leema-acoustics Pulse III User manual

HANDBOOK
Leema Acoustics Pulse III Integrated Amplifier & DAC
PULSE III

Index PULSE III
Index
EC Declaration of Conformity .......................................................................................................................................2
Introduction .................................................................................................................................................................. 3
Safety Advice ................................................................................................................................................................ 4
Pulse Overview .............................................................................................................................................................. 5
Environmental, Made in the UK, Contact Us ............................................................................................ 5
Rear Panel ..................................................................................................................................................................... 6
Connections ................................................................................................................................................................. 7
Phono, CD, Tuner, Aux, AV Direct .............................................................................................................. 7
Tape In, OPT1, OPT2, SPDIF, USB, Tape Out, Preamp Out, Headphones .................................................... 8
LIPS Connection, Loudspeaker Terminals, Cables .................................................................................... 9
Controls ...................................................................................................................................................................... 10
Remote Control ........................................................................................................................................................... 11
Technical Discussion, DAC, USB CODEC .................................................................................................................. 12-13
LIPS ........................................................................................................................................................................ 14-15
LIPS codes, IR Codes .............................................................................................................................. 15
Audio Specifications ................................................................................................................................................... 16
WEEE Scheme ......................................................................................................................................... 16
1

EC Declaration of Conformity
In accordance with EN ISO 17070-1:2004
We Leema Electro Acoustics Limited
of Llanfair Caereinion
Welshpool
Powys
UK
in accordance with the following Directive(s): 2006/95/EC The Low Voltage Directive 2004/108/EC The Electromagnetic Compatibility Directive
hereby declare that: Equipment Hi-Fi Integrated Amplifier Model Name Pulse III
is in conformity with the applicable requirements of the following standards
Standard. No. Name International Equivalents
BS EN60065; 2002 Electrical Safety Requirements EN60065; 2002 / IEC60065; 2001
BS EN 55020; 2002 EMC Immunity EN55020; 2002 / CISPR 20; 2002
BS EN 55013; 2001 EMC Emissions EN55013; 2001 / CISPR 12; 2001
BS EN 61000-3-2; 2001 EMC Limits for Harmonic Emissions EN61000-3-2; 2000 / IEC61000-3-2; 2000
BS EN 61000-3-3; 1995 EMC Limits for Voltage Fluctuations EN61000-3-3; 1995 / IEC61000-3-3; 1994
I hereby declare that the equipment named above has been designed to comply with the relevant sections of the above referenced specifications. The unit complies with all applicable Essential Requirements of the Directives
and Standards.
Signed by: .................................................................................................................................................
Name: Mallory Nicholls
Position: Technical Director
Done at: Leema Electro Acoustics Ltd.
On: 23/6/2010
Declaration of Conformity
PULSE III
10
2

Introduction
Congratulations on your purchase of a Leema Pulse III amplifier.
The Leema range of products has been painstakingly engineered in the United Kingdom to offer genuine state-of-the-art
performance.
Partnered with suitable equipment, Leema amplification will provide audio performance far beyond that of competitors and
will equal or better the performance of products costing many times their purchase price.
A notable feature of all Leema amplification is incredible bass power and control, due to massive current capability,
together with superb clarity and finesse in the upper frequencies with stunning realism in the midband.
Purchasers should read and follow this instruction manual, paying particular attention to the user installation and safety
advice section.
This manual has been written to enable you to achieve the very best performance and maximum listening pleasure from
your investment.
We wish you many years of pleasurable listening... Move Your World!
With best regards
The Leema Team.
Introduction PULSE III
3

Warning
PULSE III
VERY IMPORTANT
Before connecting your new Leema amplifier to the rest of your system, please ensure that the loudspeaker cables are
correctly and firmly attached to the binding posts on the rear of the unit. All required sources should also be connected
BEFORE inserting the mains power lead and powering for the first time. Although the Pulse III amplifier has short-circuit
protection, shorts should be avoided to reduce the stress on the amplifier.
User installation and safety advice
Please ensure that the mains voltage of your new Pulse III amplifier is correct for your region. The setting is displayed on a label
below the mains power inlet. The mains voltage setting is not user adjustable, therefore the amplifier must be returned to the
manufacturer if any changes are required.
Ensure the mains supply is switched off at the wall socket, or unplugged before installing or moving the amplifier.
Do not use near water, for example do not place a potted plant on top of the unit or allow drinks to be placed near the unit. If
liquid is spilt in to the cabinet, remove the mains lead from the wall immediately. The amplifier should then be returned to your
dealer for safety testing before re-use. Failure to do so may result in electric shock or even fire! Do not use the amplifier in
damp conditions, e.g. outside of the house.
Keep away from direct sunlight and other heat sources and ensure adequate ventilation around the amplifier to maintain
proper cooling. Units MUST NOT be stacked directly on top of each other.
Never attempt to open the cabinet. There are no user adjustable parts inside and doing so will invalidate the amplifier’s
warranty.
In the event of an electrical storm, remove the mains power lead from the wall outlet.
4

As with all high-powered amplifiers, high voltages can occur at the output binding posts. Loudspeaker connection should
only be carried out with the unit switched off.
Pulse III overview
The Leema Pulse III is a high power output, microprocessor controlled, stereo integrated amplifier and high-performance
DAC. It is capable of class-leading performance at the heart of an audiophile stereo system, but thanks to the LIPS (Leema
intelligent protocol system) interface, it can also be the centre of a stunning home cinema or surround music system. Each
component in the system dynamically configures in real time depending on the requirements of each input source. The
microprocessor gives an unprecedented degree of sophistication, making Leema products easy to use for all the family. No
longer will only one member of the family know how to play a CD or watch a movie. The built-in intelligence learns your
preferences without menus or confusing options.
Environmental Issues
Leema operates a 100% recycling program. All waste materials generated as part of the manufacturing process are
recycled via a licensed specialist company. Although Leema electronics operate in standby mode as opposed to being
fully switched off, the power drain has been optimised to a negligible level. We do not recommend leaving our amplifiers
permanently powered on. All Leema amplifiers have been designed to attain full operational specifications and sound
quality within a few minutes of switch-on.
Made in the UK
Leema electronics are designed and manufactured in the UK.
Contact Us
Leema may be contacted via our website: www.leema-acoustics.com or by telephone: [phone]
Overview PULSE III
5

Rear Panel
PULSE III
‘LIPS’ connectors
This allows
communication between
various Leema system
components.
Loudspeaker Outputs
The loudspeakers connect here.
Ensure correct polarity:
Red terminal is +, Black terminal
is -.
WARNING:
Do not make connections with
unit connected to the mains
supply.
PRE-AMP Output
This output may be
used for bi-amping or
for bass extraction
when used with a
Leema Corvus.
Analogue Inputs
When a Pulse III is used in a stereo
system, inputs CD, TUNER and AUX,
may be used to connect stereo
analogue sources.
If the Pulse III is part of a multi-channel
system, CD, TUNER and AUX are used
to connect stereo-only sources.
AV DIRECT
The AV Direct input is intended for
connection of an AV processor or similar.
WARNING:
Any source connected here MUST have
it’s own volume control. When the AV input
is selected, the volume level is preset. If a
fixed level source is connected here e.g. a
CD player, the resulting volume level will
be extremely high.
TAPE Input and Output
A tape recorder or PC audio card
may be connected here. The
tape output will be the current
input unless tape is selected. In
this case the tape output will be
muted to avoid audio feedback.
Power Inlet
Ensure that the
specification indicated
below the connector is
correct for your area.
This will normally
either be 230VAC or
115VAC.
6
Separate inputs are
provided for moving magnet
and moving coil cartridges.
The desired input is selected
with a small switch between
the input sockets.
PHONO Inputs
AUX and MP3 Input
The AUX input is also wired to a
front panel socket for use with
MP3 players etc. Do not connect a
source to the AUX and MP3 inputs
simultaneously, as distortion will
result.
DIGITAL connectivity
Three inputs to the 24 bit
192kHz DACs are provided,
along with a USB connector
for use with a computer.

Connections PULSE III
Connections
Analogue Input connections
PHONO MM/MC> Separate inputs are provided for moving magnet and moving coil cartridges. The required input is
selected by using the small toggle switch between the inputs.
CD> The Pulse III’s CD input should be connected directly to the analogue outputs (usually marked left/right and colour
coded white/red) of the CD player.
TUNER> The Tuner input should be connected directly to the analogue outputs (usually marked left/right and colour coded
white/red) of the TUNER.
AUX> The Pulse III's AUX input can be connected directly to any line level analogue stereo outputs. Some devices such as
MP3 or hard disk based portable players have a comparatively low output which will require the Pulse III’s volume control to
be set at a higher position than would normally be required. This input is duplicated on the front panel. Do not connect the
front and rear inputs simultaneously.
WARNING: The AV DIRECT input must not be used with sources that are not equipped with an independent volume control
e.g. most CD players and DVD players. This input is designed to be used only with an external surround sound processor that
has an independent volume control.
AV DIRECT> The AV DIRECT input is provided for those using a dedicated external multi-channel processor equipped with a
volume control. Sources with fixed output levels such as CD and DVD players, MUST NOT be connected here. When AV is
selected, the volume setting defaults to a low level and then slowly rises to a pre-set unity gain point.Great care should be
taken when using the AV DIRECT input since an excessive volume level could easily result. However unlike other systems, the
volume control on the Leema system is still active and can be adjusted away from the pre-set point as a safety feature.
7

Selecting another input on the Pulse III and then re-selecting the AV DIRECT input, will reset the unity gain point.
TAPE> The Pulse III’s TAPE input should be connected directly to the analogue outputs (usually marked left/right and colour
coded white/red) of a recording device such as a tape machine or PC audio card.
DO NOT connect any available digital outputs from the source player to the input terminals of the Pulse, as damage to the
speakers is likely to occur.
Digital connections
OPT 1> This input may be connected to digital optical outputs carrying a SPDIF (PCM) stereo data stream, such as satellite TV
boxes etc. Ensure that the data stream is not multi-channel, such as AC3. The DAC can decode all data rates up to
24bit/192kHz, however 176.4kHz is not supported.
OPT 2> As OPT1.
SPDIF >This input may be connected to digital coaxial outputs carrying a SPDIF (PCM) stereo data stream, such as satellite TV
boxes etc. Ensure that the data stream is not multi-channel, such as AC3. The DAC can decode all data rates up to
24bit/192kHz, however 176.4kHz is not supported.
USB >A computer may be connected here for playback or recording. The USB codec supports formats up to 16bit/48kHz. It
may be used for streaming playback or for recording the digital or analogue inputs.
Output connections
TAPE OUT> Any input selection other than TAPE will automatically be fed to the tape record output sockets. The volume
control has no effect on the record output level. When TAPE is selected as an input to the amplifier, the tape record output
feed is disconnected to prevent feedback. The tape input and record output are also suitable for other recording formats, for
example MP3 devices, mini disk recorders, CD-R disk recorders or even Hi-Fi VHS.
Connections
PULSE III
8

PRE OUT> A pair of outputs are provided which mirror the selected input e.g. CD player or tuner. These outputs are controlled
by the Pulse III's volume control and can be used for a variety of uses. Examples include feeding an amplifier in another room
for a simple multi-room system, or as a line level feed to a subwoofer. They can also be used for bi-amping, where a Pulse III is
used to drive the tweeters in the loudspeakers and an additional amplifier is used to drive the woofers. This offers an increase
in clarity by reducing intermodulation distortion. The loudspeaker no longer draws bass current from the amplifier feeding the
tweeter, resulting in cleaner high-frequencies etc. The loudspeakers must be suitable for bi-amping, this is normally the case
where there are two pairs of binding post connections available on the rear of the loudspeaker cabinets. When bi-amping, it
is vital to remove the bridging links from the connection panel on the rear of the speakers, otherwise the outputs of the two
stereo amplifiers will be connected together, which will result in considerable damage. If you are considering bi-amping,
please contact your dealer or Leema Electro Acoustics Ltd. for advice.
HEADPHONE OUT> A headphone output is available on the front panel. The output uses a 3.5mm mini-jack as found on
personal stereo headphones. Headphones should have a minimum impedance of 32 ohms. When this output is in use, the
loudspeakers are muted. Take care to reduce the volume level before removing the plug, as high volume level from the
speakers may result. It is advisable to unplug headphones before powering down the amplifier. Never wear headphones
while powering down the amplifier, as noise may be produced in the headphones as the power supplies drop.
LIPS connection
LIPS cables are directional and have one black end and one red. If Pulse III is controlling other units, the black connector
should be plugged in to either LIPS socket on Pulse III and the red connector plugged in to the next component. If Pulse III is to
be controlled, the black connector is connected to the master device and the red connector is plugged in to either LIPS
socket on Pulse III.
Loudspeaker terminals
There are two pairs of shrouded loudspeaker terminals on the rear panel, one pair for the left loudspeaker and one pair for the
right loudspeaker. They are designed for 4mm banana type plugs.
Connections PULSE III
9

Cables
Never underestimate the importance of good quality speaker cables, bell wire or lighting flex will simply not do. The higher
the system resolution, the more easily the differences between cables can be discerned. Leema recommend the use of
high quality bi-wire cables with your new amplifier to ensure optimum fidelity.
Front panel controls
Control is via a navigation style button cluster on the front panel. The navigation cluster consists of an up, down, left, right and
centre (standby) button.
Standby button
The blue light in the centre of the standby button is illuminated if the unit is in standby mode. Pushing the standby button once
or pressing the power button on the remote control will turn the unit on.
Source selection switch
Pressing the left or right buttons will cycle through the amplifier’s input sources and set the volume to an initial low level. When
AV Direct is selected, the volume slowly fades up to a pre-set unity level. The volume can be manually overridden at any time
by pressing the volume buttons or by pushing any of the buttons on the remote control.
Volume control
The up and down buttons control the volume via a Burr Brown precision attenuator under microprocessor control. This
method of volume control permanently ensures the highest fidelity without the gradual degeneration of conventional
motorised volume controls. The volume control has no effect on the tape-output, but does control the pre-out volume.
Note: Small clicks in the audio during volume changes are normal.
Controls
PULSE III
10

Remote control
Power
The power button (small red button) turns the unit on from standby or reverts to standby from
power on. When powered on, the unit initialises then, if applicable, the previous input selection
will be restored and the volume will fade up to a low level.
Mute
Pressing the mute button once while the system is playing will cause the volume to rapidly fade
to zero - MUTE is then displayed. A second push of the button will restore the volume level.
Input
The input up and down buttons cycle through the ten available input sources one-button push
at a time. The audio mutes for a fraction of a second between selections.
Volume
Two buttons, one for up and one for down, control the volume. Short presses on the volume
buttons will change the volume in small increments. Press and hold the volume up or down
buttons to smoothly raise or lower the volume.
Remote control PULSE III
11

Technical Discussion
Topology
Starting with the pre-amp and control stage, input selection is performed by gold over silver contact relays under control of
the microprocessor. The audio is then buffered by audiophile quality OP275 amplifiers in order to present the Burr Brown
precision attenuators with a low impedance drive signal. Next, the controlled signal passes to the class B power amplifiers,
the class A headphone amplifiers and to the pre-amp outputs.
The power amplifiers use a well established topology comprising differential input stage, class A voltage amplifier stage and
class B output stage. Each stage is highly optimised following the general teachings of design guru Doug Self, with notable
additions drawn from our own design research.
Each output stage uses a class A driver stage and a pair of very high performance output transistors incorporating integrated
thermal feedback.
The amplifier sections use multi-slope over-current protection in addition to thermal shutdown and fault monitoring.
After distortion measurement, the square wave performance of an amplifier is the ultimate timing test. A look at the square
wave performance of Pulse is testament to the time domain performance of the design. Apart from the gentle rounding of
the corners caused by amplifier input bandwidth filtering, the square wave response is virtually perfect and has no overshoot
or ringing. On the subject of ringing, if the amplifier is tested in to a load including a capacitive element, inaccurately trying to
simulate an electrostatic loudspeaker, ringing will be observed at the output in response to transient signals. In fact, this
ringing is not caused by the amplifier. It is simply the resonant combination of the amplifier output inductor and load
capacitance. No notice should be taken of any test reports including the level and makeup of this ringing, as the results are
totally dependant upon load type and applied stimuli.
Topology
PULSE III
12

DAC
The high-performance DAC uses a class leading Wolfson digital receiver in conjunction with Leema’s usual choice of Crystal
CS434x DAC. The DAC is followed by analogue filters which are optimised for time, as well as amplitude, performance.
The DAC offers 24bit/192kHz performance with excellent audio quality and very low jitter.
USB CODEC
The USB connection uses a Burr-Brown CODEC to encode and decode the USB data. Playback data is passed, in the digital
domain, to the Wolfson receiver in the DAC section for playback, thereby offering the same audio quality as an SPDIF input of
comparable data rate.
The resulting amplifier has the following characteristics:
Low noise
Very low distortion, typically better than class leading class A designs
High output current delivery
Low output impedance
Fast and detailed yet silky smooth audio presentation
High robustness and reliability
Topology PULSE III
13
Pulse III power-amplifier 1KHz
Square Wave performance

The following section is intended for installers, system integrators and third party manufacturers.
What is LIPS?
LIPS or Leema Intelligent Protocol System, facilitates communication between various items in a Leema audio system. It
allows units such as Pulse III and Tucana, to control other items in a chain. Leema’s 5.2 surround system is a good example,
where a Tucana controls a Hydra and Corvus. Key information including volume level, input selection and power control is
passed through the bus enabling other units to operate in synchronisation. Intelligence is added within each receiving unit,
for example, a Hydra installed as part of a surround system ‘knows’ that it won’t be required when listening to a stereo source
such as CD. Therefore, when the Hydra ‘sees’ the CD input, it powers itself down.
Each Leema unit can be controlled via the LIPS bus. Controlling a Pulse III externally for example, enables it to be used within a
home automation system.
LIPS Specifics
The LIPS bus is driven by an open-drain output. Leema can supply a full RS232 interface if required. The communication
standard follows the common RS232 format of No Parity, 8 data bits and 1 stop bit. The baud rate is 38400.
LIPS Packets
Each communication on the LIPS bus contains a packet of four data bytes as follows:
First a header is sent with a value of 255. This alerts the receivers to incoming data.
Next, a command header is sent. For a volume command, this would be 40. (see below for details).
Next, a value relating to the command is sent. For volume this would be 0 to 248.
Finally a tail byte is sent with a value of 0.
LIPS
PULSE III
14

LIPS codes
Pulse III IR codes
Format = Sony 12 bit
IR DEVICE = 16 (Amplifier)
IR Commands:
0 = Phono, 1 = CD, 2 = Tuner, 3 = AV Direct, 4 = Aux, 5 = Tape, 6 = USB, 7 = OPT1, 8 = OPT2, 9 = COAX SPDIF
16 = INPUT UP, 17 = INPUT DOWN, 18 = VOLUME UP, 19 = VOLUME DOWN, 20 = MUTE TOGGLE, 21 = POWER TOGGLE
For further information, please contact Leema Technical Support.
LIPS PULSE III
15

Audio Specifications
Power Output: 8 ohms: 80 Watts RMS per channel, 4 ohms: 150 Watts RMS per channel
Minimum load impedance: 4 ohms.
Output Current: greater than +/- 12 Amps
Frequency response +0/-3dB @ 1W: 5Hz - 80KHz
Noise (A weighted, volume control minimum): -98dBm
Signal to Noise ratio (A weighted, ref: 150 Watts RMS 4 ohms): -102dB
THD (10 Watts RMS 4 ohms, 1KHz): 0.008%
THD (Max output before clipping, 4 ohms, 1KHz): 0.008%
Maximum DC offset: +/- 15mV
Output Impedance: 0.04 ohms Damping Factor (8 ohms): 200
Sensitivity for Moving magnet input: 4mV RMS, for Moving coil input: 500uV RMS
Sensitivity for maximum output (CD input): 565mV RMS
Sensitivity for maximum output (other inputs): 311mV RMS
RIAA accuracy: +/- 0.2dB 20Hz-20KHz
DAC: 24bit/192kHz with low jitter receiver. USB: 16bit/48kHz Burr-Brown CODEC
Specifications subject to change without notice.
WEEE Scheme
Audio Specifications
PULSE III
16
Disposal of Electronic Equipment in the European Union and other countries with collection procedures:
The wheelie bin symbol on this product indicates that it shall not be treated as household waste. It should be
disposed of via a collection point for the recycling of electrical and electronic equipment. Leema is fully
registered under WEEE/HK 0757 ZX

Leema Electro Acoustics Limited
Unit K, Henfaes Lane, Welshpool, Powys, SY21 7BE, UK
Tel/Fax: [phone] email: [e-mail] Web: www.leema-acoustics.com