Sunn sceptre 1971 schematic

1971 SUNN SCEPTRE with MID BOOST

D

270K/.001uF

12AU7

BRIGHT

NORMAL

270K/.001uF

47K

47K

150K 1.5K 250uF

100K 100K

0.01 470pF

V1A

1

2

3

500K

VOLUME

6

7

8

1.5K

V1B

???

in out

X Y

Located on

R/T PCB

Reverb

circuit

Tremolo

circuit

56K

270pF

.022
.022

CONTOUR

BASS

TREBLE

250K

1M

25K

220K

MID BOOST (A)

12pF

100K 100K

20M

???

C BC

270K 1.5M 12pF

6

8

7

9

6AN8

680

390pF

0.1

2

47K

1W

47K

1W

3

750pF

1K / 2W

680 / 2W

BD

6550

0.1

V3BV3A

1

1K

100K

3

5

8

E

0.1

100K

1K

5

6550

8

3

V4

4

4

V5

A

blue/wht

grn/wht

red
grn

blue

16 (yel)

8 (orn)
4 (brn)

0 (blk)

8 ohm

4 ohm

LINE

NEUTRAL

3 AMP

SLO BLO

POWER

SWITCH

with

indicator

5 VAC

330 VAC

330 VAC

6.3 VAC
to all

heaters

GZ34

6

8

2

4

V6

500 VDC

20uF @

600V

A

485 VDC

20uF @

MID BOOST (B)

B

385 VDC

6.8K / 2W 6.8K / 2W

600V

20uF 20uF 20uF

C

295 VDC

47

10K / 2W

D

260 VDC

-60 VDC

1K

BIAS

10K

50uF 50uF18K

+ +

Located on R/T PCB

E

F

+20 VDC

1K / 2W

1K / 2W

+ +

50uF 1000uF Zener ???

D C F

Reverb Input

from V1 pin 6

1.8K2.7K

TREMOLO SPEED

4.7K

+

10K

15

470K 750pF Reverb Output

REVERB

Q4

2N2923

to

V3 pin 8

Tremolo Output

to

2uF

.022470K

220K

12AU7

100K

.05

7

8 3

V2-BV2-A

47K 1.5K 1uF2.2K

4.7K

2

.005

Reverb

Input

Gibbs

Reverb Spring

Reverb
Output

10uF

Assembly

16

REVERB

FOOTSWITCH

4.7K

F

10uF

F

22K

F

.005

.022

220K

2.2M

F

1.5K

points “ X” and “Y”

680K

1uF2uF1uF

1.8K

25K25K

25K

220K

1OK

Q1

2N2923

2N2923

15

15

3.3K

Q2

10uF

TREMOLO

FOOTSWITCH

DEPTH

25K

22K

1.2K

Q3

2N2102