Lithium Grim Snail Gear Instruction Manual

Snail Gear
Building instructions
V1.1

Snail Gear v1.1
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Table of contents
Components .......................................................................................................................................3
PCB layout ..........................................................................................................................................4
General guideline for components ......................................................................................................5
General building tips...........................................................................................................................5
Modifications......................................................................................................................................6
Biasing................................................................................................................................................7
Off board wiring..................................................................................................................................7
Troubleshooting .................................................................................................................................8
Schematic ...........................................................................................................................................9
Read this entire manual thoroughly before you start to building the effect! Especially the
Modification and Biasing part. Decide before building the effect which mods you want to try so that
you do not need to desolder parts later.
Last update: 26-02-2017

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Components
Name
Value
Comment
Name
Value
Comment
C1
47n
MKT
R1
1k
C2
22n
MKT
R2
470k
C3
1u
Electrolyte
R3
10k
C4
47u
Electrolyte
R4
22k
C5
1u
Electrolyte
R5
3k3
C6
470n
Electrolyte!
R6
470k
C7
33n
MKT
R7
47k
C8
1u
Electrolyte
R8
1M
C9
22n
MKT
R9
1M
C10
1u
Electrolyte
R10
1M
C11
10u
Electrolyte
R11
10k
C12
1n
MKT
R12
1k
C13
1u
Electrolyte
R13
100k
C14
1u
Electrolyte
R14
470R
C15
47n
MKT
R15
220k
C16
10u
Electrolyte
R16
390R
C17
33u
Electrolyte
R17
1M
C18
10u
Electrolyte
R18
1k
D1
Zener 5,6V
R19
390k
D2
1n4148
R20
4k7
D3
1n4148
R21
4k7
D4
1n4148
R22
100k
IC1
TL071
R23
100k
Q1
BC549C
R24
10k
Q2
2SK30A
2N5457 use extra D pad
R25
22k
Q3
BC549C
R26
22k
Q4
BC549C
R27
1M
Q5
BC549C
Match with Q6
VR1
A100k
Sensitivity
Q6
BC549C
Match with Q5
VR2
B25k
Attack
VR3
B10k
BIAS Trim pot

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PCB layout

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General guideline for components
Capacitors: All values under 1nF should be ceramic disks or silver mica. From 1nF up to 1uF
should be SMF (Panasonic stacked metal film) or MKT (Metallized plastic polyester) and
values over 1uF use electrolyte caps 16V+ rated and watch out for polarity.
Resistors: use 1% metal film for the best results.
Socket the IC’s. This way you can easily mod them or replace them if they break.
Orientation of the transistors: the white stripe on the PCB indicates where the flat side of the
transistor should be except for Q2, that one the bold side is facing the white stripe.
General building tips
Before you start you will need to make sure that you match the Hfe of Q5 and Q6 for the best result.
Matching is done by using a Digital Multi Meter (DMM). Get them as close together as possible. You
can use any BC549A/B/C or even BC550A/B/C for Q1,Q3,Q4,Q5 and Q6. For Q2 you can only use a
2SK30A or a 2N5457, but the pinout is different so you’ll need to use the extra D pad for the 2N5457:
The original Attack pot is B20K. You can easily use the readily available B25K or you can place a 100K
resistor between pins 1 and 3 to lower the B25K to B20K.
B25K
100k
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
transistors than 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.
Start by soldering D2-D4 and then solder the resistors (but not yet VR3) and then D1.
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!
Next, solder the IC sockets, and transistors or if desired the transistor sockets (only if you want to try
different transistors!) then the VR3 and MKT. Lastly solder the electrolyte capacitors.
Place the IC (and transistors) and you are almost ready to rock. The flat sides of the transistor are
indicated by the thick white line.
X
X

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Besides the components mentioned in the table on the page 3, 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.
1x 3PDT footswitch (9 pins). I also sell an easy off board circuit for true bypass.
2,1mm DC jack (isolated).
9v battery clip (optional).
22 gage stranded hook-up wire.
1 x 3mm LED (and if needed a LED holder to mount it in the enclosure)
Hammond 1590B case (or similar) in your favorite color. A Hammond 1590BB will give you
more room to build especially when using the swell mod.
Modifications
Swell MOD. You can extend the swell time by changing C6 to a higher value. Especially for
this mod the SW1 is added to the board. If you do not decide to use the mod then leave out
the SW1. If you do want to use the mod, I suggest using a DP3T (ON/OFF/ON) switch with the
4.7uF on one side and eg. a 22uF on the other side. Experiment with different values before
you decide to do the mod. You could even make a rotary switch with even more values! The
lower you set the Attack, the longer the swell takes. In combination with a 22uF (C6) it is
about 0,5 seconds.
22uF
+
-
4.7uF
+
-
The original uses a LM741 instead of a TL071.

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Biasing
The most important part of this build is the biasing. If your effect is inaudible at low attack settings
then it is not biased correctly. Biasing can be done by ear, but can be difficult, so take your time.
1. Turn Attack to 0 (=fully counterclockwise) and Sensitivity to 5 (=halfway/12 o’clock) and VR3
to 10 (=fully clockwise)
2. Turn the VR3 until you hear the effect swell correct and without volume loss.
NB the Sensitivity pot is used to adapt the effect to the amount of input the effect gets (like an input
boost). If you use a booster/fuzz in front of the effect, you will need to lower the Sensitivity to get
the optimal result.
Off board wiring
S
Tip
Sleeve
Sleeve
Output Jack
Input Jack
Cathode (short leg)
Anode (long leg)
Footswitch
Ring
R led
Tip
The LEDs requires a resistor (R led in the diagram) depending on the
type of LED you are using. To be safe use a 3k3 or 4k7 resistor. If
you want to be more exact then go here:
http://www.muzique.com/schem/led.htm
Blue = pin 1
White = pin 2
Yellow = pin 3

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Troubleshooting
All PCB’s have been 100% factory e-tested and out of every batch I receive I build a 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
capacitors and 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’s and transistors, one might be defective. Before doing that first unplug the 9V
and wait 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.

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Schematic