Glensound U2B2, U2B4, U2B8 User Manual

U2B2, 4 & 8

UNBALANCED TO BALANCED

CONVERTERS

2, 4 & 8 Mono (1, 2 & 4 Stereo) balancing audio & gain

converters

User Guide

Glensound

6 Brooks Place, Maidstone

Kent, UK, ME14 1HE

Tel: [phone]

www.glensound.co.uk

Page 2 of 20

Glensound Electronics Ltd

Thank you for choosing a new Glensound product.

All rights reserved.

Information contained in this manual is subject to change without notice, if in

doubt please contact us for the latest product information.

If you need any help with the product then we can be contacted at:

Glensound Electronics Ltd

1 – 6 Brooks Place

Maidstone

Kent

ME14 1HE

United Kingdom

Telephone: [phone]

Fax: [phone]

EMAIL ADDRESSES

General enquires: [email protected]

Technical enquires: [email protected]

Sales enquires: [email protected]

Page 3 of 20

IMPORTANT SAFETY INSTRUCTIONS

1) Read these instructions

2) Keep these instructions

3) Heed all warnings

4) Follow all instructions

5) Do not use this apparatus near water

6) Clean only with a dry cloth

7) Do not block any ventilation openings. Install in accordance with manufacturer’s

instructions

8) Do not install near any heat sources such as radiators, heat registers, stoves, or other

apparatus (including amplifiers) that produce heat

9) Do not defeat the safety purpose of the polarized or grounding type plug. A polarized plug

has 2 blades with one wider than the other. A grounding type plug has 2 blades and third
grounding prong. The wider blade or the 3rd prong are provided for your safety. If the
provided plug does not fit into your outlet, consult an electrician for replacement of the
obsolete outlet

10) Protect the power cord from being walked on or pinched, particularly at plugs,

convenience receptacles and the point where they exit from the apparatus

11) Only use attachments/ accessories specified/ supplied by the manufacturer

12) Use only with the cart, stand, tripod, bracket, or table specified by the

manufacturer, or sold with the apparatus. When a cart is used, use caution when moving
the cart/ apparatus combination to avoid injury from tip over

13) Unplug tis apparatus during lightning storms or when unused for long periods of time

14) Refer all servicing to qualified service personnel. Servicing is required when the apparatus

has been damaged in any way, such as power supply cord or plug is damaged, liquid has
been spilled or objects have fallen into the apparatus, the apparatus has been exposed to
rain or moisture, does not operate normally, or has been dropped

15) Do not attempt to modify this product. Doing so could result in personal injury and/ or

product failure

This symbol is intended to warn that
dangerous voltages within the product are
present and constitute a risk of electric

shock.

This symbol is intended to highlight that
there are important operating &
maintenance instructions in the literature
accompanying this unit.

Page 4 of 20

IMPORTANT: MAINS PLUG WIRING INSTRUCTIONS

This Signature unit is supplied with a moulded mains plug fitted to the AC mains
lead.

Mains wiring colours/ connections:

The Green/ Yellow or Green wire must be connected to the terminal in the plug
marked ‘E’ or with the Earth Symbol.

The Blue or Black wire must be connected to the terminal in the plug marked ‘N’
(Neutral).

The Red or Brown wire must be connected to the terminal in the plug marked ‘L’
(Live).

THIS UNIT MUST BE EARTHED

THIS UNIT IS FITTED WITH AN INTERNAL MAINS FUSE.

The fuse is located internally between the Live terminal of the IEC plug and the
Live input of the power supply. The fuse should only be changed by a qualified
service engineer. If replacing the fuse care should be taken to fit a correctly rated
replacement. The fuse rating can be found in the technical specifications page of
this handbook.

Page 5 of 20

CE

This equipment manufactured by Glensound Electronics Ltd of Brooks Place

Maidstone Kent ME14 1HE is CE marked and conforms to:

Low Voltage Directive: EN60065

Emissions: EN55103.1

Immunity: EN55103.2

WASTE ELECTRICAL AND ELECTRONIC EQUIPMENT

REGULATIONS 2006 (WEEE)

Glensound Electronics Ltd is registered for business to business sales of WEEE in
the UK our registration number is:

WEE/JJ0074UR

RoHS2 DIRECTIVE

EC directive 2011/65/EU restricts the use of the hazardous substances listed below
in electrical and electronic equipment.

This product conforms to the above directive and for this purposes, the maximum
concentration values of the restricted substances by weight in homogenous
materials are:

Lead

0.1%

Mercury

0.1%

Hexavalent Chromium

0.1%

Polybrominated Biphenyls

0.1%

Polybrominated D

iphenyl Ethers

0.1%

Cadmium

0.01%

Page 6 of 20

PRODUCT WARRANTY:

All equipment is fully tested before dispatch and carefully designed to provide you

with trouble free use for many years.

We have a policy of supporting products for as long as possible and guarantee to

be able to support your product for a minimum of 10 years.

For a period of one year after the goods have been despatched the Company will

guarantee the goods against any defect developing after proper use providing

such defects arise solely from faulty materials or workmanship and that the

Customer shall return the goods to the Company’s works or their local dealer.

All non-wear parts are guaranteed for 2 years after despatch and any defect

developing after proper use from faulty materials or workmanship will be repaired

under this warranty providing the Customer returns the goods to the Company's

works or their local dealer.

Page 7 of 20

U2B2, 4 & 8 Unbalanced to Balanced Converters

Handbook Contents

Issue 1,

Description Page No.

Contents

IMPORTANT SAFETY INSTRUCTIONS ........................................................................................................................ 3

PRODUCT WARRANTY: ...................................................................................................................................................... 6

OVERVIEW .......................................................................................................................................................................... 8

PHYSICAL INSTALLATION ................................................................................................................................................. 9

AUDIO BLOCK DIAGRAMS .............................................................................................................................................. 11

EXAMPLES OF USE ........................................................................................................................................................... 13

1. Domestic Products Interface to a Broadcast Desk ........................................................................................... 13

USER CONTROLS & CONNECTIONS ................................................................................................................................ 14

1. Power On LED ..................................................................................................................................................... 14

2. Unbalanced Stereo Input 1 ................................................................................................................................ 15

3. Balanced Stereo Output 1.................................................................................................................................. 15

4. Unbalanced Stereo Input 2 ................................................................................................................................ 15

5. Balanced Stereo Output 2.................................................................................................................................. 15

6. Input 1 Gain Controls ......................................................................................................................................... 16

7. Input 2 Gain Controls ......................................................................................................................................... 16

8. External DC Input ............................................................................................................................................... 16

9. Mains In ............................................................................................................................................................... 16

WIRING INFORMATION ................................................................................................................................................... 17

1. Standard Pin Outs............................................................................................................................................... 17

TECHNICAL SPECIFICATION U2B2 .................................................................................................................................. 18

TECHNICAL SPECIFICATION U2B4 .................................................................................................................................. 19

TECHNICAL SPECIFICATION U2B8 .................................................................................................................................. 20

Page 8 of 20

OVERVIEW

This handbook covers three products all with the same facilities just with different quantities
of these facilities.

Signature U2B2 is a single stereo/ dual mono unbalanced to balanced converter.

Signature U2B4 is a twin stereo/ quad mono unbalanced to balanced converter.

Signature U2B8 is a quad stereo/ octa mono unbalanced to balanced converter.

The Glensound Signature Series U2B range are professional audio balance converters. They
are manufactured using high quality components and low noise audio circuits to provide
many years of trouble free use.

The primary job of the U2B range is to interface domestic type audio outputs (unbalanced) to
the balanced audio inputs on broadcast and professional audio equipment.

As well as providing a balanced interface the U2B range also provides variable gain/ loss to
allow the lower level audio outputs produced by domestic equipment to be raised to meet
the higher level broadcast and pro audio standard.

The stereo audio inputs (which can all work as dual monos) are on gold plated RCA phono
connectors. These inputs are electronically isolated with RF filters to prevent extraneous
signals, and fed via multi-turn preset gain controls on the rear panel to pairs of electronically
balanced and isolated outputs on Neutrik XLRs.

The rear panel gain controls are multi-turn presets to allow accurate gain setting and are also
recessed to prevent accidental movement.

Although traditionally a broadcast manufacturer, Glensound’s products are equally at home
in professional and high end home studios, industrial installations and live pro sound
environments. The U2B range can therefore be used in a number of applications.

The U2B range are powered from internal switch mode mains power supplies fed from
filtered IEC mains plugs suitable for use Worldwide. They have an internal fuse for safety. The
units can also alternatively be powered from external +/-12V DC power sources (such as the
Signature Series PS1). If both mains and external DC power sources are present then, if one
power source were to fail the unit would continue to work seemlessly from the other source.

Page 9 of 20

PHYSICAL INSTALLATION

The Glensound Signature Series have been designed to be highly versatile for installation and
can be installed in 19” racks with either their front or rear panels facing the front of the rack.
They can also be mounted underneath desks or work tops and can be either permananetly
mounted or stood (using the supplied feet) on top of desks or worktops.

INSTALLING SIGNATURE SERIES IN A 19” RACK

Firmly hold the signature subrack within the 19” rack and locate in 1RU of space. Use the
supplied 6mm rack screws to securly attach the unit to the rack.

INSTALLING ADHSIVE FEET FOR NON PERMANENT TABLE TOP MOUNTING

Remove the front rack ears (if they are not required), turn the unit upside down and attach
the supplied 4 sticky feet as per the above drawing.

Signature

g

Series

Keeps Working

PWR ON

PART No

CE

W

50/60Hz 2.7 Watts

100-240V

+/-12V

- - -

PIN 1 = GND

PIN 3 = -12V (100mA)
PIN 2 = +12V (100mA)

Top

Page 10 of 20

SWAPPING RACK EARS TO ALLOW THE REAR TO BE INSTALLED AT THE FRONT OF A

RACK

First remove the 4 silver button head screws that fix the rack ears onto the front of the unit as
shown in the top picture above.

Remove the rack ears and turn the unit around for access to its back panel.

Re-fit the 2 rack ears using the same 4 silver button head screws that were removed from the
front as per the bottom picture above.

USING THE MOUNTING HOLES FOR PERMANENTLY ATTACHING THE UNIT ABOVE OR

BELOW A WORKTOP/ DESK

Use either the top or bottom mounting holes as indicated above to use suitable screws to
attach the signature unit to a worktop or bench. **PLEASE ENSURE THAT YOU USE SUITABLE
FIXINGS**

Series

Signature

g

Keeps Working

PWR ON

PART No

CE

W

50/60Hz 2.7 Watts

100-240V

+/-12V

- - -

PIN 1 = GND

PIN 3 = -12V (100mA)

PIN 2 = +12V (100mA)

Series

Signature

g

Keeps Working

PART No

PWR ON

Page 11 of 20

AUDIO BLOCK DIAGRAMS

1. U2B2

2. U2B4

UNBALANCED INPUTS

100 - 240 VAC

INTERNAL

FUSE

AC/DC PSU

+12V

-12V

EXT DC +/-12V

PRESET GAIN

BALANCED OUTPUTS

UNBALANCED INPUTS

100 - 240 VAC

INTERNAL

FUSE

AC/DC PSU

+12V

-12V

EXT DC +/-12V

PRESET GAIN

BALANCED OUTPUTS

UNBALANCED INPUTS

PRESET GAIN

BALANCED OUTPUTS

Page 12 of 20

3. U2B8

UNBALANCED INPUTS

100 - 240 VAC

INTERNAL

FUSE

AC/DC PSU

+12V

-12V

EXT DC +/-12V

PRESET GAIN

BALANCED OUTPUTS

UNBALANCED INPUTS

PRESET GAIN

BALANCED OUTPUTS

UNBALANCED INPUTS

PRESET GAIN

BALANCED OUTPUTS

UNBALANCED INPUTS

PRESET GAIN

BALANCED OUTPUTS

Page 13 of 20

EXAMPLES OF USE

1. Domestic Products Interface to a Broadcast Desk

ON AIR MIXING DESK

4 x Short Pairs of
RCA Phono Cables

2 x XLR32 x XLR32 x XLR3

2 x XLR3

4 x Pairs o f
XL R C ables

Many radio stations and studios incorporate mid level domestic audio equipment such as CD
players & recorders, FM/ DAB Tuners, PCs tape machines etc as they provide reasonable value
for money in comparison to professional versions. The output of such devices need to be
correctly interfaced with a professional or broadcast audio desk.

In this example the U2B8 will be located near the domestic devices (often a long way from
studio in a racks room) as it is prudent to keep the unbalanced audio cables as short as
practicable.

The U2B8 is performing both balance conversion and allowing long balanced cable distances
to be achieved to the studio.

It is also adding gain to lift the low domestic output levels of the equipment to a suitable level
for the professional mixing desk.

Page 14 of 20

USER CONTROLS & CONNECTIONS

Note: Picture & description is for the U2B4 but facilities scale up to the U2B8 and
down to the U2B2.

FRONT PANEL

1. Power On LED

The front panel bright blue LED shows that the unit is powered on and functioning correctly.

1. POWER ON LED

Page 15 of 20

REAR PANEL

2. Unbalanced Stereo Input 1

One pair of stereo (can be used dual mono) RCA phono unbalanced audio inputs. The white
connector is normally used for the left audio channel of a stereo pair and the red connector is
usually used for the right audio channel of a stereo pair.

3. Balanced Stereo Output 1

These Neutrik 3 pin XLR plugs provided the balanced audio outputs of the input 1 audio
source. They are electronically balanced with wide band low noise circuitry. The output level
can be adjusted using gain controls (see 6).

4. Unbalanced Stereo Input 2

One pair of stereo (can be used dual mono) RCA phono unbalanced audio inputs. The white
connector is normally used for the left audio channel of a stereo pair and the red connector is
usually used for the right audio channel of a stereo pair.

5. Balanced Stereo Output 2

These Neutrik 3 pin XLR plugs provided the balanced audio outputs of the input 2 audio
source. They are electronically balanced with wide band low noise circuitry. The output level
can be adjusted using gain controls (see 7).

4. UNBALANCED
STEREO INPUT 2

5. BALANCED STEREO
OUTPUT 2

8. EXTERNAL DC IN

9. AC MAINS INPUT

2. UNBALANCED
STEREO INPUT 1

3. BALANCED STEREO
OUTPUT 1

6. INPUT 1 GAIN/
LOSS

7. INPUT 2 GAIN/
LOSS

Page 16 of 20

6. Input 1 Gain Controls

These multi turn preset potentiometers adjust the audio level between the unbalanced
inputs and the balanced outputs. Turning the potentiometer clockwise increases the gain
(and therefore the output level) and turning the potentiometer anti-clockwise decreases the
gain (and therefore reduces the output level).

7. Input 2 Gain Controls

These multi turn preset potentiometers adjust the audio level between the unbalanced
inputs and the balanced outputs. Turning the potentiometer clockwise increases the gain
(and therefore the output level) and turning the potentiometer anti-clockwise decreases the
gain (and therefore reduces the output level).

8. External DC Input

This DC input can be used instead or as well as the mains input. It requires a +/- 12V power
source (such as our PS1). If used in conjunction with the mains input it will seamlessly provide
a redundant power source.

9. Mains In

This AC input accepts a wide range power supply, suitable for use Worldwide. If used in
conjunction with the external DC supply then a seamless redundant power supply will be

provided.

Page 17 of 20

WIRING INFORMATION

1. Standard Pin Outs

RCA PHONO PLUG (MALE)

12

3

XLR SOCKET (FEMALE)

1 2

3

XLR PLUG (MALE)

CONTACT

SLEEVE

STANDARD XLR AUDIO PINOUTS:

1: Ground/ Earth

2: INPHASE/ POSITIVE/ MIC +

3: MATE/ NEGATIVE/ MIC -

UNBALANCED RCA PHONO

CONTACT: Signal

SLEEVE: Common/ Earth

Page 18 of 20

TECHNICAL SPECIFICATION U2B2

AUDIO

Frequency Response @ Line Up

Input Impedance

Crosstalk

Maximum Input Level

Distortion

Input Type

Gain Range

Output Impedance

Output Type

Maximum Output Level

Noise

<=/-0.1dB 40Hz to 20kHz

>22k Ohm

<-90dBu 1kHz to 15kHz @ lineup

>+28dBu

0.04% THD @ 100Hz, 1kHz & 0.01% @ 10kHz
Reference to +0dBu output

Electronically balanced on Gold Plated
RCA Phono socket

-15dB to +15dB on each output

=<50 Ohms

Electronically balanced on Neutrik
3 pin XLR plug

+24dBu

-98dB @ line up unweighted
RMS (22Hz to 22kHz) ref +8dBu output

Line Up Level (with 0dB Gain)

-12dBu on unbalanced input = 0dBu on
balanced output

FEATURES

POWER

PHYSICAL

Mains Input

Size

Internal Mains Fuse

Shipping Weight

DC Input

Mechanics

AC Consumption

Weight

Shipping Carton

Filtered IEC, 100 to 240VAC
47 - 63Hz

338 x 123 x 44mm (LxDxH) no rack ears
482mm 19” (1RU) with rack ears

20mm 1A Anti Surge

2.3kg

4 Pin Neutrik XLR plug +/- 12V

All aluminium construction, anodized and
laser etched

1.3 Watts @ 230VAC

1.00kg

Rugged export quality cardboard carton
610 x 420 x 130mm LxDxH

INCLUDED

Mains Lead

Quick Start Guide

Feet

Rack Bolts

Handbook

2 Metre Long Mains Lead
(UK & Europe only)

Printed A4 two sided quick start guide

4 off rubber stick on feet

4 off Hex head M6

Full A4 handbook available to download
and linked by QR code on device

Page 19 of 20

TECHNICAL SPECIFICATION U2B4

FEATURES

POWER

AUDIO

PHYSICAL

Mains Input

Size

Internal Mains Fuse

Shipping Weight

DC Input

Mechanics

AC Consumption

Weight

Shipping Carton

Filtered IEC, 100 to 240VAC
47 - 63Hz

338 x 123 x 44mm (LxDxH) no rack ears
482mm 19” (1RU) with rack ears

20mm 1A Anti Surge

2.3kg

4 Pin Neutrik XLR plug +/- 12V

All aluminium construction, anodized and
laser etched

1.7 Watts @ 230VAC

1.00kg

Rugged export quality cardboard carton
610 x 420 x 130mm LxDxH

Frequency Response @ Line Up

Input Impedance

Crosstalk

Maximum Input Level

Distortion

Input Type

Gain Range

Output Impedance

Output Type

Maximum Output Level

Noise

<=+/-0.1dB 40Hz to 20kHz

>22k Ohm

<-90dBu 1kHz to 15kHz @ lineup

>+28dBu

0.04% THD @ 100Hz, 1kHz & 0.01% @ 10kHz
Reference to +0dBu output

Electronically balanced on Gold Plated
RCA Phono socket

-15dB to +15dB on each output

=<50 Ohms

Electronically balanced on Neutrik
3 pin XLR plug

+24dBu

-98dB @ line up unweighted
RMS (22Hz to 22kHz) ref +8dBu output

Line Up Level (with 0dB Gain)

-12dBu on unbalanced input = 0dBu on
balanced output

INCLUDED

Mains Lead

Quick Start Guide

Feet

Rack Bolts

Handbook

2 Metre Long Mains Lead
(UK & Europe only)

Printed A4 two sided quick start guide

4 off rubber stick on feet

4 off Hex head M6

Full A4 handbook available to download
and linked by QR code on device

Page 20 of 20

TECHNICAL SPECIFICATION U2B8

FEATURES

POWER

AUDIO

PHYSICAL

Mains Input

Size

Internal Mains Fuse

Shipping Weight

DC Input

Mechanics

AC Consumption

Weight

Shipping Carton

Filtered IEC, 100 to 240VAC
47 - 63Hz

445 x 123 x 44mm (LxDxH) no rack ears
482mm 19” (1RU) with rack ears

20mm 1A Anti Surge

2.4kg

4 Pin Neutrik XLR plug +/- 12V

All aluminium construction, anodized and
laser etched

2.6 Watts @ 230VAC

1.10kg

Rugged export quality cardboard carton
610 x 420 x 130mm LxDxH

Frequency Response @ Line Up

Input Impedance

Crosstalk

Maximum Input Level

Distortion

Input Type

Gain Range

Output Impedance

Output Type

Maximum Output Level

Noise

<=+/-0.1dB 40Hz to 20kHz

>22k Ohm

<-90dBu 1kHz to 15kHz @ lineup

>+28dBu

0.04% THD @ 100Hz, 1kHz & 0.01% @ 10kHz
Reference to +0dBu output

Electronically balanced on Gold Plated
RCA Phono socket

-15dB to +15dB on each output

=<50 Ohms

Electronically balanced on Neutrik
3 pin XLR plug

+24dBu

-98dB @ line up unweighted
RMS (22Hz to 22kHz) ref +8dBu output

Line Up Level (with 0dB Gain)

-12dBu on unbalanced input = 0dBu on
balanced output

INCLUDED

Mains Lead

Quick Start Guide

Feet

Rack Bolts

Handbook

2 Metre Long Mains Lead
(UK & Europe only)

Printed A4 two sided quick start guide

4 off rubber stick on feet

4 off Hex head M6

Full A4 handbook available to download
and linked by QR code on device