Dr. Quack

effect pedal project by AMZ/EHX

Here's the Dr. Quack effect pedal project from AMZ/EHX.

This project has been described using terms like filter, stripboard, vero, and wah and is reportedly verified, meaning many hobbyists have already completed this project and verify that the instructions are without issue.

Beyond the specs and details found on this page, you'll want to check out these stripboard resources too.

Project Resources

Parts List

  • C1
    50n
  • C2
    50n
  • C3
    10u
  • C4
    10u
  • C5
    5n
  • C6
    1n
  • C7
    50n
  • C8
    5n
  • C9
    10n
  • C10
    10u
  • D1
    LED
  • D2
    LED
  • D3
    1N914
  • P1
    100k Sens
  • P2
    25k Range
  • Q1
    JRC4558
  • Q1 (Alt)
    NE5532
  • Q1 (Alt)
    TL072
  • Q1 (Alt)
    Opamp Dual
  • R1
    1M
  • R2
    47k
  • R3
    10k
  • R4
    2M2
  • R5
    100R
  • R6
    1M
  • R7
    10k
  • R8
    22k
  • R9
    470k
  • R10
    47k
  • R11
    470k
  • R12
    47k
  • R13
    47R
  • R14
    470k
  • R15
    47k
  • R16
    47k
  • S1
    DPDT
  • T1
    2N5457
  • T2
    BC239C
  • U1
    9V

Similar transistors & Potential Alternatives

Can't find an exact match for the recommended transistors in this project within your stash? Or maybe you just feel like experimenting. Use these tables below to get started finding a suitable or otherwise interesting transistor substitution.

There may be 2 alternatives for the 2N5457 mentioned above in the parts list for this project. These suggestions were derived by considering the original component's FETType, CntlChType, Vgs, Vds, and Id values and finding comparables in our database. These alternatives are suggestions for further exploration (fun!) and have not been tested in the context of this project. You can also to suit your preferences.

2N5457
more info
CntlChType
N
channel
FETType
JFET
Id
0.005
A
Pd
0.625
W
Tj
150
°C
Vds
25
V
Vgs
2.5
V
2N5953
more info
CntlChType
N
channel
FETType
JFET
Id
0.005
A
Pd
0.36
W
Tj
150
°C
Vds
30
V
Vgs
2.5
V

There may be 37 alternatives for the BC239C mentioned above in the parts list for this project. These suggestions were derived by considering the original component's hFE, Pol, Ic, Vcb, and Vce values and finding comparables in our database. These alternatives are suggestions for further exploration (fun!) and have not been tested in the context of this project. The first 25 alternatives are shown below in alphabetical order by partnumber. See the to suit your preferences.

BC239C
more info
Cc
5
pF
ft
150
MHz
hFE
420
β
Ic
0.1
A
Pc
0.3
W
Pol
NPN
Tj
125
°C
TranMat
Si
Vcb
30
V
Vce
20
V
Veb
5
V
A748C
more info
Cc
5
pF
ft
150
MHz
hFE
420
β
Ic
0.2
A
Pc
0.25
W
Pol
NPN
Tj
125
°C
TranMat
Si
Vcb
30
V
Vce
20
V
Veb
5
V
A749C
more info
Cc
5
pF
ft
150
MHz
hFE
420
β
Ic
0.2
A
Pc
0.25
W
Pol
NPN
Tj
125
°C
TranMat
Si
Vcb
30
V
Vce
20
V
Veb
5
V
BC108C
more info
Cc
5
pF
ft
150
MHz
hFE
420
β
Ic
0.1
A
Pc
0.3
W
Pol
NPN
Tj
175
°C
TranMat
Si
Vcb
30
V
Vce
20
V
Veb
5
V
BC108CP
more info
Cc
5
pF
ft
150
MHz
hFE
420
β
Ic
0.1
A
Pc
0.3
W
Pol
NPN
Tj
175
°C
TranMat
Si
Vcb
30
V
Vce
20
V
Veb
5
V
BC109C
more info
Cc
5
pF
ft
150
MHz
hFE
420
β
Ic
0.1
A
Pc
0.3
W
Pol
NPN
Tj
175
°C
TranMat
Si
Vcb
30
V
Vce
20
V
Veb
5
V
BC109CP
more info
Cc
5
pF
ft
150
MHz
hFE
420
β
Ic
0.1
A
Pc
0.3
W
Pol
NPN
Tj
175
°C
TranMat
Si
Vcb
30
V
Vce
20
V
Veb
5
V
BC148C
more info
Cc
5
pF
ft
150
MHz
hFE
420
β
Ic
0.2
A
Pc
0.25
W
Pol
NPN
Tj
125
°C
TranMat
Si
Vcb
30
V
Vce
20
V
Veb
5
V
BC149C
more info
Cc
5
pF
ft
150
MHz
hFE
420
β
Ic
0.2
A
Pc
0.25
W
Pol
NPN
Tj
125
°C
TranMat
Si
Vcb
30
V
Vce
20
V
Veb
5
V
BC238C
more info
Cc
5
pF
ft
150
MHz
hFE
420
β
Ic
0.1
A
Pc
0.3
W
Pol
NPN
Tj
125
°C
TranMat
Si
Vcb
30
V
Vce
20
V
Veb
5
V
BC238CP
more info
Cc
5
pF
ft
150
MHz
hFE
420
β
Ic
0.1
A
Pc
0.3
W
Pol
NPN
Tj
125
°C
TranMat
Si
Vcb
30
V
Vce
20
V
Veb
5
V
BC239CP
more info
Cc
5
pF
ft
150
MHz
hFE
420
β
Ic
0.1
A
Pc
0.3
W
Pol
NPN
Tj
125
°C
TranMat
Si
Vcb
30
V
Vce
20
V
Veb
5
V
BC408C
more info
Cc
5
pF
ft
150
MHz
hFE
420
β
Ic
0.1
A
Pc
0.25
W
Pol
NPN
Tj
125
°C
TranMat
Si
Vcb
30
V
Vce
20
V
Veb
5
V
BC409C
more info
Cc
5
pF
ft
150
MHz
hFE
420
β
Ic
0.1
A
Pc
0.25
W
Pol
NPN
Tj
125
°C
TranMat
Si
Vcb
30
V
Vce
20
V
Veb
5
V
BC438C
more info
Cc
3.5
pF
ft
200
MHz
hFE
420
β
Ic
0.1
A
Pc
0.22
W
Pol
NPN
Tj
125
°C
TranMat
Si
Vcb
30
V
Vce
20
V
Veb
6
V
BC439C
more info
Cc
3.5
pF
ft
200
MHz
hFE
420
β
Ic
0.1
A
Pc
0.22
W
Pol
NPN
Tj
125
°C
TranMat
Si
Vcb
30
V
Vce
20
V
Veb
6
V
BCF29C
more info
ft
165
MHz
hFE
420
β
Ic
0.2
A
Pc
0.25
W
Pol
NPN
Tj
125
°C
TranMat
Si
Vcb
30
V
Vce
20
V
Veb
5
V
BCF92C
more info
ft
165
MHz
hFE
420
β
Ic
0.2
A
Pc
0.25
W
Pol
NPN
Tj
125
°C
TranMat
Si
Vcb
30
V
Vce
20
V
Veb
5
V
BCW33
more info
Cc
4
pF
ft
300
MHz
hFE
420
β
Ic
0.1
A
Pc
0.35
W
Pol
NPN
Tj
150
°C
TranMat
Si
Vcb
30
V
Vce
20
V
Veb
5
V
BCW33LT1
more info
Cc
4
pF
ft
300
MHz
hFE
420
β
Ic
0.1
A
Pc
0.3
W
Pol
NPN
Tj
150
°C
TranMat
Si
Vcb
30
V
Vce
20
V
Veb
5
V
BCW33LT3
more info
Cc
4
pF
ft
300
MHz
hFE
420
β
Ic
0.1
A
Pc
0.3
W
Pol
NPN
Tj
150
°C
TranMat
Si
Vcb
30
V
Vce
20
V
Veb
5
V
BCW33R
more info
Cc
4
pF
ft
300
MHz
hFE
420
β
Ic
0.1
A
Pc
0.35
W
Pol
NPN
Tj
150
°C
TranMat
Si
Vcb
30
V
Vce
20
V
Veb
5
V
BCW48C
more info
Cc
4
pF
ft
150
MHz
hFE
400
β
Ic
0.1
A
Pc
0.15
W
Pol
NPN
Tj
125
°C
TranMat
Si
Vcb
30
V
Vce
20
V
Veb
5
V
BCW49C
more info
Cc
4
pF
ft
150
MHz
hFE
400
β
Ic
0.1
A
Pc
0.15
W
Pol
NPN
Tj
125
°C
TranMat
Si
Vcb
30
V
Vce
20
V
Veb
5
V
BFR68C
more info
Cc
4
pF
hFE
420
β
Ic
0.15
A
Pc
0.1
W
Pol
NPN
Tj
125
°C
TranMat
Si
Vcb
30
V
Vce
20
V
Veb
5
V