Neve 1081 User Guide

1081 Channel Amplifier

Including 3U and 7U Rack Options

User Guide

527-230

Issue 3

© 2000 AMS Neve plc own the copyright of all
information and drawings contained in this manual which
are not to be copied or reproduced by any means or
disclosed in part or whole to any third party without
written permission.

As part of our policy of continual product improvement,
we reserve the right to alter specifications without notice
but with due regard to all current legislation.

Disclaimer: The information in this manual has been
carefully checked and is believed to be accurate at the
time of publication. However, no responsibilty is taken by
us for inaccuracies, errors or omissions nor any liability
assumed for any loss or damage resulting either directly or
indirectly from use of the information contained within it.

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LANCS BB11 5UB  ENGLAND

TELEPHONE: [phone]  FAX: [phone]

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TELEPHONE: [phone]  FAX: [phone]

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TEL: [phone]  FAX: [phone]

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http://www.ams-neve.com

1081 Channel Amplifier

Contents

Introduction 1

Installation 1

Dimensions 2

Power Requirements 3

Phantom Power 4

Output Level Control 4

Amplifier Controls 5

EMI Filter Components 6

Rear Panel Views 7

Connector Details 8

Connector Details Continued 9

Specifications 10

Service Information 11

1081 Recall Sheet - Horizontal Module 12

1081 Recall Sheet - Vertical Module 13

User Guide Issue 3 Page i

1081 Channel Amplifier Introduction

Introduction

The 1081 channel amplifier was first produced in 1972 to provide the mic/line-amp and EQ
sections in Neve consoles such as the 8048. A look through the credits on today’s top selling CDs
will reveal that these vintage consoles are still widely used to great effect and that the 1081 module
has become a hugely popular design classic.This is why AMS Neve have resumed production of the
1081, using the original components and construction methods.

Installation

The 1081 is available as a stand-alone module, or in a choice of two housings that provide power
supply, phantom power switching for each module and connectors for balanced inputs (mic and
line) and outputs:

dB

80

70

20

60

50

40

MIC

30

10

20

dB

80

70

20

60

50

40

MIC

30

10

20

3

·3

3

·3

KHz

4

·7

2

10

68

·

0

10

+10

15

LINE

10

68

·

0

10

+10

15

LINE

·7

2

·2

1

·8

1·5

OFF

OFF

3

·3

3

·3

KHz

4

·7

2

·7

2

·2

1

·8

1·5

OFF

OFF

470

3·9

390

Hi

330

4

·7

Q

270

5

·6

Hi

220

6

·8

Q

OFF

8

·2

470

3·9

390

Hi

330

4

·7

Q

270

5

·6

Hi

220

6

·8

Q

OFF

8

·2

303

Hz

0

81

560

680

820

1000

1200

Hz

560

680

820

1000

1200

270

39

0

10

56

33

OFF

303

0

81

0

10

56

33

OFF

·

56

·

150

82

47

27

Hz

270

150

82

47

27

Hz

SOLO

8·2

EQ

PH

12

18

OFF

KHz

39

·

56

·

SOLO

8·2

EQ

PH

12

18

OFF

KHz

PHANTOM

+48V

CH1

CH2

+24V

OUTPUT

AMS

NEVE

1

2

MAINS

The 3U rack houses two modules mounted horizontally ina 19” rack-mounting unit. Therear panel
has XLRs for transformer balanced I/O and a 25-way ‘D’-type connector for solo and spare switch
contacts and unbalanced outputs plus an IEC connector for mains power.

dB dB dB dB dB dB dB dB

80 80 80 80 80 80 80 80

20 20 20 20 20 20 20 20

70 70 70 70 70 70 70 70

60 60 60 60 60 60 60 60

10 10 10 10 10 10 10 10

00000000

50 50 50 50 50 50 50 50

+10+10+10+10+10+10+10+10

40 40 40 40 40 40 40 40

LINE LINE LINE LINE LINE LINE LINE LINE

MIC MIC MIC MIC MIC MIC MIC MIC

30 30 30 30 30 30 30 30

10 10 10 10 10 10 10 10

20 20 20 20 20 20 20 20

OFF OFF OFF OFF OFF OFF OFF OFF

15 15 15 15 15 15 15 15

10 10 10 10 10 10 10 10

68

·

KHz KHz KHz KHz KHz KHz KHz KHz

4

·7

3

·3

OFF OFF OFF OFF OFF OFF OFF OFF

8

·2

6

·8

1·51·51·51·51·51·51·51·5

5

·6

1

·8

2

·2

4

·7
KHzKHzKHzKHzKHzKHzKHzKHz

3·9 3·9 3·9 3·9 3·9 3·9 3·9 3·9

2

·7

3

·3

HiQHiQHiQHiQHiQHiQHiQHiQ

HiQ HiQ HiQ HiQ HiQ HiQ HiQ HiQ

1111111122222222

0000000000000000

OFF OFF OFF OFF OFF OFF OFF OFF

11111111000000000000000000000000

2222222200000000

88888888

66666666

Hz Hz Hz Hz Hz Hz Hz Hz

Hz Hz Hz Hz Hz Hz Hz HzHz Hz Hz Hz Hz Hz Hz Hz

82 82 82 82 82 82 82 82

Hz Hz Hz Hz Hz Hz Hz Hz

000000002222222222222222

777777770000000022222222

8888888800000000

333333333333333300000000

55555555

6666666600000000

33333333

9999999900000000

44444444

7777777700000000

OFF OFF OFF OFF OFF OFF OFF OFF

33 33 33 33 33 33 33 33

56 56 56 56 56 56 56 56

111111110000000000000000

00000000

8888888811111111

333333330000000033333333

39

·

270 270 270 270 270 270 270 270

56

·

150 150 150 150 150 150 150 150

8·28·28·28·28·28·28·28·2

12 12 12 12 12 12 12 12

47 47 47 47 47 47 47 47

KHz KHz KHz KHz KHz KHz KHz KHz

18 18 18 18 18 18 18 18

27 27 27 27 27 27 27 27

OFF OFF OFF OFF OFF OFF OFF OFF

PH PH PH PH PH PH PH PH

EQ EQ EQ EQ EQ EQ EQ EQ

SOLO SOLO SOLO SOLO SOLO SOLO SOLO SOLO

68

·

4

·7

3

·3

8

·2

6

·8

5

·6

1

·8

2

·2

4

·7

2

·7

3

·3

39

·

56

·

68

·

4

·7

3

·3

8

·2

6

·8

5

·6

1

·8

2

·2

4

·7

2

·7

3

·3

39

·

56

·

68

·

4

·7

3

·3

8

·2

6

·8

5

·6

1

·8

2

·2

4

·7

2

·7

3

·3

39

·

56

·

68

·

4

·7

3

·3

8

·2

6

·8

5

·6

1

·8

2

·2

4

·7

2

·7

3

·3

39

·

56

·

68

·

4

·7

3

·3

8

·2

6

·8

5

·6

1

·8

2

·2

4

·7

2

·7

3

·3

39

·

56

·

68

·

4

·7

3

·3

8

·2

6

·8

5

·6

4

·7

3

·3

3

·3

8

·2

6

·8

5

·6

1

·8

2

·2

4

·7

2

·7

3

·3

39

·

56

·

68

·

4

·7

1

·8

2

·2

2

·7

39

·

56

·

+48V

+24V

AMS

NEVE

PHANTOM OUTPUT

CH1

CH2

CH3

CH4

CH5

CH6

CH7

CH8

MAINS

1

2

3

4

5

6

7

8

The 7U rack houses 8 modules vertically in a 19” rack-mounting unit. The rear panel has XLRs for
transformer balanced I/O and a 25-way ‘D’-type connector for solo and spare switch contacts and
unbalanced outputs plus an IEC connector for mains power.

User Guide Issue 3 Page 1

1081 Channel Amplifier Dimensions

Dimensions

Stand-alone Module

Dimensions: Front panel 45mm x 305 mm (1.8 inches x 12 inches).

Approx 300mm (12 inches) deep behind the front panel.

Approx. Weight: 3kg (6.6 lbs)

Rack Data

19" Rack Mounting U Depth

mm (inches)

2 Module Version 3 400 134 (5¼) 17 (37) *

8 Module Version 7 400 311 (12¼) 46 (101) *

Height

mm (inches)

Approx. Weight

kg (lbs)

* Fully populated rack

The 7U unit is heavy (over 20kg) and should be handled by two persons.

User Guide Issue 3 Page 2

1081 Channel Amplifier Power Requirements

Power Requirements

3U 7U

Rated Voltage 100-230V AC 100-230V AC

Rated Frequency 50-60 Hz 50-60Hz

Rated Current 0.5A Max 0.8A Max

Surge Current (In Rush) Cold
Surge Current (In Rush) Hot

Earth Leakage Current Approx 1.2mA Approx 1.3mA

Warning for High Earth Leakage
Current Required

Primary Protection Fuse:

Operating Voltage 100-230V AC 100-230V AC

Fuse Rating and Type T1.6A H 250V

Location IEC Mains connector IEC Mains connector

Secondary Protection Fuse:

Output Voltage 24V DC 24V DC

Fuse Rating and Type T 1.0A L 250V

Location F1 on SZN825-058 F1 on SZN825A058

Output Voltage 48V DC 48V DC

Fuse Rating and Type T 500mA L 250V

Location F2 on SZN825-058 F2 on SZN825A058

31.0A

33.0A

NO NO

20mm x 5mm CERAMIC

20mm x 5mm GLASS

20mm x 5mm GLASS

31.0A

33.0A

T1.6A H 250V
20mm x 5mm CERAMIC

T 2.0A L 250V
20mm x 5mm GLASS

T 500mA L 250V

20mm x 5mm GLASS

Stand-alone 1081 Module

Power 192mA at 24V DC. Negative Earth

Mains Supply (rack units)

The power supply unit is a universal input type therefore no mains operating voltage setting is
required.

The mains switch on the front panel of the 3U and 7U rack units is non-illuminating.

The CH (chassis) and 0V Link should be connected or instability may result.

User Guide Issue 3 Page 3

1081 Channel Amplifier Phantom Power

Mains Fuse (rack units)

The mains fuse is located in the IEC mainsinput connector on the rear ofthe 3U and 7U rack units.

Secondary Protection Fuses (rack units)

Secondary protection fuses for the 24V and 48V supplies are located behind the front panel on the
power supply filter PCB SZN825-058 in both 3U and 7U rack units.

DC Power Supply Indicators (rack units)

The red LED on the front panel of both 3U and 7U rack units indicates +24V power healthy when
illuminated.
The green LED on the front panel of both 3U and 7U rack units indicates +48V power healthy when
illuminated.

Phantom Power

Phantom power can be supplied toeach module by pressing the phantom power switch on the front
panel of the 3U or 7U rack. The LED in the switch will illuminate confirming that phantom power is
supplied.

Output Level Control

Each channel has an independent Output Level Control. The control is post-input, post-EQ and
pre-output. This control allows the input and EQ to operate at a higher level and then for the signal
to be returned to a normal operating level at the output.

When the Output Control is fully clockwise the output gain is unity. The output is 10dB down with
the control in the mid-position.

User Guide Issue 3 Page 4

1081 Channel Amplifier Amplifier Controls

Amplifier Controls

dB

80

20

70

60

50

40

MIC

6·8

5·6

4·7

1000

20

8

680

Hz

HzHz

82

47

Hz

10

0

+10

LINE

30

10

20

OFF

15

10

·

68

KHz

4·7

3·3

OFF

8·2

1·5

1·8

2·2

KHz

3·9

2·7

3·3

HiQ

HiQ

12

00

OFF

022

702

330

5

60

390

470

OFF

33

56

100

0

81

303

39·

270

56·150

8·2

12

KHz

18

27

OFF

PH

EQ

SOLO

H.F. Controls: 5 switched frequencies, shelving or peaking curve, continuously

variable 18dB cut or boost.

H.F. Presence: 10 switched frequencies with continuously variable 18dB cut or

boost, high or low Q selection.

L.F. Presence: 10 switched frequencies with continuously variable 18dB cut or

boost, high or low Q selection.

L.F. Controls: 5 switched frequencies, shelving or peaking curve, continuously

variable 18dB cut or boost.

H.P. Filter: 5 switched frequencies with slope of 18dB per octave.

L.P. Filter: 5 switched frequencies with slope of 18dB per octave.

PH Button: Gives 180° phase change at the balanced output.

EQ Button: Selects equalisation in or out of circuit.

SOLO Button: Selects channel unbalanced output and closing switch contact.

Spare Button: Switches external device as required.

dB

80

70

20

60

50

40

MIC

10

0

+10

LINE

30

10

20

3

·3

4

·7

·

68

10

15

OFF

3

·3

KHz

3·9

2

·7

2

·2

1

·8

1·5

4

6

OFF

8

·2

470

560

390

Hi

330

·7

Q

270

5

·6

Hi

220

·8

Q

820

1000

OFF

1200

303

Hz

0

81

0

680

10

56

33

OFF

39

·

270

56

150

82

47

Hz

·

SOLO

8·2

EQ

PH

12

18

27

OFF

KHz

User Guide Issue 3 Page 5

1081 Channel Amplifier EMI Filter Components

EMI Filter Components

Jumpers may be fitted on the SUN870-081 I/O boards to allow the EMI filtering (three terminal
capacitors and common mode inductors) to be ‘removed’ from the signal path. This may be
desirable for those seeking sonic purity. However it must be noted that the immunity of the product
to external RF fields could suffer, and if thisis the case then the jumperlinks should be removed.

The individual 1081 modules are offered for inclusion in the customers own housings. As such no
claim is being made regarding the immunity of these units. This will be principally governed by the
type of cabling, connectors and enclosure used. The use of screened cables and connectors is
recommended for all connections. Tests have shown that no problems with emissions as defined in
EMC standards should be present with these units.

User Guide Issue 3 Page 6

1081 Channel Amplifier Rear Panel Views

Rear Panel Views

ACM AINSI/P

MIC 1 LINE 1 O/P 1

CH 0V

MIC 8 MIC 7 MIC 6 MIC 5 MIC 4 MIC 3 MIC 2 MIC 1

LINE 8

O/P 8

MIC 2 LINE 2 O/P 2

LINE 6LINE 7 LINE 5

O/P 6O/P 7 O/P 5

AUXILARY

LINE 3LINE 4 LINE 2

O/P 3O/P 4 O/P 2

LINE 1

O/P 1

AC MAINS I/P

CH 0V

AUXILARY 7-8 AUXILARY 5-6 AUXILARY 3-4 AUXILARY1- 2

User Guide Issue 3 Page 7

1081 Channel Amplifier Connector Details

Connector Details

1081 Stand-alone

Wiring to 18 way Free Plug

Spare

Solo

A

B

C

Spare Switch Contact

D

E

F

H

J

K

L

M

Solo Switch Contact

N

P

R

S

T

U

0V

Link

Hi

Mic I/P

Lo

0V

Hi

Line I/P

Lo

Unbalanced O/P

Hi

BAL O/P

Lo

0V

Solo O/P (unbalanced)

+24V at 192mA

0dBu

0dBu

Technical

Earth Link

-10dBu

0dBu

-10dBu

V

User Guide Issue 3 Page 8

1081 Channel Amplifier Connector Details Continued

2

2

2

2

7
8

Connector Details Continued

Rear of 1081 2 Module (3U) and 8 Module (7U) Racks

25 way D Auxiliary and XLR Wiring

25 way D-Type

Wiring View

1

NC

14

NC

Chassis Earth

Unbalanced 0V

Solo 1

Spare 1

Chassis Earth

Spare 2

Solo 2

Unbalanced 0V

Chassis Earth

2

15

3

16

4

17

5

18

6

19

7

20

8

21

9

22

10

23

11

24

12

25

NC

13

NC

Unbalanced O/P

Chassis Earth

Solo O/P (unbalanced)

Solo Switch Contacts CH1

Spare Switch Contacts CH1

Spare Switch Contacts

Solo Switch Contacts

Solo O/P (unbalanced)

Chassis Earth

Unbalanced O/P

-10dBu

-10dBu

-10dBu

-10dBu

For the 8 Module Rack :

CH 1

CH 1

CH

CH

CH

CH

CH1 is CH1, CH 3, CH 5 or CH
CH2isCH2,CH4,CH6orCH

XLR

Wiring View

Mic/Line I/P (Balanced)

Hi

Lo

Plug

12

3

O/P (Balanced)

Socket

12

3

Hi

Lo

User Guide Issue 3 Page 9

1081 Channel Amplifier Specifications

Specifications

Microphone Input: Zin 300 or 1200 ohms switched,

gain +80 to +10 dB in 5dB steps.

Line Input: Zin 10k ohms bridging, gain +20 to -15dB in 5dB steps.

Both inputs are balanced and earth-free.

Outputs: Max +26dB into 600 ohms. Zout 75 ohms ±5% @ 1kHz,

balanced and earth-free. An unbalanced output 8dB below
the level of the balanced output is also provided.

Distortion: Not more than 0.07% for +20dBm output from 50Hz to 15kHz.

Frequency Response: ±0.5dB from 20Hz to 20kHz. -3dB at 7Hz and 35kHz.

Noise: Output noise better than -42dBm from Zin 1200 ohms and

-80dB input, giving an equivalent noise of -125dBm referred to
600 ohms input impedance fed from 100 ohms. Output noise
better than - 80dBm at all line input levels.

User Guide Issue 3 Page 10

1081 Channel Amplifier Service Information

Service Information

Schematic Drawing index

PL31081- Channel Amplifier Horizontal and Vertical module versions:

PL31081-C Channel Amplifier

PL10306-C Dual Voltage Follower

PL10312-C Channel Amplifier Motherboard

PL10338-C High Gain Amplifier

PL10340-C Output Amplifier

PL20046 Sensitivity Switch

PL20047 Treble Switch Assembly

PL20048/4 Upper Presence Switch Assembly

PL20048/5 Lower Presence Switch Assembly

PL20049 LP/HP Filter Switch Assembly

PL20050 Bass Switch Assembly

AM3631 - 3U Rack:

AM3631 2 CH 1081 Mainframe Assembly Detail

SZN825-058 PSU Filter PCB

SSN818-036 0V Stud Filter PCB

SUN870-081 2CH I/P O/P Backplane

SYN824-128 2 Switch Phantom Power PCB

NN3726 Chassis Cable Assy

AM3630 - 7U Rack:

AM3630 8 CH 1081 Mainframe Assembly Detail

SZN825A058 PSU Filter PCB

Same as the 3U Rack

User Guide Issue 3 Page 11

1081 Channel Amplifier 1081 Recall Sheet - Horizontal Module

1081 Recall Sheet - Horizontal Module

User Guide Issue 3 Page 12

1081 Channel Amplifier 1081 Recall Sheet - Vertical Module

1081 Recall Sheet - Vertical Module

User Guide Issue 3 Page 13