Lithium Grim Merlin Instruction Manual

Merlin
Building instructions
V1.1

Merlin v1.1
Manufacturer and product names are mentioned solely for circuit identification, and where applicable their trademarks are the
property of their respective owners who are in no way associated or affiliated with the author. No cooperation or endorsement
is implied.
2
Table of contents
Components ............................................................................................................................................ 3
PCB layout............................................................................................................................................... 3
Bill of Materials........................................................................................................................................ 4
Building sequence ................................................................................................................................... 5
Modifications........................................................................................................................................... 6
Softclipping.......................................................................................................................................... 6
Additional diodes................................................................................................................................. 6
Diodes and Op amp............................................................................................................................. 6
Feedback loop ..................................................................................................................................... 7
Lovepedal OD11 ...........................................................................Fout! Bladwijzer niet gedefinieerd.
Off board wiring ...................................................................................................................................... 9
Effects loop............................................................................................................................................ 12
Troubleshooting .................................................................................................................................... 13
Schematic .............................................................................................................................................. 14
Read this entire manual thoroughly before you start building the effect! Especially the modification
part. Decide before building the effect which version and mods you want to try so that you do not
need to desolder parts later.
Last update: 20-08-2019
Changelog:
V1.0 : Initial version
V1.1 : Added J1, small silkscreen corrections, smaller PCB. Added OD11™and Zen drive™configuration

Merlin v1.1
Manufacturer and product names are mentioned solely for circuit identification, and where applicable their trademarks are the
property of their respective owners who are in no way associated or affiliated with the author. No cooperation or endorsement
is implied.
3
Components
Name
Value
Comment
Name
Value
Comment
C1
47n
MKT/SMF
R1
2M2
1% metalfilm
C2
100p
Silver mica
R2
510k
1% metalfilm
C3
39n
MKT/SMF
R3
3k3
1% metalfilm
C4
1u
MKT/SMF
R4
3k3
1% metalfilm
C5
10n
MKT/SMF
R5
1k5
1% metalfilm
C6
1u
MKT/SMF
R6
3k3
1% metalfilm
C7
47u
Electrolyte 16V+
R7
3k3
1% metalfilm
C8
47u
Electrolyte 16V+
R8
8k2
1% metalfilm
C9
150n
MKT/SMF
R9
10k
1% metalfilm
C10
4n7
MKT/SMF
R10
330R
1% metalfilm
D1
1N4148
R11
Jump
D2
1N4148
P1
A500k/A1M
Gain
D3
1N4148
P2
A10k
Boost
D4
1N4148
P3
A50k
Bass
D5
1N4001
P4
A10k
Boost Tone
IC1
JRC4559
P5
A50k
Treble
SW1
3PDT
Boost footswitch
P6
A10k
Volume
SW2
SPDT
Soft Clipping
SW3
DP3T (ON/OFF/ON)
Additional diodes
J1
Jump
Tim/timmy
SW4
DP3T (ON/OFF/ON)
Feedback loop
PCB layout
A=Log, B=Lin, C=Rev. Log

Merlin v1.1
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property of their respective owners who are in no way associated or affiliated with the author. No cooperation or endorsement
is implied.
4
Bill of Materials
Capacitors
Value
Amount
Type
Rating
4n7
1
MKT or SMF
16V or higher
10n
1
MKT or SMF
16V or higher
39n
1
MKT or SMF
16V or higher
47n
1
MKT or SMF
16V or higher
150n
1
MKT or SMF
16V or higher
1u
2
MKT or SMF
16V or higher
47u
2
Electrolyte
16V or higher
100p
1
Silver Mica or Ceramic Disc
16V or higher
Diodes
Value
Amount
Type
1N4001
1
1N4148
4-7
minimal 4 maximum 7 (see modifications section)
LED
1
Red 3mm
LED
1
Orange 3mm (only for Tim™)
IC
Value
Amount
Type
JRC4559
1
Socket using a DIP-8 socket
Resistors
Value
Amount
Type
330R
1
metal film 1%
1k5
3
2 for LED's metal film 1%
3k3
6
metal film 1%
8k2
4
metal film 1%
10k
2
metal film 1%
510k
2
metal film 1%
2M2
2
metal film 1%
A10K
3
16 mm Alpha pot
A50K
2
16 mm Alpha pot
A500K or A1M
1
16 mm Alpha pot A500k for Tim™A1M for Timmy™
Switches
Value
Amount
Type
3PDT
2
Footswitch, Timmy™uses only 1
DP3T
2
Type ON/OFF/ON OPTIONAL see modifications section
DPDT
2
OPTIONAL see modifications section
SPDT
1
OPTIONAL see modifications section

Merlin v1.1
Manufacturer and product names are mentioned solely for circuit identification, and where applicable their trademarks are the
property of their respective owners who are in no way associated or affiliated with the author. No cooperation or endorsement
is implied.
5
Building sequence
Soldering this board can be very complicated for some people since the solder pads are very close
together. Use a magnifying glass to make the job easier. If you want to experiment with other diodes
then you could socket them instead of soldering them to the board. You’ll need a 20 SIL, break off
the sockets and solder them to the board.
This board is primarily inspired by the Paul Cochran Tim™and Timmy™, but with v1.1 you can also
build a Lovepedal Zen Drive™or OD11™(which all are themselves based on the tube screamer… yes,
nothing is original) using only this single board! If you want to recreate the Tim™then solder all
components. SW3 and SW4 are optional mods (see modifications section). If you want to recreate
the Timmy™then do not solder SW1, C9, C10, R10, P2 and P4. For SW3 you can choose between the
standard SW3 or the original SW3a and SW3b (see modification section).
First decide which pedal you want to build. When making the Tim™/Timmy™you must short J1 with
a spare piece of lead wire. Do not short J1 for the OD11™and Zen Drive™. R11 is only used for the
Zen Drive™, short it for the OD11™,Tim™and Timmy™. Now solder the diodes and then the resistors.
Again, If you want to socket the diodes then skip them and instead solder the sockets for the diodes.
Note: Diodes are fragile!! Do not expose them to heat for too long or they’ll break. Do not blow on
your solder in an attempt to cool it down. That will possibly result in a bad join that might corrode!
Solder the IC socket next and then the small SMF/MKT capacitators, then the electrolytes, then the
1uF SMF/MKT and finish with the C2 silver mica.
Place the IC (and diodes if socketed) and you are almost ready to rock.
Besides the components mentioned in the table on the page 4, you will need:
•2 input jacks. 2 mono jacks if you are not going to use a battery but only the 9V adapter. 1
mono (for output) and 1 stereo jack (for input) if you will be using both a 9V battery and the
9V adapter. If you also want to incorporate the effects loop you’ll need an extra mono jack
and a switching mono jack (see effectsloop section).
•2 x 3PDT footswitch (9 pins) if you are building the Tim™or only 1 if you are building the
Timmy™.
•2,1mm DC jack (isolated).
•9v battery clip (optional).
•22 gage stranded hook-up wire.
•2 x LED if you are building the Tim™or only 1 if you are building the Timmy™, OD11™or Zen
Drive™
•Hammond 1590BB case (or similar) in your favorite color for the Timmy and a Hammond
1590XX (or Hammond 1590DD) for the Tim™.

Merlin v1.1
Manufacturer and product names are mentioned solely for circuit identification, and where applicable their trademarks are the
property of their respective owners who are in no way associated or affiliated with the author. No cooperation or endorsement
is implied.
6
Modifications
Softclipping
SW2 is a clipping mod for all versions. There is no specific order in which you need to solder it to the
pads of SW2.
To SW2
Additional diodes
You can have different choices for your diode switching. SW3 is used standard only for the Timmy™
but can also be added to the Tim™ as a mod. Here is the diagram for the original wiring for the
Timmy™ using 2 DPDT switches. There is no specific order in which you need to solder it to the pads
of SW3.
To SW3To SW3
Diodes and Op amp
You can use other diodes than the mentioned 1N4148. Try LED’s, MA858/859 (very nice!!) or even
1N4001’s.
IC1 can be any dual op amp of your liking. Try the RC4558, RC4559, AD712, MC1458, TL072, OPA134,
OP275, etc, etc.

Merlin v1.1
Manufacturer and product names are mentioned solely for circuit identification, and where applicable their trademarks are the
property of their respective owners who are in no way associated or affiliated with the author. No cooperation or endorsement
is implied.
7
As an alternative for using 2 DPDT switches, you can replace them by only one DP3T ON/OFF/ON
switch to make use of 2 of the 3 switch options of the standard wiring:
To SW3To SW3
Feedback loop
SW4 is an optional feedback loop mod using a DP3T ON/OFF/ON that can be added to all versions.
Although the drawing might suggest to use ceramic disc capacitors, you can use any type you want.
Note there is also an added 47k resistor (these components are extra and not mentioned on the bill
of materials):
To SW4
To SW4
220n
2n2
47k

Merlin v1.1
Manufacturer and product names are mentioned solely for circuit identification, and where applicable their trademarks are the
property of their respective owners who are in no way associated or affiliated with the author. No cooperation or endorsement
is implied.
8
Creating other effect
OD11
Name
Value
Comment
Name
Value
Comment
C1
47n
MKT/SMF
R1
1M
1% metalfilm
C2
100p
Silver mica
R2
1M
1% metalfilm
C3
33n
MKT/SMF
R3
3k3
1% metalfilm
C4
1u
MKT/SMF
R4
3k3
1% metalfilm
C5
47n
MKT/SMF
R5
1k5
1% metalfilm
C6
1u
MKT/SMF
R6
3k3
1% metalfilm
C7
47u
Electrolyte 16V+
R7
3k3
1% metalfilm
C8
47u
Electrolyte 16V+
R8
10k
1% metalfilm
C9
NC
R9
8k2
1% metalfilm
C10
NC
R10
NC
D1
1N4148
R11
Jump
D2
1N4148
P1
A500k
Drive
D3
1N4148
P2
NC
D4
1N4148
P3
A50k
Bass
D5
1N4001
P4
NC
IC1
JRC4558
P5
A5k
Tone
P6
A10k
Level
SW1-4
NC
J1
NC
Zen Drive
Name
Value
Comment
Name
Value
Comment
C1
470n
MKT/SMF
R1
2M
1% metalfilm
C2
100p
Silver mica
R2
470k
1% metalfilm
C3
NC
MKT/SMF
R3
1k
1% metalfilm
C4
100n
MKT/SMF
R4
1k
1% metalfilm
C5
3n3
MKT/SMF
R5
10k
1% metalfilm
C6
470n
MKT/SMF
R6
NC
1% metalfilm
C7
100u
Electrolyte 16V+
R7
Jump
1% metalfilm
C8
47u
Electrolyte 16V+
R8
10k
1% metalfilm
C9
NC
R9
10k
1% metalfilm
C10
NC
R10
NC
R11
1k
D1-5
NC
See Clippingsection
P1
B500k
Gain
P2
NC
IC1
AD712
P3
B10k
Voice
P4
NC
SW1-4
NC
P5
B50k
Tone
P6
A100k
Volume
J1
NC

Merlin v1.1
Manufacturer and product names are mentioned solely for circuit identification, and where applicable their trademarks are the
property of their respective owners who are in no way associated or affiliated with the author. No cooperation or endorsement
is implied.
9
Clipping Diode Configurations
There are really a lot of ways to configure the diodes in the soft clipping section of this effect. For the
Tim/Timmy and OD11 you can use the onboard diode section. For the Zen Drive you will have to use
a separate diode clipping PCB (sold separately) or build your own using a vero board.
Feel free to experiment with different diodes and configurations. You can use the SW3 connection to
add any clipping configuration either by using a switch or by connecting a separate clipping diode
PCB (or vero).
The diode configuration for the Zen Drive™and OD11™can be found below. A and B mart the spots
on the Merlin PCB where you can connect an external board to is you are not mounting any diodes
on the Merlin PCB and/or are not using the SW3 connection.
Zen Drive™Clipping Diodes
OD 11™Clipping Diodes

Merlin v1.1
Manufacturer and product names are mentioned solely for circuit identification, and where applicable their trademarks are the
property of their respective owners who are in no way associated or affiliated with the author. No cooperation or endorsement
is implied.
10
Off board wiring
The biggest challenge of this build is to get all the offboard wiring correct and fit it in a box. Take your
time measuring and testing before you start fitting everything in the box.
Wiring the pots P1-P6 is very simple. The rectangle pad marks pin 1 of a potentiometer. The images
below show how you can recognize which pin is which on a potentiometer. (PS P3 is wired in reverse,
so, for P3 only, connect pin 3 to the square pad instead of pin 1)
You can break off the pin I marked with the yellow circle with a small pair of
pliers.
P1 is a A500k for Tim™ and a A1M for the Timmy™. If you want to incorporate the effects loop of the
Tim then look for the correct wiring in the next chapter before wiring P6.
After wiring the potentiometers you will need to wire the footswitches. For both Tim™ as Timmy™
you will need to wire the following :
S
Tip
Sleeve
Sleeve
Output Jack
Input Jack
Cathode (short leg)
Anode (long leg)
Footswitch
Ring
R led
Tip
1 2 3

Merlin v1.1
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property of their respective owners who are in no way associated or affiliated with the author. No cooperation or endorsement
is implied.
11
When building the Tim™ you will need to add the boost switch. In the original the boost
potentiometer has a built in switch, but you can also use a footswitch with a LED to see if the boost is
engaged or not:
Anode (long leg)
Cathode (short leg)
R led
The LEDs requires a resistor (R led in the diagram) depending on the type of LED you are using. An
ultra-bright red, green or blue LED requires a 3k3 resistor, diffuse Green requires 680R. If you want to
be more exact then go here: http://www.muzique.com/schem/led.htm

Merlin v1.1
Manufacturer and product names are mentioned solely for circuit identification, and where applicable their trademarks are the
property of their respective owners who are in no way associated or affiliated with the author. No cooperation or endorsement
is implied.
12
Effects loop
The Tim™also uses an external effects loop consisting of a mono jack and a switching mono jack like
this:
The loop is connected as follows:
Return
Tip
S
Sleeve
Tip
Switch
Sleeve
Send

Merlin v1.1
Manufacturer and product names are mentioned solely for circuit identification, and where applicable their trademarks are the
property of their respective owners who are in no way associated or affiliated with the author. No cooperation or endorsement
is implied.
13
Troubleshooting
All PCB’s have been 100% factory e-tested and out of every batch I receive I build an effect to double
check, so there should not be a connection problem on the PCB itself.
The board is not working (at all), what now?
•Check if your 9V is plugged in correctly (and/or soldered correctly on the board).
•Check that you oriented the capacitors, IC’s ,transistors and diodes the right way. SMF, MKT
and ceramic capacitors as well as resistors do not need to be oriented.
•Check if you used the correct values of the components. For resistors you can look here:
http://www.diyaudioandvideo.com/Electronics/Color/
•Double and triple check your soldering! A loose or cold solder can be really bad for your
board.
•Replace the IC, it might be defective. Before doing that first unplug the 9V and wait for 5
seconds.
•Check that you have good/high grade components. A lot of Chinese sourced parts are fakes
(especially high end opamps, vintage diodes and transistors) so be careful that you source
your parts from reliable suppliers.

Merlin v1.1
Manufacturer and product names are mentioned solely for circuit identification, and where applicable their trademarks are the
property of their respective owners who are in no way associated or affiliated with the author. No cooperation or endorsement
is implied.
14
Schematic