7/23/2019 EH Small Stone

1/2

0

1

1

2

2

3

0 1 1 2

3

2

6IC57

45

1M100 47k 33uF

4k7

15k

1k

1k8.1

27kON

22k+V

+V

.1

3

26

IC17

4

5

2k

.0068

30k

1k

Vbias

27k

47k

3

26

IC27

4

5

2k

.0068

27k

1k

Vbias

27k

47k

3

26

IC47

4

5

2k

.0068

27k

1k

Vbias

27k10k

47k

3

26

IC37

4

5

2k

.0068

27k

1k

Vbias

27k10k

47k

270k

4k7

ON

3k3

27k

10k 10k

+V

+

9vAC

ADAPTOR

INPUT

100k

10k

.0068

4k7

470k

Vbias

4k7

10k

15k

33uF

Vbias

10uFOUTPUT

.1

470k

27k

30k

470

+V

LFO

LFO

2k

This circuit works like a Small Stone. It uses the CA3080 OTA instead of the obsolete CA3094. Whentrue bypass is used, theres a volume drop when effect is on. Off board components except for thepotentiometers are not shown on the layout. Small Stone is a registered trademark owned by EH.

PiedritaRev.6.Nov.28.2004

+V

7k5

27k

1M R21

F

P

2003

F

P

3

PIEDRITA

P

I

E

D

R

I

T

A

IC1

I

C

IC

2

I

IC3

I

C

3

IC4

I

C

4

IC5

I

C

5

Q11 Q22

Q33

Q44

Q55

Q66

Q77

Q88

Q99

Q1 010

Q1 111

Q1 212

Q1 313

Q1414

INNGNDND

OUTUT

+9V9V

-

+ O

+V

-V

10k

R33

27k

R32

27k R28

1kR

29

10k

R1

1

k

R40

4k7

R12

3k3

R11

27k

R34

1k

R36

10k R31

470k R5

27k

R10

27k R30

1k

R27

27k

R13

10k R6

30k R25

-

+ O

+V

-V

4k7 R7

470k R14

4k7 R15

4k7 R42

30k R8

27k R38

27k R37

10k R39

27k

R41

1k8

R20

15k R17

22k

R16

1k R187k5

R23

27K

R22

-

+O

+V

-V

-

+O

+V

-V

C7

+33uFC1 C5

C8

+

33uFC12

C9

270k

R9

-

+ O

+V

-V

C2

+

10uFC3

27k

R19

100k

R4

15k R3

100 R24

C4

470

R2

2KR

X

47k

2k

47k

47k

47k

2k

2k

2k

47k

10k

R35

C6

C10

+

47uFCb

Ca

47uF

.1

Layoutandpresentation

byFranciscoPea2001-200

.

Allrightsreserved.

Autho

rizationforpersonaluseonly,

anycommercialuseisfo

rbidden.

Permissionforposting/servinglimitedto

4

Q1

Q11

Q2

Q12

Q3

Q13

Q4

Q14

Q5Q6

Q7Q8

Q9Q10

7/23/2019 EH Small Stone

2/2

C6

3

26

IC17

4

5

2k

C4

R25

R27

Vbias

R30

47k

3

26

IC27

4

5

2k

C5

R28

R29

Vbias

R32

47k

3

26

IC47

4

5

2k

C8

R37

R36

Vbias

R34R35

47k

3

26

IC37

4

5

2k

C9

R41

R40

Vbias

R38R39

47k

R9

3

2

6IC57

45

R21R24 47k C12

R15

R12

R17

R18

R20C10

R19

ON

ON

R11

R16

R10

R31 R33

+V

+V

+V

+

9vAC

ADAPTOR

INPUT

R4

R6

C2

R7

R5

Vbias

R42

R1

R3

C1 Cb

Vbias

C3OUTPUT

C7

R14

R13

R8

R2

+V

LFO

LFO

2k

+V

R23

R22

ResistorsR1 - 10kR2 - 470ohmR3 - 15kR4 - 100kR5 - 470kR6 - 10k

R7 - 4k7R8 - 30kR9 - 270kR10 - 27kR11 - 3k3R12 - 4k7R13 - 27kR14 - 470kR15 - 4k7R16 - 22kR17 - 15kR18 - 1kR19 - 27kR20 - 1k8R21 - 1M potR22 - 27kR23 - 7k5R24 - 100R25 - 30k

R26 -R27 - 1kR28 - 27kR29 - 1kR30 - 27kR31 - 10kR32 - 27k

R33 - 10kR34 - 27kR35 - 10kR36 - 1kR37 - 27kR38 - 27kR39 - 10kR40 - 1kR41 - 27kR42 - 4k7

RX5 - 2k

RY5 - 47k

CapacitorsC1 - 33 FC2 - 0.0068 FC3 - 10 FC4 - 0.0068 FC5 - 0.0068 FC6 - 0.1 F

C7 - 0.1 FC8 - 0.0068 FC9 - 0.0068 FC10 - 0.1 FC11 -C12 - 33 FCa - 0.1 FCb - 47 F

TransistorsQ1 - 2N5088

2

ICs5 - CA3080

Q - 2N5087Q3 - 2N5088Q4 - 2N5088Q5 - 2N5088Q6 - 2N5088

Q7 - 2N5088Q8 - 2N5088Q9 - 2N5088Q10 - 2N5088Q11 - 2N5087Q12 - 2N5087Q13 - 2N5088Q14 - 2N5088

Parts List

Q11 Q22

Q33

Q44

Q55

Q66

Q77

Q88

Q99

Q1 010

Q1 111

Q1 212

Q1 313

Q1 414

INN GNDND

OUTUT

+9V9V

RA TEA TE

+ C1C

+

C1212

+

C33

R11

R

R

10

R

R33

R

3

3

R32

R

3

2

R2 828

R2

9

R

2

9

R1R

R12

R

2

R36

R

3

6

R3 131

R55

R3030

R27

R

2

7

R13

R

3

R66

R2 525

R77

R1 414

R1515

R4242

R88

R23

R

2

3

R22

R

2

2

C77

C5C

5

C22

C4C

4

R2R

2

RXR

X

IC1

I

C

IC

2

I

IC5

I

C

5

R34

R

3

4

R40

R

4

R3838

R3737

R3939

R

41

R

4

R20

R

2

R1 717

R16

R

6

R1 818

C8C

8

C9C

9

R9R

9

R19

R

9

R4R

4

R33

R2 424

R35

R

3

5

C6C

6

C10

C

IC3

I

C

3

+

Cbb

IC4

I

C

4

.1

Q1

Q11

Q2

Q12

Q3

Q13

Q4

Q14

Q5Q6

Q7Q8

Q9Q10