Electrocompaniet EC4.6 User Manual

EC 4.6 REMOTE CONTROLLED

BALANCED LINE PREAMPLIFIER

Owner’s Manual

WARNING: To reduce risk of fire or electric shock, do not expose this appliance to rain or m oisture. Verify
line voltage before use.
Do not remove cover. No user serviceable parts inside. Refer ser vicing to qualified
service personnel. The warr anty in void if the product is tampered with b y non authorised
personnel. Use only authorised Electrocompaniet service station.

Welcome to the world of Electrocompaniet
We sincerely thank you for selecting an amplifier from Electrocompaniet. We hope you will

enjoy years of listening pleasure and true high end musical performance from your audio
system. Kindly read this owners manual to familiarise yourself with the set before
operation.

The Electrocompaniet Story
Electrocompaniet was founded in 1973 in Oslo, Norway, to manufacture an amplifier
designed by Per Abrahamsen. The design were based upon a new approach to transistor
amplifier design developed by Dr. Matti Otala and Jan Lohstro.

It had long been recognised that transistor amplifiers had a characteristic sound that many
audiophiles and music lovers found unnatural.
Dr. Otala and Mr. Lohstro analysed transistor amplifiers to determine what actually created
the “transistor sound” in general transistorised designs. The results of their innovative
design work were incorporated in the first Electrocompaniet design, the legendary 25 watt
amplifier.

This product were the first commercial transistor amplifier to use this new design approach,
and the amplifier was immediately recognised as dramatically more musical sounding than
any other transistor amplifier. The same design philosophy, has been constantly updated by
additional research and development. This philosophy form the basis of all the current
Electrocompaniet Ampliwire and Preampliwire Dual Mono Balanced designs.

Electrocompaniet have always given extensive listening test of all it’s designs the highest
priority. Every product designed by our engineers must meet the varied and exacting
standards of the listening panel, carefully selected to represent a cross section of musical
taste and experience. Electrocompaniet designs go back and forth between the design
laboratory and the listening panel until both engineers and listeners are completely
satisfied, and ensured the that the design has met it’s technical and sonic objectives.

All Electrocompaniet products are handmade by highly skilled technicians, and extensively
tested for maximum performance and reliability.
Final adjustments are made only after an extended period of operation to insure the best
possible performance under conditions similar to those of actual use.
Electrocompaniet Ampliwire and Preampliwire are sold in more than 25 countries , provid­ing the ultimate listening pleasure to dedicated music lovers world-wide.

The design features of Preampliwire EC4.6

After the Electrocompaniet 25 watt amplifier had established a new standard for transistor
amplifiers, research was undertaken to find ways to make the amplifier even better, and to
extend its highly musical sound quality to more powerful amplifier designs. The engineers at
Electrocompaniet were not satisfied by only reducing the commonly recognised types of
distortion to low levels. They recognised that distortion appears in many forms, and that
distortion was still audible in listening tests even when conventional categories of distortion
were at astonishingly low levels.

Traditionally, designers increased feedback to make a larger portion of the output signal
control the amplifiers response. Our listening tests showed us that simply applying more
feedback was not the answer. In fact, as one kind of distortion went down, other parameters
would be adversely affected, leading to an overall degradation of sound quality. We knew
that the other conventional design approach of eliminating feedback completely was not the
answer either, because this would cause high distortion levels, and as a result would
produce a “woolly” sound.

The answer to the dilemma was found in a novel approach to feedback theory. We
developed a feedback concept that allowed local feedback to be applied around individual
stages of the amplifier circuit. This approach allowed us to avoid the sonic disadvantages of
overall feedback from output to input. The concept was further developed to reduce phase­and interphase distor tion between stages of the amplifier as well. We were able to concent­rate the loop feedback on the stages of the amplifier where it resulted in audible
improvement.
Stability margins were also expanded because feedback no longer affected the frequency
response. The use of this concept of individual gain blocks - complex in design but simple
in function - allowed us to reduce distortion to minute values in all the products.

The various amplifier stages are divided into two separate sections or gain blocks. The input
block is a transconductance amplifier without overall feedback. This avoids large output
voltage being fed back to the input, and mixed with the minute input signal. The output block
is a transresistance amplifier with parallel feedback. This is done to prevent higher
frequencies than the feedback loop can handle, from entering the loop. An approach like
this will prevent Transient Inter modulation Distortion ( TIM ) and Slewing Induced Distortion
(SID), eliminating the need for an extremely wide bandwidth.

All stages work in Class A with an efficiency of less than 0,1%. The power supply of the
EC-4.6 consists of a 50 VA toroidal transformers , and 10.000 micro farad reservoir divided
into ten 1000 micro farad capacitors, with separate regulator for each stage and channel.

Unpacking the Preamplifier:

Immediately upon receipt of the preamplifier, inspect the carton for possible damage during
shipment. If the carton is visibly damaged, a claim must be filed with the carrier as soon as
possible.
Unpack the unit carefully, and please do remember to save all packaging materials for
future shipment. The carton and packaging have been designed to offer the safest possible
protection when transporting your preamplifier.

The content of the carton is as follows:

1 pcs Electrocompaniet Preampliwire EC4.6
1 pcs ECT 1 remote control handset*
1 pcs AC power cord
1 Owners Manual

* ( Optional with or without remote)

Connecting the EC 4.6
Connecting to mains

Check that the mains voltage printed on the rear panel of the preamplifier corresponds with
the line voltage in the territory were you intend to use your preamplifier.

How to avoid damages

A good operating practice is to turn off all equipment before any connections or
disconnection’s are made. Do not under any circumstances connect or disconnect
equipment when power is turned on. If you insist on connecting or disconnecting while
power is turned on, you should be aware that the design of the RCA plug generates a large
transient when inserting the plug. This could damage both the speakers and the power
amplifier.

The rear panel

The rear panel of the Preampliwire EC 4.6 contains all input and output connectors. The
printed rear panel clearly indicates the function of each connector.

Single RCA input operation
The single end RCA inputs will work with any line level source. Simply connect the RCA
plugs from the source to the RCA socket you intend to use for that source. Switch the input
selector on the frontpanel to the position corresponding to the input you have chosen.
Balanced XLR input operation
The balanced mode can only be used if the source has a balanced output. In order to use
the balanced XLR input, connect the XLR plugs from the source to the XLR socket. Switch
the input selector on the frontpanel of EC 4.6 to CD balanced mode.

Connecting to the power amplifier:

Single-ended (normal) output and operation

Use the + RCA on right and left channel for connection to the power amplifier.
Balanced XLR output and operation

The balanced mode can only be used if the power amplifier has a balanced input.
Use an XLR interconnect with GND on pin 1, + on pin 2 and - on pin 3.

Balanced RCA output and operation

The balanced mode can only be used if the power amplifier has a balanced input. Be sure
the power amplifier is turned off. Use 2 single (1 stereo) interconnect cables from the
preamplifier to the power amplifier, connecting + and - outputs from the preamplifier to the
+ and - inputs of the corresponding channel on the power amplifier.
Make sure the + and - are not interchanged, as this will cause the system to operate out of
phase, with very poor bass response as a result.
NEVER use shorting plugs on any output terminal i.e. Rec. out or main out.

How to avoid noise problems
The EC 4.6 preamplifier contains circuitry that may be sensitive to magnetic fields. The unit
should be placed well away from transformers etc. Care should also be taken in routing all
signal cables. Do not run signal cables in parallel with speaker or AC cables ( mains).
Keep cables as short as possible.
If the unit is placed on top of a power amplifier, leave at least 4" ( 10cm) of space between
the two units.

Switches and controls

The power on/off switch is located in center of the face plate. This unit is equipped with
separate record and listen switches. It is possible to listen( for instance) to a CD while
recording another source - for instance a tuner. The two rotary switches are located on the
left half of the faceplate.The right half of the faceplate contains the volume and balance
controls.The volume and balance controls can be remotecontrolled via the ECT 1
handset.(Volume up/down and balance left/right.)

Operating instructions:
How to turn on your system
You should always turn on your equipment in this order: Signal source devices (CD, tuner,
etc) and preamplifier are turned on first. Allow 30 seconds of preheating before you turn on
your power amplifier.When turning your system off, you should start by switching off your
power amplifier, then the preamplifier, and finally your signal source devices

Warning:
The preamplifier will be warm.

Due to the high class A operating point used in the Electrocompaniet design, it is normal
that the preamplifier feels warm. Proper ventilation will be needed, and the preamplifier
should not be covered in. A good rule is to allow 1 - 2 inches of air sideways, and 2 - 3
inches above the preamplifier.

Service Policy:

When service is needed

Your dealer will have all relevant information about the service centers in your area, and will
ensure that your unit is serviced without delay. It is our general policy to have your
preamplifier returned to you within 5 working days. This is an average time, and could vary
locally, depending on the work load at the ser vice center.
If, for some reason, there are no service facilities available in your country, please ship the
preamplifier to the following address:

ELECTROCOMPANIET AS

BREIVIKVEIEN 7

N-4120 TAU, NORWAY

FAX [phone]

E-mail : [e-mail]

You are responsible for all shipping charges, insurance, re-importation to your country, and
duty arrangements. When shipping a product to the factory for service, always include the
following:

1) Sales slip or other proof of purchase if repair is claimed under
warranty.

2) Proforma invoice with value of the goods, stating “returned for repair”

3) An accompanying letter describing faults, symptoms, or problems with
the preamplifier

4) Always ship the preamplifier in its original carton and packaging
material to prevent damage in transit.

Electrocompaniet will not accept responsibility for any damage caused in transit, no matter
how ever caused.
If you require further information concerning the preamplifier operation, or if you have any
questions related to service, please do not hesitate to contact your dealer or national
Electrocompaniet distributor.

Technical Specifications EC 4.6
The following technical data were measured on randomised test objects and are typical

data. All measurements are made with the following equipment:
Distortion analyser: Tektronix AA501

Oscilloscope: Tektronix 468
Oscillator: Tektronix SG505
Frequency counter: Rascal 9838
Phase meter: Hewlett Packard 3575A

Preamplifier section
Single ended operation (gain) 0 dB
Balanced operation (gain) 6 dB
Input impedance 50 kOhm
THD single ended (1 V in / 1 V out) < 0.0013 %
THD balanced (1 V in / 1 V out) < 0.0007 %
Max. input > 10 V RMS
Channel separation (1 V output, 1 kHz) > 90 dB
Output impedance 100 Ohm
Max. output Single ended 8 V RMS
Max output Balanced 16 V RMS
Output noise 400 Hz - 30 kHz input shorted

Single ended : 5 µV
Balanced : 10 µV

Signal / noise > 100 dB
Frequency response 10 Hz - 100 kHz 0.4 dB

Power consumption (no load or signal) 15 W
Dimensions

Width 483 mm / 19 inches
Depth 240 mm / 9.5 inches
Height 70 mm / 2.8 inches
Weight5 kg. / 11 lbs.

The manufacturer reserves the right to alter these specifications without further notice.