BYOC Mega Chorus & Vibrato Kit User manual

Build Your Own Clone
Mega Chorus & Vibrato
Kit Instructions
Warranty:
BYOC, Inc. guarantees that your kit will be complete and that all parts and components
will arrive as described, functioning and free of defect. Soldering, clipping, cutting,
stripping, or using any of the components in any way voids this guarantee. BYOC, Inc.
guarantees that the instructions for your kit will be free of any majors errors that would
cause you to permanently damage any components in your kit, but does not guarantee
that the instructions will be free of typos or minor errors. BYOC, Inc. does not warranty
the completed pedal as a whole functioning unit, nor do we warranty any of the
individual parts once they have been used. If you have a component that is used, but feel
it was defective prior to you using it, we reserve the right to determine whether or not the
component was faulty upon arrival. Please direct all warranty issues to:
[email protected] This would include any missing parts issues.
Return:
BYOC, Inc. accepts returns and exchanges on all products for any reason, as long as they
are unused. We do not accept partial kit returns. Returns and exchanges are for the full
purchase price less the cost of shipping and/or any promotional pricing. Return shipping
is the customer’s responsibility. This responsibility not only includes the cost of
shipping, but accountability of deliver as well. Please contact
[email protected] to receive a return authorization before mailing.

Tech Support:
BYOC, Inc. makes no promises or guarantees that you will successfully complete your
kit in a satisfactory manor. Nor does BYOC, Inc. promise or guarantee that you will
receive any technical support. Purchasing a product from BYOC, Inc. does not entitle
you to any amount of technical support. BYOC, Inc. does not promise or guarantee that
any technical support you may receive will be able to resolve any or all issues you may
be experiencing.
That being said, we will do our best to help you as much as we can. Our philosophy at
BYOC is that we will help you only as much as you are willing to help yourself. We
have a wonderful and friendly DIY discussion forum with an entire section devoted to the
technical support and modifications of BYOC kits.
www.byocelectronics.com/board
When posting a tech support thread on the BYOC forum, please post it in the correct
lounge, and please title your thread appropriately. If everyone titles their threads
“HELP!” then it makes it impossible for the people who are helping you to keep track of
your progress. A very brief description of your specific problem will do. It will also
make it easier to see if someone else is having or has had the same problem as you. The
question you are about to ask may already be answered. Here is a list of things that you
should include in the body of your tech support thread:
1. A detailed explanation of what the problem is. (more than, “It doesn’t work, help”)
2. Pic of the topside of your PCB.
3. Pic of the underside of your PCB.
4. Pic that clearly shows your footswitch/jack wiring and the wires going to the PCB
5. A pic that clearly shows your wiring going from the PCB to the pots and any other
switches(only if your kit has non-PC mounted pots and switches)
6. Is bypass working?
7. Does the LED come on?
8. If you answered yes to 6 and 7, what does the pedal do when it is in the "on" position?
9. Battery or adapter (if battery, is it good? If adapter, what type?)
Also, please only post photos that are in focus.
Copyrights:
All material in this document is copyrighted 2014 by BYOC, Inc.

Mega Chorus & Vibrato Kit Instruction
Index
Parts Checklist……………………….................…....page 6
Populating the Circuit Board…….................…...…..page 8
Main PCB Assembly..................................................page 17
Wiring……………………………….........................page 19
Installing the IC/Finishing up………………….......page 25
Operation Overview...................................................page 26
Schematic....................................................................page 27

This is what your kit should look like when it’s complete. Your kit may come with
different color capacitors, switches etc. Don’t be alarmed by this. They all still do
the exact same thing.

Parts Checklist for Mega Chorus & Vibrato Kit
Resistors:
2 – 390R (Orange/White/Black/Black/Brown)
1 – 470R (Yellow/Purple/Black/Black/Brown)
2 - 1k (Brown/Black/Black/Brown/Brown)
1 – 2k2 (Red/Red/Black/Brown/Brown)
1 – 2k7 (Red/Purple/Black/Brown/Brown)
4 - 4k7 (Yellow/Purple/Black/Brown/Brown)
2 – 6k8 (Blue/Grey/Black/Brown/Brown)
24 - 10k (Brown/Black/Black/Red/Brown)
4 – 12k (Brown/Red/Black/Red/Brown)
3 – 33k (Orange/Orange/Red/Brown/Brown)
4 – 47k (Yellow/Purple/Black/Red/Brown)
1 – 56k (Green/Blue/Black/Red/Brown)
1 – 68k (Blue/Grey/Black/Red/Brown)
3 - 100k (Brown/Black/Black/Orange/Brown)
2 – 330k (Orange/Orange/Black/Orange/Brown)
1 – 470k (Yellow/Purple/Black/Orange/Brown)
2 – 1M (Brown/Black/Black/Yellow/Brown)
Visit www.byocelectronics.com/resistorcodes.pdf for more information on how to
differentiate resistors.
Capacitors:
1 – 47p Ceramic Disc
1 – 470p Ceramic Disc (may say “471” on the body)
2 – 1n0/ .0010uf film cap (may say “102” on the body)
1 – 3n3/.0033uF film cap (may say “332” on the body)
2 – 6n8/.0068uF film cap (may say “682” on the body)
2 – 8n2/.0082uF film cap (may say “822” on the body)
1 – 27n/ .027uf film cap (may say “273” on the body)
5 – 47n/.047uF film cap (may say “473” on the body)
1 - .47/ 470n film cap (may say “474” on the body)
3- 1uf film cap (may say “105” or “1u” on the body)
5 – 10uf Aluminum Electrolytic
2 – 100uf Aluminum Electrolytic
Visit www.byocelectronics.com/capcodes.pdf for more info on how to differentiate
capacitors.
Diodes:
1 - 1N4001
4– 1N4148

IC's:
5 - DIP 8 Socket
1- TL022
1- 3102 clock driver (3101 used only if 3007 is used)
1- 3207 BBD (3007 is optional)
2 – TL072 or 4558
Transistor:
8 – 2N3904, 2N5088, 2N2222 or other similar transistor with EBC pinout.
1 – 78L08
Trimpot:
1 - 25k
1 – 50k
Potentiometers: SNAP THE SMALL TABS ON THE TOP OF THE POTS OFF WITH A
PAIR OF NEEDLE NOSE PLIERS
3 – B100k (Rate, Shape and Depth)
1 – B10k (Blend)
1 – B50k (Tone)
1 – B500k (Delay)
Hardware:
1 - predrilled enclosure w/ 4 screws
1 – Mega Chorus & Vibrato circuit board
1 – 3PDT footswitch
1 – SPST on-on toggle switch
6 - knobs
1 - AC adaptor jack
1 - ¼”stereo jack
1 - ¼” mono jack
1 - battery snap
1 - red LED
4 – rubber bumpers
2 – lock washers (for in and out jacks)
hook-up wire

Populating the Circuit Board
Step 1: Add all the resistors. Resistors are not polarized and can be inserted in either
direction. Be sure to save the lead clippings. You will need them for the next step.
NOTE: Only add ONE 56k resistor to one of the spaces highlighted in yellow. If
you are using a 3207 BBD, insert the 56k resistor into the space labeled “3207” and
leave the “3007” space empty. If you are using a 3007 BBD, insert the 56k resistor
into the space labeled “3007” and leave the “3207” space empty.

Step 2: Add jumpers to the highlighted areas. This is done by using a small amount of
lead clipping left over from the last step to make a zero resistance connection. NOTE:
The space labeled “JUMP” will be jumpered regardless of what BBD you are using. If
you are using a 3207 BBD, you will put jumpers in both spaces labeled “3207” and leave
both spaces labeled “3007” empty. If you are using a 3007 BBD, you will put jumpers in
both spaces labaled “3007” and leave both spaces labeled “3207” empty.

Step 3: Add the diodes. Be sure to match the end of the diode with the stripe
to the layout on the PCB. The stripped end should go in the square solder
pad. The 1N4148 diodes will go in the 4 smaller spaces. The 1N4001 goes
in the larger space.

Step 4:Add 4 pin IC sockets. Be sure to orient the socket so that the end
with the notch matches up with the notch on the layout. ONLY SOLDER
THE SOCKET! NOT THE ACTUAL IC! This is a socket. The sockets
get soldered to the PCB. The ICs get inserted into the sockets. The actual
IC chip itself never gets soldered. You will insert the IC into the socket after
the entire pedal has been built.

Step 5: Add the transistors. Orient them so that the flat side matches up with the flat side
on the PCB layout. Be sure to insert the 78L08 8v regulator into the space labeled “V
REG”.

Step 6: Add the 25k and 50k Trim pots. Note that there are 5 holes on the PCB, but only
3 leads on the actual trimpot. Please do not let this confuse you. This is so that the PCB
can accommodate a variety of trimpots. There should only be one way to fit the trimpot
into the PCB. You do not need to bend the leads to make it fit (unless the leads were bent
in shipping).
You will need to adjust the trimpot when you are finished building the pedal. The 25k
adjusts the circuits bias voltage and the 50k trimpot adjusts the sine wave symmetry. You
start by setting the trimpots at the middle of its rotation or “noon”. This will get you
started and should definitely produce a chorus sound when you plug in for the first time.
You fine tune the bias trimpot by strumming or plucking as hard as you can and dialing
the trim pot till you get the least amount of distortion. If you have a guitar with hotter
pickups, you should use it for this step. You will need to have the wave toggle switch in
the sine position to adjust the sine wave. You do not need any special tools for this. Just
use your ears.

Step 7: Add the film and ceramic disc capacitors. These are non-polarized so they can go
in either direction.

Step 8: Add the aluminum electrolytic capacitors. These ARE polarized, meaning there
is a positive and negative end. The positive side will have a longer lead and goes in the
square solder pad. The negative side will have a shorter lead and a stripe running along
the body of the cap, and goes in the round solder pad.

At this point your board should look like this: ( If built to 3207 spec’s)

Step 9: Add the battery snap. Load the snap wires in the strain relief holes through the
bottom of the PCB and insert the stripped ends of the wire into the solder pads through
the top side of the PCB. Solder on the bottom side.

Step 10: Add wires to the “Ring”, “1”, “2”, “5”, “7” and the two Ground eyelets. Start
by cutting seven 4” pieces of wire. You will want to strip 1/4” off each end and tin the
ends. Tinning means to apply some solder to the stripped ends of the wires. This keeps
the strands from fraying and primes the wire for soldering. Load the wires in from the top
and solder on the bottom of the PCB. But before you strip and tin the wires, you’ll want
to measure them and trim them so that they will be the proper length for connecting to the
footswitch. It would probably be easier to do this after the entire PCB assembly has been
installed into the enclosure.

Main PCB Assembly
Step 1: Flip the PCB over so that the bottom or solder side is up. Insert the
tsix potentiometers, toggle switch, and LED into the bottom side of the PCB.
DO NOT SOLDER ANYTHING YET!!! The LED will have one lead that
is longer than the other. THIS WILL GO INTO THE SQUARE SOLDER
HOLE. Don’t forget to remove the nuts and washers from the pots and also
to snap off the tabs before you do this step.

Step 2:Hold the PCB in one hand so that the component side of the PCB is
in the palm of your hand and the bottom side with the pots and LED are
facing up. Now use your other hand to guide the predrilled enclosure onto
the PCB assembly so that the pots, toggle switch and LED all go into their
respective holes. Once the PCB assembly is in place, secure it by screwing
on the washers and nuts for the pots. Only tighten them with your fingers.
You do not want them very tight yet. Make sure you’ve removed the nuts
and washers from the pots and that you’ve also snapped the tabs off the pots
as well before installing.
Step 3:Turn the entire pedal over so that the component side of the PCB is
facing up. Lift the PCB up off the pots about 2mm just to make sure that the
back of the PCB does not short out against the pots. Make sure the PCB is
level and symmetrically seated inside the enclosure.
Step 4:Solder the pots and LED. You will solder these parts on the
component side of the PCB. After you have soldered them in place, be sure
to tighten up their nuts. Be careful not to burn any of the components on the
PCB. If you do, it won’t harm anything, but it will look ugly.