Mod THE PILEDRIVER Owner's manual

.1µF
400V
1
2
3
INPUT JACK OUTPUT JACK
1 3
BS170
DS G
1M 1M
5.1K
10µF 50V
100K
1 85
654
2
S
GDPWR
Guitar cable must be
plugged into the input
jack while taking voltage
measurements
DC Voltage Test Points
Use this troubleshooting supplement to help:
Measure DC voltage test points to identify major discrepancies and locate problem areas.
(Keep in mind that the voltage measurements will vary slightly from kit to kit. The voltages you measure should be in
the same ballpark, but do not expect to get the exact same value.)
Using a volt meter, connect the ground side lead of the meter to any ground point on the pedal.
One ground point would be the output jack’s ground lug. The other volt meter lead will be used to
measure DC voltage at the test points shown below.
First, plug a guitar cable into the input jack and take measurements at each test point with the
control turned all the way down (min gain) taking note of each measurement. Next, take
measurements at each test point with the control turned all the way up (max gain) and take note of
each measurement. Any major differences between the voltages listed above should indicate a
problem area.
S = 0.0 VDC
G = 1.3 VDC
D = 2.6 VDC
Measured at Maximum Gain
PWR = 9.48 VDC
S = 2.4 VDC
G = 3.4 VDC
D = 7.0 VDC
Measured at Minimum Gain
PWR = 9.49 VDC

.1µF
400V
1
2
3
INPUT JACK OUTPUT JACK
1 3
BS170
DS G
1M 1M
5.1K
10µF 50V
100K
1 85
654
2
1
Guitar must be plugged
into the input jack while
taking voltage
measurements
AC Voltage (Signal) Test Points
Connect your guitar to the input jack and take AC voltage measurements at each test point with
the control turned all the way up. At each test point, the AC voltage should increase dramatically
each time you strum the guitar. (No strum = 0.0 VAC, Hard strum = anywhere from 10 mV to 3 V).
Turn all the
way up
Make sure
the pedal is
not in bypass
mode.
2
345
6

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“The PileDriver” (K-920)
Schematic
10µ
+
-
9 VDC
Battery
1M
1M
5KL
.1µ
Output
Input
Foot
Switch
(A)
Foot
Switch
(B)
23
1
6
5
4
0.0V
@ 9.48 VDC
0.5 mADC
BS170
N-Channel
MOSFET
G S
D
1N4005
G
D
S
5.1K
100K
+
BS170
DPDT Foot Switch
2 31
6
54
1N4005
@ 9.49 VDC
1.4 mADC
2.4V
2.6V
1.3V
7.0V
3.4V
-0.3VDC
*
BOLD = DC measurement at maximum gain
PLAIN = DC measurement at minimum gain
*Diodes are there to protect the MOSFET from
static and accidental reverse polarity.
*100 mV
AC
100 mV
AC 70 mV
AC
2.5 VAC
2.5 VAC 2.5 VAC
*AC voltages were measured while strumming
an open E chord on a Mexican strat in neck
pickup position with volume and tone controls at
max.

.1µF
400V
1
2
3
INPUT JACK OUTPUT JACK
1 3
BS170
DS G
1M 1M
5.1K
10µF 50V
100K
1 85
654
2
Voltage Gain Test Points
Make sure
the pedal is
not in bypass
mode.
V(in)
V(out)
R(s)
R(s) = Resistance from
Source to Ground. V(in) V(out)
4.86K
2.42K
1.22K
0K
.16 VAC
.16 VAC
.16 VAC
.16 VAC
.16 VAC
.24 VAC
.45 VAC
2.60 VAC
Unplug from the input jack
to disconnect power when
measuring resistance.