3
Unpacking.
Remove the 4 top blue foam corners. Open the inner box, remove the 2 top blue foam parts
Lift the amplifier up and place it on its feet. Be careful not to damage the gold plated connectors on the
back panel. Keep the box and the blue foam, it is specially made to protect the amplifier well, and you
may need it some day, when you move or you want to upgrade the amplifier.
Connecting the input cables.
The main inputs are the two 3-pin XLR sockets. They are electronically balanced, and they will therefore
reduce hum pickup in the input cables. So the best choice of cable is a balanced XLR cable, coming
from a balanced output on your preamplifier.
In case you have a preamplifier with only RCA outputs, you can use the RCA inputs. Move the switch
towards the RCA. Use only one input, RCA or XLR, not both.
We recommend purchasing our balanced cable wired with a male XLR in one end, and an RCA plug in
the other end. This will give you partly balanced operation in the cable, with an unbalanced source.
You release the XLR connector by pressing on the release button next to the XLR socket, and pulling the
XLR plug out at the same time. Do not pull on the cable, only on the plug.
The XLR connector: always connect Pin 1 (the ground) first and disconnect it last. This way, XLR
connectors can be plugged and unplugged while the amplifier is switched on.
However, some DC from the preamplifier may still cause loud clicks, so it is recommended to wait 10
seconds and then switch the power amplifier on as the last precaution. If you use a tube preamplifier,
please wait several minutes the first time you use it. Also do switch off the power amplifier first, before
switching off your preamplifier or any source.
DO NOT CONNECT LOUDSPEAKER WIRES OR OTHER
HIGH VOLTAGE CABLE TO THE INPUTS.
Warming up
The GamuT power amplifier will play sound a few seconds after you turn it on. However, please allow
minimum 30 minutes before you start serious listening, as the sound quality will slowly improve, because
all the parts need to reach their optimum operating temperature.
You may also note a slight improvement in the first months of use. This is caused by the capacitors,
which do improve with use.
A CD player in repeat mode can speed up the process while you are not at home. Do not play too loud.
After this break-in period is over, simply switch the GamuT on when you get home, and it will be ready to
perform at its best after dinner.
Sensitivity (Gain)
Inside the cabinet, at the top edge of the circuit boards, is a dual piano switch marked -6 dB and -12 dB.
Normally gain is factory set at -6dB or 29dB total voltage gain.
Your dealer can set them for you, so that you get the best match for your preamplifier. To match a
passive "preamplifier" like our GamuT control unit, the gain has to be high, so set both switches to "off".
Some preamplifiers also need maximum gain, others have a lot of gain in their output section and there-
fore should be used with the -6 dB or -12 dB switch moved away from "off". If both switches are moved
away from "off", then the gain is reduced by 14 dB. We recommend that with 4 Volt sources like our
GamuT CD player. Noise levels will be lower. We use switches, because they can be set precisely
identical and will preserve the stereo balance.
The maximum voltage gain of GamuT M250 MkIII is 35dB, and the GamuT C100, D100, D200 and M200
also have 35 dB maximum gain, so they will all work together in a bi-amped system.
