Sugden Masterclass IA-4 User manual

SUGDEN
Masterclass IA-4 Integrated Amplifier
Instruction Manual
Masterclass IA-4 Integrated Amplifier
Designed and manufactured by
J E Sugden & Co LTD
Valley Works
Station Lane
HECKMONDWIKE
West Yorkshire
WF16 0NF
ENGLAND
www.sugdenaudio.com

UNPACKING
Your amplifier should reach you in a substantial protective carton. On unpacking, please
examine the unit for signs of prior use or damage. Check that all the front panel controls
function mechanically. The following items should also be in the carton:-
(a) AC power lead with pre-molded IEC straight connector and plug.
(b) Owners' registration card, which should be completed, and the bottom section removed
and returned to us.
INSTALLATION - IMPORTANT
There are three points that must be considered carefully when installing your amplifier.
1) Adequate ventilation.
2) Proximity to low level gain stages.
3) Proximity to heat source and direct sunlight
Because the Masterclass is a pure class A design, a large amount of heat will be generated
from the amplifier heatsink. It is VERY IMPORTANT that the amplifier must not be confined
in a space that will produce a build up or re-circulation of heated air. We recommend a
clearance of approx. 10cm (four inches) either side and above the unit. This will allow a free
circulation of air when situated in an open back cabinet.
CONNECTING TO A MAINS SUPPLY
Before connecting your amplifier to a mains supply ensure that the mains voltage rating on
the inspection ticket and packing carton is the same as your countries supply. Connection to
the mains is via the A.C. cable supplied with your amplifier and connects to the mains input
socket at the back of the amplifier.
SIGNAL CONNECTIONS
Always ensure that your amplifier is switched off before any connections are made to
associated equipment.
Loudspeakers
The loudspeaker connections are made via the four gold plated WBT binding posts at the rear
of the amplifier these are marked R(right) and L(left) for identical connection to your
loudspeakers. Both left and right speakers have a positive (+) and negative (-) connection
which are also for identical connection to your loudspeakers. We recommend that
loudspeakers of 4-16 Ohms impedance should be used with your amplifier.
Input Signals
There are three line level inputs, tape input, phono input and a balanced input.
Phono Input
This caters for moving magnet cartridges.
Balanced Input
The XLR sockets are for connection to a source with a balanced output such as the
Masterclass CD player. The pin configuration is the professional standard:
Ground Pin One
Positive (hot) Pin Two
Negative (cold) Pin Three
Outputs (low level)
There are two pairs of signal outputs, one is fixed, and the other is variable working from
amplifiers main volume control.
The fixed output can be connected to a tape recorder and is labeled Tape Output. The output
should be high enough to work with most analogue tape inputs and the analogue interface of
most digital recorders.
The variable output is called Pre-out and is designed for operating another power amplifier. It
can also be used to feed an active subwoofer or surround sound processor in a home theatre
system.

FRONT PANEL CONTROLS
Input selection
The rotary selector switch located on the right of the front panel selects the relevant input
signal i.e., Phono, Tape and are associated with the signal input sockets on the rear panel.
Volume control
The volume control adjusts the power delivered to the loudspeakers and hence controls
listening level. Zero volume is at anti-clockwise position or 'six 'o' clock'. The volume control
can be operated by a Sugden RC5 System remote control.
Tape monitor control
Use this control to allow true post recording monitoring on a three-headed tape machine or
recorder with monitoring facilities. What is heard is taken directly from the tape immediately
after recording. This allows A: B comparisons to achieve the desired recording.
Record on/off control
Although the tape circuit is relay switched, the purist can switch off the tape output signal to
avoid any possible signal degradation
Additional information
EARTHING
One of the most common problems with high performance audio equipment is an audible hum
through loudspeakers. Your amplifier has been tested for noise at the factory and you should
not be able to detect any obtrusive noise when the amplifier is connected to a pair of
loudspeakers. If you can hear an unreasonable level of noise that detracts from the music it
is probably caused by a hum loop associated to an ancillary piece of equipment. The most
common cause of this is ancillary equipment connected to the earth mains.
Should you remove the earth connections in ancillary equipment mains plugs remember:
LEAVE THE EQUIPMENT PERMANENTLY CONNECTED TO THE AMPLIFIER INPUTS. IF
THE EQUIPMENT IS TO BE REMOVED FOR ANOTHER USE IT MUST BE UNPLUGGED
FROM MAINS POWER BEFORE REMOVING FROM THE PHONO SOCKET INPUTS.
NEVER DISCONNECT THE MAINS EARTH FROM YOUR AMPLIFIER.
The amplifier should be switched off when not in use. Warm up time is about 15mins.
FUSES
Should a fuse blow this is usually an indication that a fault exists. It is important that the
cause of the fault is determined and rectified before replacing a fuse. If in doubt, consult your
local dealer or our distributor for assistance.
NEVER by-pass any fuse in your amplifier. NEVER replace a fuse with one of a different
specification or valve.
HT FUSES
There are two fast blow 2.5AMP fuses located on each of the power board modules. These
protect the amplifier from a short circuit on the loudspeaker outputs or over load.
MAINS FUSE
The mains Fuse is located at the rear of the amplifier and is externally accessible. It is
combined in the mains input socket together with a spare fuse of the correct value.

SUGDEN MASTERCLASS IA-4 Specification @ 230Volts setup.
Facilities
Inputs Three line level, one tape, one phono (mm), one
Balanced
Outputs One pair pre-out, one tape out, two pair WBT type
multi way locking binding posts
Phono Input Sensitivity 2mV MM
Input Sensitivity 125mV for maximum output
Power Output 33 Watts into 8 ohms
Frequency Response 14Hz to 200kHz +/- 1dB
Bandwidth 6Hz-300kHz +/- 3dB points
Signal to Noise Ratio >100dB
Input Impedance 50K
Nett Weight 19kg
Dimensions 165 x 430 x 440mm (hwd)
The manufacturer reserves the right to alter specification without notice
.
Designed & Manufactured By
J. E. Sugden & Company Limited
Valley Works Station Lane Heckmondwike
West Yorkshire WF16 0NF
ENGLAND
www.sugdenaudio.com