Hoellstern DELTA 6.2-DSP, DELTA 7.2, DELTA 7.2-DSP, DELTA 12.2, DELTA 12.2-DSP User Manual

AUDIO AMPLIFIERS

MANUAL

AUDIO AMPLIFIERS

Hoellstern® audio amplifiers are „engineered and made in
Germany”. This means for you:
designed and manufactured in premium quality. The no-compromise
component selection and a circuit design according to space
technology criteria provide ultimate reliability.

Since January 2004 Hoellstern

®

audio amplifiers have proven their

high reliability under the toughest conditions – live.

Hoellstern® amplifies.
Unusually good – strikingly audiophile – with superior cost-effectiveness.

Amplifier (Option) In x Out

Output Power

8 Ohm 6 Ohm 4 Ohm 2,7 Ohm 2 Ohm 1,6 Ohm 1 Ohm Bridged

DELTA6.2-DSP 2x2 850 W 1,275 W 1,700 W 2,550 W 3,400 W – – 6,800 W

DELTA7.2(-DSP) 2x2 1,000 W 1,325 W 2,000 W 3,000 W 4,000 W 5,000 W – 10,000 W

DELTA12.2(-DSP) 2x2 2,200 W 2,900 W 4,400 W 6,300 W 8,000 W – – 16,000 W

DELTA12.4(-DSP) 4x4 600 W 800 W 1 150 W 1,700 W 2,200 W 2,600 W 4,400 W 8,000 W

DELTA8.4-DSP 4x4 1,300 W 1,700 W

1 700 W

MODE: OFF

– – – –

3,400 W

MODE: OFF

DELTA13.4(-DSP) 4x4 1,300 W 1,700 W 2,600 W 3,800 W

3,400 W

MODE: OFF

– – 7,600 W

DELTA14.4(-DSP) 4x4 1,300 W 1,700 W 2,600 W 3,800 W 5,000 W – – 10,000 W

DELTA20.4(-DSP) 4x4 2,200 W 2,900 W 4,400 W 6,300 W 8,000 W – – 16,000 W

Optionen

Description

-DSP

2 channel amplifier: 2 IN – 2 OUT DSP build-in loudspeaker management

4 channel amplifier: 4 IN – 4 OUT DSP build-in loudspeaker management

DSP-Library

Unique, true-to-original Hoellstern

®

loudspeaker libraries for more than
25 loudspeaker manufacturers.
Including FIR filter and system-specific settings and free user settings.

Software Hoellstern

®

Konfigurator2 – for Windows and Macintosh OS.

AC mains input 180 VAC to 265 VAC, operative from 70 VAC

AC grid current draw

Highly efficient power supply and amplifier technology:
Halved power consumption with 10 A or 16 A of average current draw.

Size and Weight

Width: 19“ – Height: 2 RU – Depth: 30 cm (!)
Weight: 10 – 12 kg

✔

Extremely audiophile signal

amplification.

✔

Load stable – high-current capable

outputs.

✔

Unique, faithful loudspeaker libraries

with all system-relevant features.

Manual

DELTA6.2-DSP

DELTA7.2 DELTA7.2-DSP

DELTA8.4-DSP

DELTA12.2 DELTA12.2-DSP

DELTA12.4 DELTA12.4-DSP

DELTA13.4 DELTA13.4-DSP

DELTA14.4 DELTA14.4-DSP

DELTA20.4 DELTA20.4-DSP

Serial number:

1. Introduction

Dear audio friend and audio technician.

Congratulations on your decision to use Hoellstern amplifiers. First-class tools are a solid foundation for professional
audio productions.

The ASID GmbH located near Freiburg designs, produces and distributes the Hoellstern amplifiers. It is our
philosophy to supply top-quality audio products.

Hoellstern amplifiers present modern, efficient amplifier technology in combination with efficient, strong switching
power supplies. The technical dimensioning and the circuit design are based upon criteria from the aerospace and
automotive industries. Together with an uncompromising circuit layout and high-quality components the result is a
top-grade audio product. Only the quality of our products and the resulting customer satisfaction have the highest
priority for us.

Hoellstern amplifiers meet numerous requirements, from the viewpoint of a sound engineer and also of a buyer:

x Performance, sound, size and weight
x Features, operation and flexibility
x Reliability, stability of value, cost effectiveness

Please take your time to read the manual attentively prior to putting the unit into service. This way you will become
familiar with the technical details and use the amplifiers optimally. For permanent installations we ask you to solicit
further information from us if needed.

Please do observe all safety notes before bringing the unit into operation!

Please take care of your amplifiers, aspirate the air filters regularly and make sure the amplifiers are mounted
correctly. Every additional warming by 10 Kelvin will typically halve the service life of electronic components.

We wish you much success.

ASID GmbH

Page 2 of 20

1.1 General Information

Manual version 2.10 / 04 / 2015 for the Hoellstern amplifier models:

- DELTA 6.2-DSP

- DELTA 7.2 / DELTA 7.2-DSP

- DELTA 12.2 / DELTA 12.2-DSP

- DELTA 8.4-DSP

- DELTA 12.4 / DELTA 12.4-DSP

- DELTA 13.4 / DELTA 13.4-DSP

- DELTA 14.4 / DELTA 14.4-DSP

- DELTA 20.4 / DELTA 20.4-DSP

ASID GmbH © 2004 - 2015. All rights reserved. Hoellstern®, the iCVP® logo and combinations thereof and others
are registered trademarks; other terms, product names and logos are brands held by other companies and owners of
rights.

All information contained herein have been compiled to the best of our knowledge.
Specifications, dimensions and weights do not represent guaranteed features.
ASID GmbH reserves the right to changes which take the current state of the art into account.

Published by:

ASID GmbH
Eichstetter Str. 55
D-79232 March / Germany

Phone [phone]
Fax [phone]
email: [e-mail]

Internet: www.hoellstern.com
Internet: www.hoellstern.eu

Page 3 of 20

Table of contents

1. Introduction................................................................................................................................................................2

1.1 General Information..............................................................................................................................................3

2. Safety Notes...............................................................................................................................................................5

3.Mounting into a 19” Rack or a 19” Cabinet..............................................................................................................7

3.1 Ventilation of the Units..........................................................................................................................................7

3.2 Air Filters...............................................................................................................................................................7

3.3 Ventilation of Racks and Equipment Cabinets .....................................................................................................7

3.4 Important Mounting Instructions and Tips.............................................................................................................7

4.Wiring of the Audio Inputs.........................................................................................................................................7

4.1 Balanced Input Signals.........................................................................................................................................8

4.2 Unbalanced Input Signals.....................................................................................................................................8

5. Output Wiring and Damping Factor.........................................................................................................................8

6. Configuration.............................................................................................................................................................9

6.1 Connecting Channels 1 to 4 (amplifiers produced until 07/2011).......................................................................10

6.2 Connecting Channels 1 to 4 (Amplifiers produced from 07/2011)......................................................................11

6.3 Rear Panel Configuration Switches....................................................................................................................12

6.4 DELTA8.4-DSP amplifier configuration:.............................................................................................................13

6.5 DELTA 12.4(-DSP) configuration........................................................................................................................13

6.6 DELTA 13.4(-DSP) configuration........................................................................................................................14

6.7 DELTA 14.4(-DSP) Configuration.......................................................................................................................14

6.8 Rear side of DELTA6.2-DSP, DELTA 7.2(-DSP) and DELTA 12.2-DSP...........................................................15

6.9 Rear side of DELTA 8.4-DSP.............................................................................................................................15

6.10 Rear side of DELTA 12.4(-DSP).......................................................................................................................15

6.11 Rear side of DELTA 13.4(-DSP).......................................................................................................................15

6.12 Rear side of DELTA 14.4(-DSP).......................................................................................................................15

6.13 Rear side of DELTA 20.4(-DSP).......................................................................................................................16

7. Indicators and Controls..........................................................................................................................................17

7.1 Gain Controls......................................................................................................................................................17

7.2 LED Indicators....................................................................................................................................................17

8. Power Supply...........................................................................................................................................................18

8.1 Mains Supply and Power Supply with iCVP® Technology.................................................................................18

8.2 Operation on Generators....................................................................................................................................18

9. Technical Specifications.........................................................................................................................................19

10. Integrated Digital Loudspeaker Management (-DSP).........................................................................................19

10.1 Hoellstern Loudspeaker Library........................................................................................................................19

10.2 DSP Configuration, Hoellstern Software Konfigurator1 and Hoellstern Konfigurator2.....................................19

11. Terms of Guarantee...............................................................................................................................................20

11.1 Liability Declaration ..........................................................................................................................................20

11.2 Product Warranty..............................................................................................................................................20

12. Disposal.................................................................................................................................................................20

13. Conformity Declaration .......................................................................................................................................20

Page 4 of 20

2. Safety Notes

Before using the product, please read this manual attentively and follow all safety notes. Their purpose is to
keep the user safe and help avoid technical defects and consequential damages caused by incorrect
operation. Make sure teep this manual for future reference.

Caution:

The amplifier is a protection class 1 unit. While in operation, make sure the unit’s protective
conductor (earth) is connected properly. A missing protective conductor may cause
hazardous voltages to occur on the case and controls!

Caution

: Make sure all units of your system are grounded correctly to avoid the risk of an electric

shock!

Caution:

Never connect any output of an amplifier to an output, input or ground contact of any other
amplifier. Otherwise you will expose yourself to the risk of an electric shock or technical
defect.

Caution:

All connected cables must be laid out in such a way that they cannot be bruised by objects
or be stepped upon! Replace damaged cables at once, don't use them!

Caution:

Keep the unit away from dust, moisture, water and other liquids! If despite all care liquid has
got into the unit, immediately pull the mains plug to disconnect the unit safely from mains.
Contact ASID to consult about further measures. Do no longer use the unit under any
circumstances, as fire hazard or injury through an electric shock may result otherwise! For
additional safety the printed circuit boards and components are coated.

Caution:

Never open the housing, there are no serviceable parts inside the unit! Leave such works to
a qualified technician.

Caution:

Use only suitable cables with a copper cross section of at least 4 mm2to connect the
loudspeakers. Due to the high output power, fire hazard or injury through an electric shock
may result with an undersized copper cross section! Molten insulations can produce short
circuits, causing equipment or personal damages. The cables must guarantee a long-term
isolation voltage of at least 250 V AC.

Caution:

Use mains cables with a sufficient copper cross section of at least 1.5 mm2. For cable
lengths greater than 20 m, 2.5 mm

2

are advisable. Cable drums and the like must be

unwound completely, otherwise fire hazard or injury through an electric shock may occur!

Caution:

According to VDE regulations, the Neutrik PowerCON mains connector must not be hot­plugged nor pulled out hot! This is especially true under load. The PowerCON is not a plug­and-socket device designed in accordance with the VDE regulations against burn-up due to
possible spark gaps.
For greater safety and reliability all Hoellstern amplifiers feature an internal mains voltage
monitoring and will cut out almost with no delay in case of a cable interruption. Hence spark
gaps caused by disconnecting the mains supply will be avoided best or put out as quickly
as possible.

C

aution: No sensitive signal and data lines, transmitters and receivers must be laid out or built in

close proximity to the loudspeaker and mains cables. Persons with a cardiac pacemaker
must keep a distance of at least 3 m from loudspeaker and mains cables. Otherwise the high
currents (up to 125 A in speaker cables) and the associated magnetic AC fields may produce
malfunctions.

C

aution: Before connecting the units to mains voltage, make sure that the respective mains outlet

delivers the correct voltage and has a correct protective earthing conductor. This is
especially critical when working at different venues or with power generators. When
exceeding the permissible maximum input voltage, fire hazard or injury through an electric
shock may result!

Page 5 of 20

Note: In the following cases it will be necessary to return the unit to the manufacturer or to a

producer-authorised specialised company for inspection. You will find the contact data on
the manufacturer's homepage www.hoellstern.com.

- The unit was dropped or otherwise mechanically mistreated or damaged.

- The mains cable or mains plug was damaged.

- Objects or liquids have got into the unit.

- The device does not function as usual.

- The unit signals internal faulty conditions on the LED display.

Page 6 of 20

3. Mounting into a 19” Rack or a 19” Cabinet

All devices can be mounted into standard 19” cases (racks and cabinets). Screw the units into place using the two
mounting holes on each of the frontside rack ears. Use only screws with a large head diameter and locking washers.
Please contact us regarding the optional mounting of retainer plates on the back. Never use too long screws; these
might internally damage and destroy the electronics.

3.1 Ventilation of the Units

The amplifiers have a temperature-controlled forced air cooling. NOTE: The direction of the airflow is from front to
back. The fan speed is controlled depending on the internally measured temperatures. Make sure not to obstruct the
air influx and outlet when installing the units. Never use electronic devices in the warm airflow of the amplifiers since
it is hotter than the ambient temperature. For manual function control and during the power-up phase the fans will
momentarily run at a higher speed. Hoellstern amplifiers which offer several operating modes use different fan speed
curves depending on their operating mode and the potential power output.

3.2 Air Filters

The air filters are locked in place by hexagonal perforated steel spring plates. The easiest way to clean the filters is to
vacuum them while mounted. If the open-pore air filter is to be changed, pull the perforated steel plate off the front
panel aperture using a pair of pliers and a screwdriver. A replacement for worn-out air filters may be ordered from the
manufacturer.

A heavily soiled air filter will reduce the cooling capacity and may cause overtemperature. Never use the unit without
an air filter, otherwise there is a risk of the electronics becoming polluted. A malfunction may be the consequence.
Please replace faulty air filters immediately.

3.3 Ventilation of Racks and Equipment Cabinets

Equipment cabinets and 19“ racks must be adequately vented. The units may be stacked upon each other. The
housings do not serve as heatsinks.

3.4 Important Mounting Instructions and Tips

Protection of other units from thermal stress:

Do not mount other sensitive electronic devices in close contact with the top lids of the amplifiers. Due to the internal
warming the housing cover will also warm up. If the mains supply is disconnected immediately after high strains, this
will inevitably cause further warming up of the case lid. The heat will be dissipated to devices mounted in direct
contact, causing possible malfunctions or defects in those devices. In general it is advisable not to disconnect the
mains supply immediately after heavy stressful conditions for amplifiers, as the trailing fans will prevent an internal
heat build-up.

Protection from mechanical stress:

Screw two suitable aluminium angle sections laterally into the 19” cabinet which serve as sliding rails and contact
faces for the units. On these rails you can slide the units into place. Several units may be pushed in stacked upon
each other.

4. Wiring of the Audio Inputs

The audio input connections are made via XLR-3 connectors on the rear panel of the amplifier. Each audio channel
has a Neutrik full-metal XLR female socket and a full-metal XLR male socket for slaving the signal. The input signal
of the female XLR socket is internally directly wired through to the corresponding XLR male socket. The inputs are
balanced and wired as follows:

Page 7 of 20

4.1 Balanced Input Signals

With a balanced audio source pin 2 (hot) and pin 3 (cold) are used to carry the signals. Pin 1 is the common signal
and chassis ground. Always pay attention to a correct shielding.

4.2 Unbalanced Input Signals

If there is only an unbalanced audio source available, the audio signal must be put to pin 2 (hot). Pin 3 (cold) must be
connected to pin 1 (signal mass). Always pay attention to a correct shielding.

5. Output Wiring and Damping Factor

The output connections are made via Neutrik high-current SpeakON sockets. To keep the cable losses in the
loudspeaker cables low and to ensure safety, we recommend using a cable cross section of 4 mm

2

. Hoellstern
amplifiers are equipped with scoop-proof high-current SpeakON sockets which have a very low contact resistance of
typically 1milliohm per contact. For your own safety use original Neutrik connectors exclusively.

The best audiophile results and maximum sound pressure levels will be achieved through minimum cable resistance
values. The resistance is proportional to the cable length or inversely proportional to its cross section. Use therefore
preferably large copper cross sections and keep your cables as short as possible.

CAUTION:

All contacts of the SpeakON connectors are hot. Never connect the amplifier outputs with
any other outputs, ground or signals!

CAUTION:

A safe, fully insulated line must be used. When laying cables out in the open, use watertight
and UV resistant cable insulations. Please observe by all means the relevant national
guidelines and CE regulations!

CAUTION

: To avoid the risk of an electric shock, the amplifier should not be used if blank cable ends

are visible. The inputs and outputs must be wired only when the amplifier is turned off and
not connected to mains. Never touch the output voltages at the SpeakON connectors during
operation to avoid the risk of an electric shock!

CAUTIO

N: Use only suitable cables with a copper cross section of at least 4 mm2to connect the

loudspeakers. Due to the high output power, fire hazard or injury through an electric shock
may result with an undersized copper cross section! Molten insulations can produce short
circuits, causing personal or equipment damages.

CAUTI

ON: No sensitive signal and data lines, transmitters and receivers must be laid out or built in

close proximity to the loudspeaker and mains cables. The high currents (up to 120 A in
speaker cables) and the associated magnetic AC fields may produce malfunctions.

Page 8 of 20

6. Configuration

A Hoellstern DELTA 4-channel amplifier contains two identical amplifier modules. Module 1: C 1 / C 2 and module 2:
C 3 / C 4. Both modules are fed from a common power supply. A Hoellstern DELTA 2-channel amplifier contains one
amplifier module. Each amplifier module has two channels. Each amplifier module may be operated in bridge mode.
If on a 4-channel amplifier one module is operated in bridge mode and the other module in stereo mode, we have a
three-channel amplifier. If both amplifier modules are bridged, we have a two-channel amplifier.

Owing to special circuit technologies, Hoellstern amplifiers achieve almost double the output power at halved
impedance (load stable iCVP® technology). For this reason Hoellstern amplifiers can be used in a very flexible and
cost-efficient manner, and they sound excellent even at low impedance loads over the entire frequency range.

Via the terminal assignment of the SpeakON output sockets and the positions of the configuration switches on the
rear panel different operating modes can be configured. Each amplifier module has two Neutrik high-current
SpeakON sockets and a quad configuration switch. The contacts of the encapsulated toggle switches are gold-plated
for optimum contact safety and have a typical lifetime of 20,000 cycles.

Each amplifier module may be operated in one of the following modes:

Stereo: 2 channels with 2 independent inputs.

Mono: 2 channels mono parallel, with one input CH 1 or CH 3 resp. The other

input (CH 2 or CH 4 resp.) has no function.

Bridge: 1 channel in bridge mode, with one input CH 1 or CH 3 resp. The other

input (CH 2 or CH 4 resp.) has no function.

Exception: With models DELTA 14.4 and DELTA 14.4-DSP the CH3 / CH4 module has no Bridge /
Stereo configuration switch. The module always works in stereo mode. If you wish to work in
MONO mode, the channels must be slaved with short XLR cables.

Page 9 of 20

6.1 Connecting Channels 1 to 4 (amplifiers produced until 07/2011)

Channels 3 and 4 are connected just like channels 1 and 2. Only the pictured wiring options are permitted. The wiring
options are printed on the back panel of the unit.

Alternatively, in bridge mode connector C2 pin 2+/ 1- or connector C4 pin 2+/ 1- can be used.
(Compatible with amplifiers produced from 07 / 2011)

Page 10 of 20

6.2 Connecting Channel s 1 to 4 (Amplifiers produced from 07/2011)

Configuration Channels 1 and 2:
Only the pictured wiring options are permitted. The wiring options are printed on the back panel of the unit.

Configuration Channels 3 and 4:
Only the pictured wiring options are permitted. The wiring options are printed on the back panel of the unit.

Page 11 of 20

6.3 Rear Panel Configuration Switches

For configuration, each amplifier module has a quad configuration switch located on the rear panel. The individual
switches are labelled and have the following meanings (from left to right):

Channels C3 / C4:

MISC: Models DELTA 7.2 and DELTA 7.2-DSP: Labelled MISC:

No function, reserved.

Models DELTA 12.4, DELTA 12.4-DSP: Labelled SYM:
Configuration of operating mode and output power.

Models DELTA 8.4-DSP, DELTA 13.4, DELTA 13.4-DSP: Labelled ON:
Configuration of operating mode and output power.

Models DELTA 14.4, DELTA 14.4-DSP: Labelled ON:
Configuration of operating mode and output power.

Models DELTA 20.4, DELTA 20.4-DSP: Labelled ON:
No function, reserved.

BRIDGE: DELTA 8.4-DSP, DELTA 12.4, DELTA 12.4-DSP, DELTA 13.4, DELTA 13.4-DSP,

DELTA 20.4, DELTA20.4-DSP:
Lower position: Stereo mode, no bridge mode.
Upper position: Bridge / mono mode.

Bridge mode: Mind the correct pin assignment of the SpeakON sockets! Use the right

SpeakON sockets! A faulty pin assignment may cause 180° phase errors!
A faulty pin assignment may damage the unit.

DELTA 14.4, DELTA 14.4-DSP: Labelled ON:
Configuration of operating mode and output power.

Channels C1 / C2:

MISC: Selection of the serial communication interface:

Upper position: RS-232 interface active.
Lower position: RS-485 interface active.

BRIDGE: Lower position: Stereo mode, no bridge mode.

Upper position: Bridge / mono mode.

Caution: Mind the correct pin assignment of the SpeakON sockets! Use the right

SpeakON sockets! A faulty pin assignment may cause 180° phase errors!
A faulty pin assignment may damage the unit.

Channels C1 / C2 and C3 / C4:

GAIN: Lower position: Default gain setting of the respective channel is 26 dB in stereo

and mono mode and the associated gain control (front panel) at 0 dB
(right-hand stop).

Upper position: Default gain setting of the respective channel is 32 dB in stereo
and mono mode and the associated gain control (front panel) at 0 dB
(right-hand stop).

If the module is operated in bridge mode, another 6 dB must be added to the
basic gain because of the double output voltage of the bridged circuit.

Page 12 of 20

6.4 DELTA8.4-DSP amplifier configuration:

The DELTA8.4-DSP amplifier offers two different operating modes.

Configuration is made via a switch located on the left-hand rear panel between channel 3 and 4.

Impedance 4 channels Switch position

Operating mode

C1 C2 C3 C4 C1/2 and C3/4 bridged
8,0 1.300 W 1.300 W 1.300 W 1.300 W 2 x 3.400 W at 12 ohms ON
6,0 1.700 W 1.700 W 1.700 W 1.700 W ­4,0 - - - - ­2,0 - - - - -

C1 C2 C3 C4 C1/2 and C3/4 bridged Operating mode
8,0 850 W 850 W 850 W 850 W 2 x 3.400 W OFF
4,0 1.700 W 1.700 W 1.700 W 1.700 W ­2,7 - - - - ­2,0 - - - - -

All power specifications are measured in practical burst mode above certain total output s.

6.5 DELTA 12.4(-DSP) configuration

The DELTA 12.4(-DSP) amplifier offers two different operation modes. Configuration is done via a labelled switch
located on the left side of the rear panel between channels C3 and C4.

Impedance Channel Switch position

Operating mode

C1 C2 C3 C4 C1/2 and C3/4 bridged

8.0 600 W 600 W 600 W 600 W 2 x 2,200 W

OFF

Asymmetrical

current carrying

capacity

4.0 1,150 W 1,150 W 1,150 W 1,150 W 2 x 4,400 W

2.7 1,700 W 1,700 W 1,700 W 1,700 W 1 x 6,000 W at 2.7 ohms C1/2

plus

1 x 4,400 W at 4 ohms C3/4

2.0 2,200 W 2,200 W 2,200 W 2,200 W 1 x 8,000 W at 2.0 ohms C1/2

plus

1 x 4,400 W at 4 ohms C3/4

1.6 2,600 W 2,600 W 2,600 W 2,600 W -

1 4,000 W 4,000 W 2,600 W @ 1.6

ohms

2,600 W @ 1.6

ohms

-

Impedance C1 C2 C3 C4 C1/2 and C3/4 bridged

SYM MODE

Symmetrical current

carrying capacity

8.0 400 W 400 W 400 W 400 W 2 x 1,500 W

4.0 800 W 800 W 800 W 800 W 2 x 3,000 W

2.7 1,200 W 1,200 W 1,200 W 1,200 W 2 x 4,500 W

2.0 1,600 W 1,600 W 1,600 W 1,600 W 2 x 6,000 W

1.6 2,000 W 2,000 W 2,000 W 2,000 W -

1 3,000 W 3,000 W 3,000 W 3,000 W -

All power specifications are typical and measured in practical burst mode above certain total outputs.

Page 13 of 20

6.6 DELTA 13.4(-DSP) configuration

The DELTA13.4 (-DSP) amplifier offers two different operating modes.
Configuration is made via a switch located on the left-hand rear panel between channel 3 and 4.

Impedance 4 channels Switch position

Operating mode

C1 C2 C3 C4 C1/2 and C3/4 bridged
8,0 1.300 W 1.300 W 1.300 W 1.300 W 2 x 5.200 W ON
4,0 2.600 W 2.600 W 2.600 W 2.600 W 2 x 7.600 W at 5,3 ohms
2,7 3.800 W 3.800 W 3.800 W 3.800 W ­2,0 - - - - -

C1 C2 C3 C4 C1/2 and C3/4 bridged Operating mode
8,0 850 W 850 W 850 W 850 W 2 x 3.400 W OFF
4,0 1.700 W 1.700 W 1.700 W 1.700 W 2 x 6.800 W
2,7 2.500 W 2.500 W 2.500 W 2.500 W ­2,0 3.400 W 3.400 W 3.400 W 3.400 W -

All power specifications are measured in practical burst mode above certain total output s.

6.7 DELTA 14.4(-DSP) Configuration

The DELTA 14.4 amplifier offers four different operation modes. Configuration is done via two switches
located on the left side of the rear panel between channels C3 and C4.

Impedance 4-channel operation Switch Switch

C1 C2 C3 C4 A B

8.0 1,300 W 1,300 W 1,300 W 1,300 W ON ON

4.0 2,600 W 2,600 W 2,600 W 2,600 W

2.7 3,800 W 3,800 W 2,500 W @ 4 ohms 2,500 W @ 4 ohms

2.0 5,000 W 5,000 W 2,500 W @ 4 ohms 2,500 W @ 4 ohms

C1 C2 C3 C4 A B

8.0 1,300 W 1,300 W 1,300 W 1,300 W ON OFF

4.0 2,600 W 2,600 W 2,600 W 2,600 W

2.7 3,800 W 3,800 W 3,800 W 3,800 W

2.0 - - - -

C1 C2 C3 C4 A B

8.0 1,000 W 1,000 W 1,000 W 1,000 W OFF ON

4.0 2,000 W 2,000 W 2,000 W 2,000 W

2.7 3,000 W 3,000 W 3,000 W 3,000 W

2.0 4,000 W 4,000 W 3,000 W @ 2.7
ohms

3,000 W @ 2.7

ohms

C1 C2 C3 C4 A B

8.0 850 W 850 W 850 W 850 W OFF OFF

4.0 1,700 W 1,700 W 1,700 W 1,700 W

2.7 2,500 W 2,500 W 2,500 W 2,500 W

2.0 3,400 W 3,400 W 3,400 W 3,400 W

All power specifications are typical and measured in practical burst mode above certain total outputs.

Page 14 of 20

6.8 Rear side of DELTA6.2-DSP, DELTA 7.2(-DSP) and DELTA 12.2-DSP

6.9 Rear side of DELTA 8.4-DSP

6.10 Rear side of DELTA 12.4(-DSP)

6.11 Rear side of DELTA 13.4(-DSP)

6.12 Rear side of DELTA 14.4(-DSP)

Page 15 of 20

6.13 Rear side of DELTA 20.4(-DSP)

Page 16 of 20

7. Indicators and Controls

7.1 Gain Controls

Each amplifier channel has its own gain control on the front panel. In bridge/mono mode the C2 or C4 control has no
effect on the gain. The gain controls are controlled and analysed by microprocessors. A change in the position will
only be taken over with a short delay. Always let the rotary knob perceptibly latch in the desired position (21
positions). In-between positions are not permitted and useless. The first three positions counterclockwise from right­hand stop are equivalent to 0 dB attenuation, i.e. the basic gain (see 26 dB / 32 dB selector switch on the rear side) is
active. Every other position counterclockwise will reduce the gain. The left-hand stop is equivalent to mute (100 dB
attenuation).

7.2 LED Indicators

ON-STBY Green flashing: The amplifier is connected to a mains outlet and switched to

standby mode.

Green on: The amplifier is connected to a mains outlet and the amplifier

module is active (ON).

.
SIG Green on: A signal is present at the corresponding XLR audio input.

The display is filtered and reacts with a delay.

- 6, -3, 0 dB Level meter of the corresponding channels. The detection of the 0 dB full drive mark is done

without filtering and very precise. If the 0 dB peak value is exceeded for more than 10 µsec, this
will be digitally cached and indicated delayed on the display for one second. Compared to all
conventional analogue 0 dB meters, this 0 dB reading is much more sensitive and precise.

LIMIT Red on: The signal limiter is active. The gain of the corresponding channel is reduced.

With the limiting function active, a channel continues to amplify linearly without
any compression of the audio signal.

Indicates AC mains overload: As soon as the internal intelligent mains control recognises a
potential mains fuse overload, the limiters on all four channels will respond at once and the gain is
reduced. All four Limit LEDs will be lit. The typical current limit values of 16A automatic mains cut­outs (class B) will be observed.

HFLF Red on: A low frequency and / or high frequency audio signal with an excessive level is

present at the output. To protect the loudspeakers the level is limited at the
output. If a limit value is exceeded after a short waiting time despite active
limiting, the module will turn off completely for safety reasons.

TEMP TEMPERATURE

Red flashing: The corresponding module has reached a critical heatsink temperature and

the gain is reduced.

Red on: The heat sink temperature has further gone up despite level limiting and the

corresponding amplifier module switches to standby mode. After the heat sink
has cooled down, the module will automatically turn on again. Troubleshooting:
See chapters on filter cleaning, ventilation and mounting into 19” racks and
equipment cabinets.

CUR CURRENT

Red on: The output current of the amplifier module was exceeded. The module will switch

to standby for about 200 ms and then turn on again automatically. This procedure
may be repeated up to 4 times. If overcurrent should still persist, the amplifier
module will remain in standby mode. A quick OFF - ON using the standby switch
on the front panel – wait a few seconds – will allow another power-up of the
amplifier. Troubleshooting: Check all output channel assignments, check all
connected cables and loudspeakers and correct them, if necessary. See also
chapter on configuration.

MISC MISCELLANEOUS

Yellow on: Bridge mode active (Bridge switch in upper position).
Off: Stereo mode active (Bridge switch in lower position).
Flashing: The internal diagnose functions have detected an internal failure. The unit must

be returned to the manufacturer for service. Please contact ASID GmbH.

Page 17 of 20

8. Power Supply

8.1 Mains Supply and Power Supply with iCVP® Technology

The devices feature an active power factor correction circuit (PFC). Therefore the amplifier will burden the mains
supply almost like an ideal, purely ohmic load. This means that voltage and current flow are in phase. Only this way
you can draw maximum power from mains with almost no reactive power. Thus mains will be saved and the
automatic circuit breaker not unduly burdened. Furthermore, the mains input current is permanently controlled
internally by an intelligent microprocessor. So before an automatic mains cut-out can trip due to an excessive current
load, the output power of the amplifier will be reduced and then instantly raised again if permitted. However, during
operation this will not even occur with very low loudspeaker impedances and heavily compressed music material. All
limiter LEDs will light up together if the output power is reduced due to an imminent mains overload.

A reliable operation on 16 A (Class B) automatic mains cut-outs is permanently ensured, as long as the circuit
breaker complies with the current regulations. For systems which serve the needs of personal safety at least class C
circuit breakers must be used for safety reasons. A reserve will increase the system safety.

The unit can be operated already from 75 VAC and has a wide input voltage range. With high continuous output
powers a sufficiently stable mains voltage must be applied. The minimum and maximum values are printed on the
rear panel of the unit and listed in the chapter on technical data.

If other devices are connected to the same mains, make sure that the internal line resistance (in consequence of
undersized mains cables, cable drums etc.) is not too high. Otherwise it can happen that other loads connected
hereto will show malfunctions due to momentary mains voltage fluctuations. When using cable reels or other
extension cables, the cable must be unwound completely. It is advisable to use a minimum copper cross section of

2.5 mm2 . For greater distances you need to contact authorised and skilled experts.

As soon as the unit is connected to the mains voltage, it is in standby mode. Only after the ON / Standby switch (front
panel) is set to the ON position, intelligent protection circuits will perform a software-controlled check of all internal
conditions before the unit will turn itself on completely (boot procedure). After a few seconds the amplifier will be
ready for work and slowly increase the gain settings to the preset values.

8.2 Operation on Generators

When operating the amplifier on a generator, it must be taken into account that a high momentary mains current draw
may occur, depending on the connected loudspeakers, the operating modes (bridge / single-ended), the drive level of
the amplifier, the audio signal and the limiter settings of the signal controller. With high pulse-like output powers,
undersized generators (too small a gyrating mass and too feeble peak current capability) can be slowed down to a
halt. If this problem occurs and there is no other, more stable mains supply available, you may check two things as a
possible interim remedy:

a) Adjust the limiters (RMS and Peak Limiter) in the signal path to more sensitive settings and gradually lower the
maximum output voltage settings on the controller.

b) Use bridged channels (bridge mode) in single-ended mode. This will reduce the maximum output power to a ¼ of
the initial value, thereby also lowering the mains current draw. Caution: Mind the pin assignment of the SpeakON
socket!

Page 18 of 20

9. Technical Specifications

For technical specifications please visit our website www.hoellstern.com

or www.hoellstern.eu.

10. Integrated Digital Loudspeaker Management (-DSP)

All Hoellstern amplifiers are optionally available with a built-in digital loudspeaker management.

10.1 Hoellstern Loudspeaker Library

We offer comprehensive loudspeaker libraries for our Hoellstern amplifiers and configure them after consultation with
our customers. For further information please visit our website www.hoellstern.com

or www.hoellstern.eu and contact
ASID GmbH. The libraries are described and sorted by loudspeaker brands on the website. All DSP setups have
been carefully compiled. The Hoellstern setups emulate precisely their originals in terms of transit time, phase and
gain over the frequency. Likewise, the safety-relevant RMS and peak limiters have been carefully worked out.
Therefore Hoellstern amplifiers may be universally used, offering a manufacturer-independent “plug and play“
operation in combination with any given loudspeaker systems.

10.2 DSP Configuration, Hoellstern Software Konfigurator1 and Hoellstern Konfigurator2

The digital signal processing unit (DSP) is configured via the serial interface (RS-232 or RS-485) on the amplifier.

Page 19 of 20

11. Terms of Guarantee

11.1 Liability Declaration

ASID GmbH shall not be held liable for personal or physical damages (to loudspeakers, amplifiers or other
equipment) caused by careless operation, negligent installation, improper use or disregard of the manual.

When operating the amplifier in close proximity to HF transmitters (e.g. wireless microphones, mobile phones etc.)
acoustic and functional disorders may occur. Damages to the unit are improbable, yet cannot be excluded.

11.2 Product Warranty

Current warranty terms, see:

www.hoellstern.com

or

www.hoellstern.eu

Important: Please understand that prior to returning any units to ASID GmbH, a return number must be asked for in
writing, together with a description of the defect and the sales slip or an invoice copy enclosed. Otherwise we reserve
the right to decline acceptance.

12. Disposal

This is a b2b device in the sense of the Electrical and Electronic Equipment Act (ElektroG). The devices must not be
delivered to the collecting points of the public waste management authorities nor be put by them into the containers
which have to be collected by the producing companies free of charge. Consequently the producer shall not be
obliged to collect discarded appliances at collecting points. If appliances are to be disposed of, we recommend to
inform the producer despite this legal regulation.

13. Conformity Declaration

The appliance complies with the basic requirements laid down in the Council Directive on the Approximation of the
Laws of the Member States relating to Electromagnetic Compatibility (2004/108/EG).
The appliance must not be altered with regard to its physical and electro-mechanic properties. The instructions and
guidelines in this manual must be followed. The following standards are used:
DIN EN 55103-1:1996, E4 (Article 10 Supplement E, alternative measuring procedure: current transformers).
DIN EN 55103-2:1996, E4. The appliances have not been designed for living areas.
Serial number: Please refer to the cover sheet.

Accountable for this declaration is ASID GmbH, March / Germany. Date: January 20th, 2009.

Page 20 of 20

„The typewriter I‘m using contains
aluminium, probably from Jamaica or
Surinam, iron from Sweden, magnesium
from Czechoslovakia, manganese
from Gabon, chrome from Rhodesia
(today‘s Zimbabwe), vanadium from the
USSR, zinc from Peru, nickel from New
Caledonia, copper from Chile, tin from
Malaysia, cobalt from Zaire, lead from
Yugoslavia, molybdenum from Canada,
arsenic from France, tantalum from Brazil,
antimony from South Africa, silver from
Mexico as well as traces of other metals
from remote spots of the world.

The paint may contain titanium from
Norway; the plastic parts are made of
mineral oil which comes from the Middle
East and which has been cracked by
catalysts won from American mined rare
earths; they contain chlorine that was
separated by using mercury from Spain.
The moulding sand for the cast metal
frame comes from an Australian beach,
the machine tools for the production
contained tungsten from China, the coal
for the required energy came from the
Ruhr district – and the final product is
now consuming too many Scandinavian
spruce trees in the form of paper.”

Thus wrote Armory B. Lovins, Head of the
Rocky Mountain Institute in the USA in his
book „Openpit Mining” in the year 1973.
Already then he was aware of what has
been proven in many studies today:

There are products which use up
extremely many resources and
therefore cause serious environmental
issues in the end. Unfortunately, audio
power amplifiers also fall into this
category.

Copper which is used for transformers
and chokes may serve as the best
example:

For the extraction and production
of 1 kg of copper we have to spend

1.18 tons of materials and resources.

The extraction of copper (Cu) takes place
in several production phases. On the
mining level (mines) coppery ore is lifted
in surface (about 2/3) or underground
mining (1/3).

The mined crude ores have a very low
copper content between 0.5 % and 4 %.
This low copper content of the crude ores
necessitates a considerable use of energy
during production and refinement.

For every ton of copper an average of
219 tons of mining waste accrue.

During the processing stage the crude
ores are enriched to form concentrates
with a copper content of mostly 25 %
to 35 %.

This is followed by other beneficiation
processes and hence more consumption
of energy and resources and more
emissions to provide copper for the
production of e.g. transformers and
chokes.

Likewise, for the production of aluminium
and steel frightening figures could be
presented. To this we still need to add
the routes of transportation between
mining, extraction and processing which
also devour energy and are therefore
pollutive.

By these examples it becomes clear
very fast that digital high-performance
power amplifiers which don‘t require
heavy transformers and heat sinks and
which also have a small frame size, go
easy on the resources of our Earth.

The Hoellstern

®

audio amplifiers
help to keep the emissions and the
consumption of resources needed
for their production and during their
operation as low as possible.

Into the future with a good
conscience!

Environment

AUDIO AMPLIFIERS

Sales, distribution and production:

ASID GmbH

Eichstetter Strasse 55
79232 March / Germany

Phone [phone]
Fax [phone]

[e-mail]
www.hoellstern.com
www.hoellstern.eu