Hoffman Princeton Reverb Quick start guide

Intensity
250kl
Reverb
100kl
Bass
250ka
100k
1
2
3
4
5
6
7
8
9
Volume
1ma
1
2
3
4
5 6
7
8
9
12a
T
S
G
Treble
250ka
1m
V2
33k
V1-2
Ground Buss
Hoffman Amplifiers Princeton Reverb
2.7k
1n4007
DBA C
www.hoffmanamps.com
V1
1
2
3
4
5
6
7
8
9
V3 V5
4
5
6
7
8
1
2
3
1.5k
4
5
6
7
8
1
2
3
1.5k
Speed
3mra
FeedBack Bias Range
Bias Tap
250p
.1
.047
+
22/50v
1.5k
+
22/50v
1.5k
100k
.022
500p
3.3m
10p
+
22/50v
1.5k
.0033
+
22/50v
1.5k
100k
220k 220k
100k/3w
1k/3w
100k
1 ohm
470/3w 470/3w
1 ohm
22k
100k
V1-7
1
2
3
4
5
6
7
8
9
V4
022921
Reverb send
To Tank Input 220k
Reverb Return to Tank Output and Foot switch jack
Vibrato Foot switch jack
RG174
Shielded
To Power
Transformer
Ground Lug
V6
470k
2.2k/3w
+
22/50v
100k
47
.022
1m
.01
.01
.022
1m
1m .022
.1
220k
.1 56k
1m
56k1k
.1
6.8k
18k/3w
+
22/50v
3.3k
18k/3w
+
47/100v
10kl
1m
OT OT
3.125" x 11.5"

FUSE
4
5
6
7
8
1
2
3
Lamp
6.3 vac
5 vac
Power Cord
White
Green
Black
To heaters
To heaters
Speaker Jack
Power
Transformer
Output Transformer
1 Amp slo-blo
On/Off
Switch
Standby
Bias Tap
A
D BC
+ + + + + +
20uf 500v
+ +
40uf 500v
Pin 3
Pin 3
FeedBack
Power Transformer
Ground Lug
Board Connections
T
S
G
+
-
Optional
Clickable Links
EL34 World Tube amp Library page
Hoffman Amplifiers parts catalog
Hoffman Layout diagram hookup information www.hoffmanamps.com
Hoffman princeton Reverb
Board A
Board A
20uf 500v
20uf 500v

R26
3.3M
C13
.022 C14 10p
V3-B
R27
100k C15
.022
R32
2.2K
3W
C18
22uf
R31
1M
C17
500p Reverb Tank
4AB3C1B
C20
22uf
R35
1.5k
R33
220k
R34
100k C19
.0033 REVERB
R36
100kL
R37
470k
REVERB
FOOTSWITCH
6
161
2 7
3 8
2
3
7
8
V3-A
V2-BV2-A
R28
1.5k C16
22uf
To PHASE
INVERTER
R20
250ka
C8
250p
C9
.1
C10
.047
R19
100k
R18
1.5k
R17
100k
V1-A
C7
22uf
R21
250ka
TREBLE R23
1ma
VOLUME
BASS
R24
100k
R25
1.5k C12
22uf
1
2
3
6
7
8
V1-B
PREAMP and REVERB
12AT7
REVERB
DRIVER
12AX7
REVERB
RECOVERY
R2
68k
R3
68k
R1
1m
HI
(1)
LO
(2)
Dual Input Jacks
J1 –J2
R2
33k
R1
1m
J1
12AX7
T4
022921
J7 J8
J9
B
DD D
D
Hoffman Princeton Reverb
www.hoffmanamps.com
Reverb channel
SW4
Thanks to Sluckey on the Hoffmamps forum for creating the original schematic
R22
6.8k
R29
47
Feedback
+++
+ +

6.3 VAC
5 VAC
R69
18k / 3w R70
18k / 3w
68
2
4
R64
250kl
POWER AMP, TREMOLO
and POWER SUPPLY
C15
.022
R43
1m R41
1k
C25
.1
R50
1.5k
R48
220k
C24
.1
R47
220k
R40
56k R49
1.5k
R51
2.7k
R52
1Ω
R53
1Ω
R54
470/3w
R55
470/3w
SPEAKERS
6
7
8
5
8
3
4
8
5
3
4
V4-B
V6
V7
From
PREAMP
V7
5U4G
R56
3mra D1
1N4007
R65
10kl
R66
22k R67
100k/3 watt
C32
47uf
3
2
1
V4-A
BIAS SUPPLY
C30
.1
C31
.022
R63
1m
R58
220k
R59
1M
R61
3.3k C29
22uf
R60
1M
C28
.01
C27
.01
C26
.022
R57
100k
TREMOLO
FOOT
SWITCH
12AX7
TREMOLO
OSCILLATOR
12AX7
PHASE
INVERTER
POWER
AMPLIFIER
C
B
B
A
ABD
SPEED INTENSITY BIAS
BIAS RANGE
R71
100
R72
100
Lamp
or
LED
NEUTRAL
LINE
GROUND
1 amp
SLO BLO SW1
SW2
SW5
Heaters
Heaters
C34
40uf C35 20uf C36 20uf C37 20uf
T1
T2
www.hoffmanamps.com
J5
J10
Thanks to Sluckey on the Hoffmamps forum for creating the original schematic
Feedback
R42
56k
Hoffman Princeton Reverb
Optional
Standby
switch
R68
1k / 3w
++
++ + +
Multi Section Filter Cap
40x20x20x20 / 475v
D

DBA C
10kl
Hoffman Amplifiers Princeton Reverb www.hoffmanamps.com