5

5

4

4

3

3

2

2

1

1

D

D

C

C

B

B

A

A

1

1

SOLDANO X88R

C

1

1

Friday, July 12, 2002

Title

Size

Document Number

Rev

Date:

Sheet

of

E

C

C

B

E

B

D

A

A

VR9
25K

VR3
1M

VR14
25K

J1
IN

1

2
4

J2
OUT

1

2
4

R14
220K

SW3
BRIGHT CLEAN

R35
39K

R9
470K

VR5
500K

R1
1M

U5-2

12AX7

6

7

8

VR1
500K

VR15
1M

C17
0.022uF

C11
0.022uF

R22
100K

C24
0.022uF

R39
330K

R46
82K

U3-1

12AX7

1

2

3

R7
100K

R28
1.8K

C3
0.0022

OI4A

VTL5C1

3

4

VR13
1M

R42
47K

VR4
25K

VR8
1M

R10
1M

C18
0.022uF

R4
1.8K

C12
0.022uF

R23
2.2K

R34
470K

U2-2

12AX7

6

7

8

U5-1

12AX7

1

2

3

C19
470pF

R47
2.2K

SW1
BRIGHT LEAD

C5
1uF

R27
100K

R41
2.2K

R25
330K

C4
0.001

OI5A

VTL5C1

3

4

C7
0.001

U3-2

12AX7

6

7

8

C20
0.022uF

R32
680K

C15
0.1uF

R43
470K

C13
470pF

R3
220K

R15
100K

C14
0.022uF

R18
47K

U1-1

12AX7

1

2

3

R24
680K

C8

0.022uF

C23
0.022uF

U6-1

12AX7

1

2

3

R12
39K

C16
470pF

VR12
250K

C6
0.022uF

R11
100K

R19
330K

R5
470K

R26
220K

R31
330K

C2
0.047uF

R38
2.2M

R16
1.8K

R44
220K

R21
470K

R36
100K

R37
2.2K

U1-2

12AX7

6

7

8

R30
47K

VR2

250K

C1
1uF

OI1A

VTL5C1

3

4

VR11
500K

C22
470pF

U6-2

12AX7

6

7

8

R13
330K

R20
680K

R29
100K

R2
68K

R40
100K

R6
470K

VR10
500K

C10
470pF

C21
120p

R33
470K

C9
1uF

R45
2.2K

C25
0.1uF

U4-1

12AX7

1

2

3

VR7
250K

VR6
500K

U4-2

12AX7

6

7

8

R17
100K

R8
1.8K

U2-1

12AX7

1

2

3

OI3A
VTL5C1

3

4

SW2
BRIGHT CRUNCH

OI2A

VTL5C1

3

4

5

5

4

4

3

3

2

2

1

1

D

D

C

C

B

B

A

A

SWITCH/INDICATION
POWER SUPPLY

Filament reference supply

1N4007

To minimize inductive coupling wire filaments in this order. F1 is the filament of V1

LS1-LS3 - HASCO HS212 or similar

Footswitch capabilities can easily be added to this schematic by
putting a SPST switch before SW2 so that it could be turned off when
footswitch is enabled and wiring the gates of Q1-Q3 to a footswitch
connector. Alternatively a 4 position rotary channel switch can be
used with one position left unwired.

+432V

+5V

All voltages for switching circuits are specified relative to their
floating ground. This floating ground should NOT be connected
to the signal ground.

D3-D6 MUR1100E

D11-D13 1N4148

D14-D16 are red LEDs w 4V voltage
drop and 25mA current rating

D1, D2 1N5368B

D1 and D2 depend on how much voltage the transformer is
putting out and might not even be necessary The voltage
measurement on C1 should be less than its voltage rating by
around 18-20V. This measurement is taken without connecting
the B+ supplies to tubes, but with filaments wired and
connected.

D3-D6 can be replaced with similar 1000V fast recovery
rectifiers

2

1

X88R POWER SUPPLY, SWITCHING AND INDICATION

C

1

1

Tuesday, August 20, 2002

Title

Size

Document Number

Rev

Date:

Sheet

of

Vref

D

C

Vref

B

E

A

D1

F3

SW1
POWER

LS1

3

4

5

6

8

7

1
2

OI4A
TLP227

R16
180

F1
1A SLO BLO

+

C7
22uF 450V

OI3A
TLP227

R4
100K

R11
47K

7805

U1

LS2

3

4

5

6

8

7

1
2

OI2A
VTL5C1

D11

+

C8

4700uF 16V

R5
10K 2W

R14
47K

F2

+

C1
47uF 450V

R8
10K 2W

-

+

D3-D6

R19
390

R18
47K

R17
43

R6
10K 2W

LS3

3

4

5

6

8

7

1
2

F6

D12

SW2

CHANNEL

J1
AC PWR

1

2

3

R2
1K 2W

F1

D15
CRUNCH

150VAC

150VAC

6.3VAC

T1

Hammond 269BX

1

5

6

4

8
9

10

R21
43

Q2
2N7000

+

C4
22uF 450V

R9
100

+

C3

100uF/100V

F5

Q3
2N7000

+

C6
22uF 450V

D13

-

+

D7-D10

D16
LEAD

R10
100

+

C2
47uF 450V

R20
180

R3
1M

R7
10K 2W

D2

F4

R1
150K 2W

+

C5
22uF 450V

+

C9

4700uF 16V

R15
390

Q1
2N7000

OI1A
VTL5C1

R13
43

OI5A
TLP227

D14
CLEAN

R12
390

A

A

B

B

C

C

D

D

E

E

4

4

3

3

2

2

1

1

Initial design: Randall Aiken

R E V :

CHANNEL1

CHANNEL2

CHANNEL3

TO AMPLIFIER SWITCHING LOGIC

(1) ALL SWITCHES ARE MOMENTARY CONTACT SPST

CHANNEL1

CHANNEL2

CHANNEL3

N O TES:

(2) VCC SUPPLY CAN RANGE FROM 5V TO 15V

FOOTSWITCHES

R E SET LOGIC

SWITCH LATCHES

CHANNEL INDICATORS

(SELECTED CHANNEL HIGH,
ALL OTHERS LOW)

(3) OUTPUT CONTROL SIGNALS ARE CMOS-COMPATIBLE LEVELS
(CAN SOURCE/SINK AROUND 0.5mA MAX AT 5V).

5-PIN DIN (MIDI) CABLE
R E COMMENDED

TYPICAL RELAY INTERFACE CIRCUIT

(5) ALL PARTS AVAILABLE FROM DIGI-KEY (1-800-DIGIKEY)

(4) LED CURRENT LIMITING RESISTOR VALUE IS FOR 5V. IT MAY
NEED TO BE LARGER FOR HIGHER VCC VOLTAGES

P O W E R - U P RESET

A

AIKEN AMPLIFICATION

1 0 8 3 6 C L E M S O N B L V D . . # 2 0 8
S E N E C A , S C 2 9 678

T E L : 8 6 4 - 6 2 4 - 9 7 9 6

F A X : 8 6 4 - 6 2 4 - 9 797

1

3-CHANNEL FOOTSWITCH CONTROLLER

Tuesday, June 22, 1999

Title

Size

Document Number

R e v

Date:

Sheet of

C H A N N E L 2
C H A N N E L 3

C H A N N E L 1

C H A N N E L 1

V C C

V C C

V C C

V C C

V C C

V C C

V C C

+ 5 V

V C C

J1

C O N 5

1
2
3
4
5

D 1

G R E E N L E D

2

1

R 1

33 0

1

2

D 2

Y E L L O W L E D

2

1

D 3

R E D L E D

2

1

C ?

0.1uF

1

2

D 4

1 N 4 1 4 8

2

1

D ?

1 N 4 1 4 8

2

1

U 1

C D 4 0 4 4

4
3

6
7

1 2
1 1

1 4
1 5

5

1 3

9

1 0

1

16

8

2

R 0
S 0

R 1
S 1

R 2
S 2

R 3
S 3

E N

Q 0

Q 1

Q 2

Q 3

VDD

VSS N C

U 2 D

C D 4 0 8 1

12

13

1 1

U 2 B

C D 4 0 8 1

5

6

4

U 2 A

C D 4 0 8 1

1

2

3

U 2 C

C D 4 0 8 1

8

9

1 0

S 1

S W S P S T

1

2

S 2

S W S P S T

1

2

S 3

S W S P S T

1

2

R 2

4 7 K

1

2

R 3

4 7 K

1

2

R 4

4 7 K

1

2

Q 1
2 N 7 0 0 0

2

3

1

Q 2
2 N 7 0 0 0

2

3

1

Q 3
2 N 7 0 0 0

2

3

1

Q 4
2 N 7 0 0 0

2

3

1

K 1

G 5 V - 2 - H - D C 5

4

6

8

1 3

11

9

1

1 6