but if you'd like to know more then leave a comment below. On to the board!

Unicorn Breath Buffer

There's a bunch of reasons I like the Unicorn Breath. It's designed around being a DIY project so there are some aspects of the board layout that are really geared towards the builder. That being said, I'm just going to go through my favorite things about it.

1. It's really small. The board itself is only 1" x 1". This makes it perfect for small boxes like the 1590A or 1590LB. It's also a great size for modding pedals like the Ernie Ball VP JR because it fits neatly inside the faceplate. 
2. It has the LED board mounted. I like this because I can just wire in the LED without thinking. Plus I can mount my LED without a bezel if I want to. 
3. Uses a dual op-amp. Most Klon buffers call for a single op-amp. This uses a dual op-amp pinout which is a more common part that you're more likely to already have (hooray for no special order parts!).
4. Voltage buffer. Your reference power voltage is buffered. This means that if you were to use the Vref on the board in another circuit, then the current draw wouldn't be an issue. It's not strictly necessary for this circuit, but it's a nice feature and uses the other half of the op-amp.
5. Extra ground ports. I like have extra places for ground so I can wire my power supply to the board as well as my jacks rather than having to snake wires all over the place. Plus most people don't wire a buffer as true bypass, so you can do all your connections to the board.  
6. Tight layout design. There's no wasted space on the board. All the components are neatly aligned with no strange spaces in it. It's just quite nice to look at both before and after it's been populated.

As far as sound goes, it's a buffer. Because it's IC based it's going to be unity gain (transistor buffers tend to have a tiny amount of loss). If you aren't currently running a buffer somewhere in your signal chain then build one of these. You'll get some high end back that you didn't have before which may mean tweaking your knobs a bit, but it also means you'll get consistent sound regardless of cables or number of pedals.

Overall, I really like this board. It's an incredibly useful circuit and the layout is just great. It can fit in a small box that won't take up a bunch of room on your board and your getting a great quality IC buffe. Plus, it's a fun, quick build due to the low parts count and layout. 

Here you'll find my most up-to-date list of resources for parts. There's also a description of each of the vendors with stuff to look for and avoid from each. Lastly, there will be a breakdown of how I usually order parts for a build.

Vendors 

Tayda Electronics

This is a great resource for passive components (resistors, capacitors, potentiometers, etc.). They are based out of Colorado but also have a location in China that handles a lot of their orders. I've never had to wait more than a week for a shipment to arrive and I live on the east coast.

They have the lowest prices of anyone I've seen for components in general too. Most of their potentiometers come with a plastic covering on the back (a.k.a pot condom) that prevents your PCB from grounding out on them. In addition, you can buy resistors in packs of 10 for as low as $0.01/each. They have a good selection of capacitors (film, box, electrolytic, monolithic ceramic, and ceramic disc). There's also a decent selection of axial caps that carry some nice mojo to them. I also like the selection of opamps they carry and the TC1044SCPA charge pump all of which are incredibly well priced.

This is a great place if you really want to try something out without putting a bunch of money into it. There's a minimum order of $5 but that usually gets you at least a pedal's worth of parts.  Their customer service is quite good as they usually respond within a day. If they get something mixed up in your order they will usually give you a nice store credit or refund (store credit is usually higher).

On the downside, some of their transistors and diodes, mostly JFETs like the J201 and 2N5457 as well as germanium diodes, have been proven to be counterfeits. I highly doubt that was intentional on their end. The Chinese market, where they get their parts from, is flooded with fakes so it can be quite hard to discern the real ones sometimes. Plus those components can still work in your build, you just have to bias the JFETs properly and try different diode combinations.

Their enclosures can sometimes be on the cheap side. However, they are starting up a new finishing department which could be really cool. They do already provide enclosures in certain colors and buffed.

What to buy:

• Resistors
• Capacitors
• Diodes
• Transistors
• Opamps
• Potentiometers
• Power Jacks
• Wire (stranded and solid core) 
• LEDs (and bezels)
• Knobs
• Sockets (to swap out ICs, transistors, diodes, etc)

What to watch out for:

• JFETs
• Germanium components
• Bare enclosures
• Input Jacks

BLMS

Lawrence Scaduto runs the best shop on the market for enclosures, switches, input jacks and cool knobs. He also has one of the most hilarious names in the industry: Bitches Love My Switches. Aside from that, Lawrence also carries some helpful extras like daisy chains, patch cables, 3PDT daughterboards, etc.

To top it all off, if you live in the US then he does flat rate shipping on all his items. I've purchased 50 3PDT switches, 5 true bypass looper enclosures, 120 input jacks, and shipping only ever costs $5.99. He usually ships same day and I've never been waiting more than 4 days for anything I've ordered.

Get on his mailing list as he does updates on new products and sends out sales on items he's clearing out.

What to buy:

• Anything and everything.

What to watch out for:

• Nothing. He lets you know what the quality of each item is in its description.

Small Bear Electronics

Small Bear is one of the most recommended sites for builders. They have everything you need and then some. If there's an obscure part you need for your germanium fuzz then they have it. This is where I go for more obscure or out of production ICs and transistors. You can purchased matched JFETs and germanium transistors for fuzz builds (they even sort them by what type of fuzz they'll work well in).

The one downside is that they are a bit pricier than other retailers. But considering you won't have to buy 15 germanium transistors to find two that match for your fuzz build it's worth the extra cost.

What to buy:

• Germanium anything
• Specialty ICs
• Finished enclosures

What to watch out for:

• Nothing in particular. You'll probably want to buy passive electronics elsewhere because of cost. But everything Small Bear sells is good quality.

Mammoth Electronics

Mammoth Electronics is another one of the more popular sites for DIYers. It's geared specifically towards guitar effects rather than sites like Tayda and is really easy to navigate. They have a wide selection of effects kits and partner with some really great PCB designers like Grind Customs FX. On top of that, there's a fantastic selection for enclosures. They have the typical variety which can all be custom drilled and painted for you (for a reasonable fee) and a huge selection of other sizes as well.

Their IC and transistor selection is top notch as well. There's no counterfeit parts to be found here and have a good selection of discontinued JFETs (J201 and 2N5457) required by a lot of amp-in-a-box builds. They also have one of the widest switch selections available. Their 3PDTs are differentiated by grades rather than the standard "Taiwan Blue" switches available at most other retailers.

Mammoth is a bit pricier than sites like Tayda but that's mostly due to being a US based business. While Tayda saves on overhead by employing some overseas workers, Mammoth is based out of Oklahoma and does all of it's own custom orders (mostly enclosures) in house for quality control. They also have to factor in things like parts testing to make sure they aren't sent a batch of fakes, which does add cost. So while your order may be a bit pricier from them, you know what you're getting is the best quality out there.

What to buy:

• Enclosures
• Transistors
• ICs
• DIY Kits
•  Switches

What to watch out for:

• Nothing. Although your passive electronics are usually not a quality concern so you can buy from places like Tayda for a much lower price (order double if you're concerned and it will probably still be cheaper).

Summary by Parts

Passive Electronics

Resistors - Tayda Electronics
Capacitors - Tayda Electronics
Potentiometers - Tayda Electronics
Sockets (for parts swapping) - Tayda Electronics

 Active Electronics

Transistors - Tayda Electronics & Mammoth Electronics
Opamps - Tayda Electronics & Mammoth Electronics
Specialty ICs - Small Bear Electronics

Hardware

Input Jacks - Bitches Love My Switches
Power Jacks - Tayda Electronics
Enclosures - Bitches Love My Switches & Mammoth Electronics
Footswitches - Bitches Love My Switches & Mammoth Electronics
Knobs - Bitches Love My Switches & Tayda Electronics
Toggle Switches - Tayda Electronics & Mammoth Electronics
Wire - Tayda Electronics

My Order Process

This is how I typically separate parts of my order for a build.
Tayda Electronics - Resistors, capacitors, potentiometers, ICs, general purpose transistors (not JFETs), wire, toggle switches, sockets, and knobs.
Bitches Love My Switches - 3PDT, enclosure (if I want a basic one), input/output jacks, thinline power jack (since I don't use batteries)
Mammoth - JFETs, specialty diodes, enclosure (if I want something very specific or pre-painted).


Now that you've got all your parts, it's on to the Build Procedure

The two most popular ways of building guitar effects on are PCBs (Printed Circuit Boards) and veroboard (a.k.a. Stripboard). I'll go through the pro's and con's of each so you can decide which is best for you. So let's start with...

Veroboard (a.k.a. Stripboard)

Veroboard is essentially a series of parallel copper strips with holes drilled through them. Any components soldered in the same row will share a connection. You can cut the copper traces on the veroboard to expand the number of possible junctions for components or you can run jumper wires from one to another to expand a row. A lot of DIY sites use veroboard to create layouts. The reason being that it's fairly easy to modify and adapt to different circuits. Since veroboard was developed as a prototyping tool, it isn't bound to doing one circuit or style or design. It's also very inexpensive (0.66 a piece at Tayda Electronics)

The downside of veroboard is that it can be finicky. If your circuit doesn't work then it could be that you didn't cut the trace properly, or you accidentally soldered two rows together, or  you soldered your jumper wires to the wrong rows, etc. The board becomes something you have to troubleshoot in addition to the normal checks for a PCB.

In the end, the price and adaptability of veroboard makes it a very common framework for DIYers. If you decide to mode your Tubescreamer with a couple more resistors then you can simply add another row or column to the layout and your good to go. Just be ready to spend a little more time when fault diagnosing your circuit if it doesn't work right away.

PCBs (Printed Circuit Boards)

PCBs are usually designed for a single circuit. Traces are etched into copper and then a coating and silk screen are placed over top to prevent the traces being damaged (amongst other things). Some cool things about PCBs are that they often have board mounted components like switches and potentiometers which saves having to solder a bunch of wires. It also makes fault finding a lot easier since your layout ends up being a lot cleaner since you're not having to trace as many wires around the enclosure. If the board doesn't work then they are usually easier to troubleshoot than veroboard since you know the layout works (if you're buying from a good PCB vendor) so it narrows things down. In addition, they also have figures on the top showing you where all of your parts go so it can be significantly faster to populate a PCB with parts since you don't have to count out to which hole you're putting the part in like you do on veroboard.

On the other hand, they are pricier than stripboard because they have to go through a design and fabrication process. But they are much more reliable because of this. Designers also have an easier time implementing noise reducing techniques than in veroboard so you can get a quieter circuit.

I thoroughly enjoy building a pedal from a well designed PCB (although having veroboard is great when I want to build something in a hurry). They usual work the first time around and if they don't then you know you screwed something up. If you're looking for a good place to order PCBs then here are a couple of my favorites.

• 1776 Effects
• Aion Electronics
• Fuzz Dog
• Madbean Pedals 

Once you've decided which way you want to build, you can start looking at Parts Sourcing