Redgum RGM175 User manual

REDGUM
Operating Instructions
for
REDGUM Amplifiers
Models
RGM175 & RGM300

2
Operating Instructions for your
REDGUM Amplifier
The power switch is on the left of the front panel and is operated by the key provided.
The power is off when the key is vertical. To turn on the power, rotate the key clockwise
1/4 turn. The key can be removed in the “on” position, but for safety reasons, it is
suggested that the key be left in when the power is on. If preferred, the key switch can
be left in the “on” position and the power controlled from the wall outlet or the rocker
switch on the rear. The power into the two Monoblocks can be controlled with the key
switch using the supplied 3.5mm phone cables. Remote power-up can be arranged
using the Control sockets on the rear (see page headed Remote Power-up Instructions
for details).
The Input Selector is on the right-hand side of the front panel and rotates from DVD
through to AV2. All of the inputs have the same sensitivity, so any ‘line level’ input can
be connected to any input position.
If your REDGUM amplifier has Dual-Mono Volume Controls, this functions as a separate
level control for each channel. These controls are normally moved together but can be
moved separately to achieve balance. Should you have a REDGUM amplifier with a
Single Volume Control, the center control acts as a quasi Balance control.
These volume controls should approximate live 'concert hall' levels at the 12 O’clock
position. In this position “clipping” of the signal is rare and no damage to speakers or
amplifier should result, however pushing to 2 O’clock and beyond can result in ‘clipping’
distortion which is the major cause of speaker damage, so use with care!
REDGUM amplifiers use new generation Metal Oxide-doped Silicon, Field Effect
Transistors (MOSFET’s), which can operate into impedances below 1 ohm without
damage as they are not prone to secondary breakdown like normal transistors. But
long-term, very high listening levels with speaker impedances below 4 ohms may cause
the internal heatsinks to rise past 80 degrees Centigrade. This will result in the
protective thermal ‘cut-out’ operating and shutting off power to the amplifier. The power
will automatically restore once the amplifier cools down again. If this occurs regularly,
consult your dealer. Where your speakers are low impedance, and/or low sensitivity,
moving to a higher power REDGUM amplifier should be considered.

3
Set up Instructions
RISQUE DE CHOC ELECTRIQUE
RISK OF ELECTRIC SHOCK
NE PAS OUVRIR
DO NOT OPEN
N1450
Australia
Made in
OutIn
AC ~220-240V 50/60Hz
300W (Max.)
Remote
Switching
+-
Speaker
Input
L
R
Out DVD1 DVD2 VCR CD AV1 Preamp Out
Record
REDGUM RGM175 Passive Pre-Amplifier
Made in Australia Ne Pas Ouvrir
Do Not Open
Risk of Electric Shock
Risque de Choc Electrique Remote
Switching Out
In
RISQUE DE CHOC ELECTRIQUE
RISK OF ELECTRIC SHOCK
NE PAS OUVRIR
DO NOT OPEN
N1450
Australia
Made in OutIn
AC ~220-240V 50/60Hz
300W (Max.)
Remote
Switching
+-
Speaker
Input
WARNING –Do not put the power cords in first!!!!
Set up the REDGUM Amplifier on a flat surface by first placing the right hand channel,
(denoted by the red ring around the RCA input socket) then place the left hand channel
next(black ring) and on top the preamp. This stacking method will allow the best visual
match of the Red Gum front panels.
Next use the supplied RCA cables to connect the preamp to the power amp as shown
on the left hand side of the above drawing. Left (upper on preamp) to Left monoblock) –
Right to right.
Next connect the 3.5mm phone ‘control’ cable (supplied) from the ‘Control Out’ of the
preamp to the ‘Control in’ on the left channel power amp. (as shown on the right hand
side of the drawing above) Now connect the second ‘control’ cable from the ‘Control
out’ of the left hand channel to the ‘Control In’ of the right hand channel.
Check that the power control switch on the preamp is in the ‘off’ position. Also check
that the ‘rocker’ switches on the back of the power amplifiers are both ‘Off”
Now connect 2 x IEC power cords to the outlets on both power amplifiers, but leave
them out of the wall sockets. You are now ready to connect your speakers and source
components.

4
Input Connections
L
R
Out DVD1 DVD2 VCR CD AV1 Preamp Out
Record
REDGUM RGM175 Passive Pre-Amplifier
Made in Australia Ne Pas Ouvrir
Do Not Open
Risk of Electric Shock
Risque de Choc Electrique Remote
Switching Out
In
WARNING:-Make sure that your REDGUM Amplifier is disconnected from mains power
before making any input connections to your other equipment. Failure to do so may
result in an electric shock and/or damage to the amplifier or other product.
Connect your DVD Player to your REDGUM amplifier using high quality RCA
interconnects between your player and the sockets labeled DVD1 (Left Output on DVD
to Left Input on Amplifier, etc).
Connect a Video Cassette Recorder to the sockets labeled VCR (Left Output on VCR to
Left Input on Amplifier, etc.).
Connect your CD Player to your REDGUM amplifier using high quality RCA interconnects
between your player and the sockets labeled CD.
Connect an AmFm tuner to sockets labeled AmFm (Left Output on Tuner to Left Input
on Amplifier, etc.).
Connect a Cassette deck or DAT tape to sockets labeled Tape 1 (Left Output on CD to
Left Input on Amplifier, etc.).
Connect any other audio product to any unused inputs.
NOTE:
Connect any choice of ‘Line Level’ inputs to your REDGUM input sockets as all inputs
are direct connected to the power amplifier stages when selected on the front panel.
Any selected input is also direct connected to the Tape Out sockets for ‘straight
through’ or ‘unprocessed’ recording. Should you wish to connect a Turntable to your
REDGUM Amplifier, you may need a separate Phono pre-amplifier. The REDGUM range
does include a stand-alone Phonostage. If in doubt, consult your dealer.

5
Speaker Connections
+-
Speaker
Input
WARNING:-Make sure that your REDGUM Amplifier is disconnected from mains power
before making any connection to speaker terminals. Failure to do so may result in an
electric shock and/or damage to the amplifier.
Using heavy speaker cable (the heavier, the better and with a 2mm minimum), hook up
the speaker on the right side of your listening area by connecting the positive terminal
of the right speaker to the positive (red) terminal on your REDGUM amplifier (labeled
+ve Right channel). Connect the other terminal on your right speaker to the amplifier
(labeled -ve Right channel).
Hook up your Left Speaker using a similar procedure.
Before turning on the power, check that wiring terminations look neat and that no loose
strands of wire are touching any another terminals. Failure to make neat connections
may result in poor sound, or amplifier damage.
Note:
The second set of speaker terminals on some REDGUM amplifiers are for Bi-Wiring.
Consult your dealer (with information on your loudspeakers) for details on whether Bi-
Wiring is possible, or suggested with your system.

6
First Power-On!
Now that you have your REDGUM Monoblock system all ready to run you should hook
both the IEC power cords to the mains supply. Both power amps should show a red
glow from the rocker switches to show that power is available, but not currently ‘on’.
Switch both rockers to reset position. The red ‘tripped’ lights should both go off.
Your system is now ready to power up via the key switch on the front of the preamp.
The key switch will start up the left channel power amplifier, then the left channel
power amplifier will control the power to the right hand channel. This does happen very
quickly, and you may not notice the short time delay.
You will only need to read this page further if you plan to use our ‘daisy-chain’ sequential
power-on facility.
Remote power control:
Your REDGUM Amplifier has two Control sockets on the rear.
The Control In socket can be used to power up your amplifier from another
place/product.
The operation is as follows:
1/ with no plug/lead in the Control In socket:
the amplifier will power up when the key switch is turned to the right.
2/ with a lead plugged into this socket:
when the circuit is completed at the other end of the lead, the amplifier will
power up. When the circuit is ‘open’, the amplifier will shut down. The key switch
will over-ride this system only to shut down the amplifier.
The Control Out socket circuit will be completed approximately 1 second after the
amplifier is activated, so ‘daisy-chaining’ of several amplifiers is possible with each unit
powering up the next one and with only a short time delay. This facility is to allow for
the powering up of large numbers of single and/or multi-channel amplifiers for use in
home theatre or commercial applications.

7
Troubleshooting
Lost keys can be replaced. Information is kept on file at the factory about every REDGUM
amplifier manufactured. By quoting the Serial Number, another key can be provided. (The S.N. is
found underneath the amplifier, on the carton, or on the Final Test report.)
Just fax a request for a new key and include your FINAL TEST REPORT (with details of any
change of address) to: REDGUM Australia -Fax [phone].
A replacement key will be sent by Air Mail the same day.
*****
When turning the power “on”, a slight “pop” may be heard from the speakers. This is normal and
will not damage your loudspeakers. When turning the power “off”, the amplifier will continue to
operate until the reservoir capacitors are exhausted. During this time, odd sounds may be heard
-they also are normal and will not harm your speakers.
*****
DO NOT REMOVE THE COVER of your REDGUM amplifier
-there is the RISK of a FATAL ELECTRIC SHOCK.
-
There are no replaceable fuses in this REDGUM Amplifier. The only overload devices are thermal.
Internally, there are thermal cut-offs that will shut down the amplifier if the heatsinks reach 80
degrees Centigrade. This would usually only happen if the speaker leads remain ‘shorted’ for
some time. If the Amplifier suffers an internal malfunction, the rocker switch/circuit breaker on
the rear will ‘trip’ and a red light will be seen inside it. If reset, it will refuse to stay “on”. In the
unlikely circumstance that this occurs, the amplifier will need professional service. If in any doubt
whatsoever -consult your dealer. *****
Before returning your amplifier for repair, REDGUM Audio recommends the following test.
First, replace all interconnect leads. There is a very high fault rate with expensive interconnect
leads.
On several ocaisions amplifiers have been returned as faulty and later it has turned out that the
horrendously expensive interconnect leads were faulty when unpacked!!
Disconnect all connectors from inputs, tape out and speaker terminals. Connect a pair of
speakers (with attached leads) from another system that you know is working. Also connect a
CD player (with its own leads) that is known to be working. By doing this, you can establish
whether the fault lies with the amplifier, or another part of your system.
Should the product be faulty, the owner is liable for the cost of freight to the nearest REDGUM
repair agent, or the factory. Should the product be found to be without fault, the owner may be
charged for the return freight also.
INTERMITTENT FAULTS: Everyone’s worst nighmare!
Intermittent faults can be due to many causes both internal and external to the amplifier. For
the best fault resolution in these cases, you will need to be a good sleuth! Gather as much
information about the timing, temperatures, source material and anything that you can –too
much information is not possible!
If you are able to, make direct contact with REDGUM Audio Pty Ltd via email :
[email protected] and we will guide you through. There is nothing more frustrating for
you, the customer, to return a product under warranty, and have it returned to you with the
same symptoms!! We aim to fix your problem, whether it is in the amplifier, or the environment
that the amplifier is being used! Please bear with us.

8
Warranty Registration
Complete for Warranty Registration :
Name __________________________________________________
Address ________________________________________________
City _________________________________ Zip code__________
Country _____________________ Date of purchase__________
Place of purchase ______________________________________
Model No.______________________________________________
Serial No. (if any) _______________________________________
Email (for Product Updates)______________________________
Fax this page to the REDGUM Audio factory at
[phone]
or
Email all details (incl. S.N.) to [email protected]