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L5 PREAMP

WARNING / DISCLAIMER

PLEASE READ THE FOLLOWING BEFORE PURCHASING OR BUILDING THIS PROJECT!

1. NO DIRECT TECHNICAL SUPPORT:

 This project has been verified to be working, and I have done my 

best to provide extremely thorough documentation, including information to help you troubleshoot. But on a 

project this size, I have to reiterate that 

Aion Electronics cannot provide direct technical support for this 

project

 or others. I love helping people bring these circuits to life, but my availability is very limited. If you post 

your question on one of the DIY forums and send me a link, I will do my best to chime in. Just know before 

purchasing this PCB that 

there is no implied guarantee of the final product

, because the biggest factor is 

outside my control: 

you!

 Your experience and your attention to detail are the most important ingredients in 

making sure this works. My role is to provide the recipe and some cooking utensils.

2. IT WILL TAKE AWHILE:

 Be prepared to invest some hours into putting this together. You’ll want to be 

doubly careful when populating the board since it’ll be much more difficult to track down a problem if you were 

to make even the most basic of mistakes (for instance, accidentally using a 10k resistor somewhere instead of 

a 100k). 

You can’t be too cautious.

 I’d recommend measuring each resistor with a multimeter before putting 

it into place. Triple-check your wiring. The more time you spend on the initial build, the less time you’ll have to 

spend troubleshooting.

3. IT’S COMPLICATED:

 As of this writing, this is the largest PCB in the DIY guitar pedal scene. While it is not 

a technologically complex circuit—no BBDs, clocks or LFOs like in vintage EHX modulation effects—there 

are still a lot of things that can go wrong. Hopefully it goes without saying, but 

if you’ve never built a guitar 

pedal before, this shouldn’t be your first

. If you haven’t successfully built at least ten, including drilling the 

enclosure accurately with a template, you may not be ready for this one yet.

4. YOU’VE GOT TO BUILD IT AS IT WAS INTENDED:

 I approached the project as though I was designing a 

completed product for market. Everything has been designed to be built using methods you’d see in a high-end 

pedal (for instance, PCB-mounted pots & switches and components with specific sizes and characteristics) and 

a full bill of materials has been provided so it’s very easy to order all the parts from 

Mouser

. We all build pedals 

in our own style, but with this one, if you try to “freestyle” by doing your own enclosure layout or using parts 

other than the ones specified, you might back yourself into a corner. Please do things my way—you’ll end up 

with a very professional and durable end product and you might even learn a few things in the process!

5. IT’S NOT CHEAP:

 Between the PCB, enclosure, hardware, potentiometers, and the on-board components, 

expect to spend a minimum of 

$100 USD

 and probably closer to $125. Please don’t try to cut corners on the 

parts selection by using poor-quality components or by substituting “close enough” components that you have 

laying around. You’re putting a lot of time and effort into this build, so it’s worth a few extra dollars to use the 

right parts. Expect to order from more than one web store to get everything you need.

6. IT USES A NON-STANDARD ADAPTER:

 This pedal requires an adapter that puts out 

9V AC

, not DC. This 

is the same type of power supply used by Line 6 for their large digital modeling pedals such as the DL-4, and 

they are readily available from Line 6 or from other manufacturers who advertise Line 6 compatibility. Just 

know that 

this adapter will destroy any pedal that is not designed for AC power

. By having an AC-output 

adapter laying around, you run a very high risk of this adapter getting plugged into a non-AC pedal, either by 

you or someone else, since it says on the label that it’s a 9 volt adapter and the “AC” part is easy to overlook. 

I recommend using some colored heat shrink or electrical tape near the barrel tip of the adapter as a reminder 

that it’s different.

Now that you’ve been properly warned: on to the fun stuff!

Summary of Contents for L5 Preamp

Page 1: ...curately with a template you may not be ready for this one yet 4 YOU VE GOT TO BUILD IT AS IT WAS INTENDED I approached the project as though I was designing a completed product for market Everything...

Page 2: ...output straight into a power amp either a dedicated power amp or the return jack of an amp with an effects loop The main difference will be the volume you run it at This thing is capable of enormous v...

Page 3: ...is a patented Moog invention that uses a set of six fixed frequency resonant filters to add a very unique quality to an instrument signal that is unlike any other guitar effect sometimes described by...

Page 4: ...rovided only as a convenience You are responsible for checking through the parts to make sure they are the ones you want and Mouser is responsible for sending you the correct parts I tried to pick hig...

Page 5: ...220R R73 10k R74 3k3 R76 100k R77 15k R78 220R R79 220R R81 10M R82 820R R83 22k R84 6k8 R87 22k R88 3k3 R89 2k7 1 2W R90 33k R91 10k R92 10k R93 47k R94 47k R95 680R 1 2W R96 100k R97 10k R98 1k5 R99...

Page 6: ...resistors so the values have been modified but it is electrically identical 2 Optional I included these three resistors as an experiment to see if the inevitable LED switch noise could be cut down by...

Page 7: ...f the output with a multimeter black lead to the sleeve red lead to the tip The measurement was around 20mV AC I ended up at the 23 4dB setting in the app to get 30mV This probably varies widely depen...

Page 8: ...than 10mA but they are required if you want to test out the power section before inserting the ICs and transistors which is a good idea and they barely draw any power so you may as well leave them in...

Page 9: ...GND 22k 560R GND 390R 300R GND GND 22k 22k 22k 6k8 39k 18k GND GND 10n GND 100n 2M2 GND 10n 10n GND GND C11 C12 1 2 3 MID2 2 3 1 IC5A 6 5 7 IC5B 2 3 1 IC4A R24 R23 R25 R22 R27 R26 1 2 3 FREQUENCYA 1...

Page 10: ...k GND 15k 10n 6k8 33k GND CA3080 1k GND 470k 220R 10k 20k 220pF GND V 10n GND 2N5088 2N5088 3k3 2k 47k V 330R 10n GND 330n GND 100k 68n 2N5457 V CA3080 6k8 15k V 10M GND 820R 100pF 220R 220R GND GND V...

Page 11: ...the placement of the pots switches and other hardware inside the enclosure looking in from the bottom 1590X VOL1 2 5kA TREBLE1 50kA VOL2 25kA TREBLE2 25kB MULTI 25kA MASTER 25kA MID1 2 5kA BASS1 50kA...

Page 12: ...y reasonable so do whichever you think is best For always on LED operation run a wire from the CH pad on the channel switching board the one on the right hand side in the diagram above looking from th...

Page 13: ...ure to secure it while drilling Note that the holes are shown slightly smaller than they need to be so drill out the holes as shown and then step up until they are the correct size for the components...

Page 14: ...s is about 50 bigger than life size The main PCB measures 5 35 x 3 5 The smaller PCB on the left is the master bypass and the one on the right is the channel switching These both inclode on board LEDs...

Page 15: ...x later After it s soldered clip off the excess length of the leads 2 Note on soldering the toggle switch es It will require a good amount of solder to fill the pads Try to be as quick as possible to...

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