Mistral MM-4 User manual

MM-4
Vacuum Tube Amplifier
Instruction Manual

2
Thank you for purchasing this Mistral MM-4 Amplifier
This instruction manual provides all of the information that you need to know
about your Mistral MM-4 Vacuum Tube Amplifier. Please read it carefully
before you start using the unit.
The Mistral MM-4 is a high quality Vacuum Tube Amplifier for use in Hi Fi
system applications. It can be used as a ‘straight through’ integrated
amplifier for use with a single source, or it can be used as a power amplifier
with a separate pre amplifier. It’s compact dimensions, robust build and high
quality finish make it a practical, long lasting and durable Hi Fi system
component

Contents
3
Safety Instructions 4
System Setup 7
System Operation 9
Troubleshooting 10
Maintenance 11
Technical Specification 12

Safety Instructions
4
IMPORTANT
Please read this manual before operating your Mistral amplifier. Observe
the Safety Instructions to avoid electrical shocks or equipment failure due to
improper installation. Please retain these instructions in a safe place for
future reference.
A triangle with a lightning symbol indicates
“dangerous voltage” which may be high enough to
entail risk of electric shock.
A triangle with an exclamation mark indicates
important instructions for use and maintenance in
the accompanying manual.
To prevent risk of electric shock, do not remove
cover (or back). Refer servicing to qualified service
personnel.
1. Observe all safety warnings given in the manual.
2. If the unit produces smoke, a strange smell, or strange sounds
upon turning the product “ON”, the unit may have been damaged
in shipment. If this happens, immediately switch the power “OFF”
and unplug the power cord.
a. This unit should NOT be situated in close proximity to
water. E.g. Near baths, sinks, washing machines,
swimming pools, saunas etc. Avoid exposure to direct
sunlight or to extreme temperature, humidity, or changes
in temperature.
3. Do not place near direct heat sources such as radiators, stoves,

Safety Instructions
5
gas fires, naked flames or candles.
4. Ensure that the unit is placed on a clean, dry and flat surface
before operation.
5. Do not drop the unit, apply excessive force to the controls or
place heavy objects on top of the unit.
6. Do not allow excessive levels of dust to gather on the amplifier.
To clean, unplug the cooled unit and use a soft dry cloth. If
necessary, use a damp cloth without any solvents.
7. Ensure that the area in which the unit is situated has adequate
ventilation. Do not place the amplifier in a position where its
ventilation may become obstructed.
8. Avoid placement on beds, sofas, rugs, enclosed bookcases /
cabinets and any other area which may cause interference to the
ventilation of the product thus causing it to overheat.
9. Ensure that the unit is connected to the correct power supply as
indicated on the unit. Unplug the amplifier when not in use for a
long period.
10. Always make sure power cables are placed safely and are not
obstructing a walkway.
11. This product can get hot. Do not touch the tubes and keep away
from babies, children and pets.
12. To avoid risk of electric shock, do not attempt to remove the
cover or the back of unit. There are no user serviceable parts
inside. Refer servicing of internal parts to qualified service
personnel. Any unauthorised changes or modifications to this
equipment would render the manufacturer's warranty null and
void.
13. WARNING: Tube electronics use high voltages that can cause
injury or death. Dangerous voltages may be stored in capacitors
many hours after the unit has been turned “OFF”.
14. Check that your local mains supply voltage agrees with the
setting indicated on the back panel of the amplifier. Always use a
quality power surge protector.

Safety Instructions
6
15. Always turn OFF the power switches when connecting or
disconnecting from mains power.
16. It is recommended that you disconnect the power supply from the
mains when the unit is in a protracted period of non-use
(holidays, etc) and during initial setup.
17. Refer to the owner's manual of each component that is
connected to this unit.

System Set-Up
7
System Connection
The Mistral MM-4 is a hybrid tube / transistor amplifier which can be used as a
power amplifier or as a ‘straight through’ integrated amplifier. The source or
pre amplifier inputs are at the rear. Please connect the system according to
the diagram below:
1. Power On/Off Switch: This turns the amplifier on or off. Before
switching on the power, be sure to set the volume control to the
lowest setting in order to avoid damage to the speakers..After turning
the amplifier on, wait approximately 10 seconds for the vacuum tubes
to warm up.
2. Volume Control: This controls the volume level
3. RCA Input Jack: Before connecting source components or a pre
amplifier to or from this unit, ensure that the unit is switched OFF.
Use only RCA connecters to connect sources such as CD players,
DACs to the unit input jack. If the unit is to be used as a power
amplifier, a pre amplifier can also be connected via the input jack.

System Set-Up
8
4. Speaker Connection: Before connecting your speakers to or from
this unit, ensure that the unit is switched OFF. Connect your left and
right speakers using the left/right binding posts. Polarity is important.
Connect “+” to red, and “-“ to black binding post. Connect your
speakers to the binding post with correct impedance to achieve best
results. If you are not sure about the impedance of your speaker,
please consult your speaker supplier.
5. Mains Connector: Plug the IEC connector to the amplifier and plug
the other end into an AC (mains) outlet.
6. Vacuum Tube Holder (M800A): Each holder is used to hold one
vacuum tube. When the amplifier is turned on, the filament of the
tube will light up.

System Operation
9
With the system correctly connected, you are ready to enjoy your music with
this high quality tube amplifier.
On/Off
The ON/OFF switch is on the back panel of the amplifier. When switched On,
the filaments of the vacuum tubes will light up. Wait a few minutes for the
vacuum tubes to fully warm up.
Volume
There is a volume control on the front panel. By turning the knob to the
right/left you can increase/decrease the volume level. Always turn the unit On
with the volume level set to minimum.

Troubleshooting
10
If the unit fails to operate normally, check the following points to determine
whether the fault can be corrected. If it cannot be corrected, or if the fault is
not listed in the Problem column, disconnect the power cord and contact your
authorised dealer or service centre for help.
Problem
Cause/Remedy
The unit fails to turn on when the
POWER switch is turned on.
Power cord may not be plugged in
or is not properly inserted. Firmly
seat the power cord.
No sound.
Input source volume is too low.
Increase the volume level on the
audio source device.
No volume or low volume. Turn
the volume control to increase the
volume level.
Speakers are not properly
connected to the unit. Check
cables are connected correctly.
No sound is heard from the left and/or
right speakers
Speakers may not be properly
connected to the unit
Signal input may not be properly
connected to the unit
Acoustics are not as expected –
unnatural sound and insufficient low
range tonal quality
The positive (+) and negative (-)
polarities of this unit and the
speaker systems are not matched.
Reconnect the speaker system to
this unit so that the polarities are
aligned.

Maintenance
11
Use only a soft, dry cloth to clean the outside of the MM-4.
Use dry cloth to hold the vacuum tube when plugging and unplugging
the tubes.
Avoid touching the tubes when the MM-4 is operating. This will leave
finger prints on the tubes and potentially decrease its life. They may
also get hot in operation.
Do not use any solvents, chemicals or cleaning solutions containing
alcohol, ammonia or abrasives.
Ventilation should not be impeded by covering the ventilation
openings.
The mains plug should be easily accessible in order to disconnect the
device if required.
Note: Always unplug your MM-4 from the AC mains socket before
performing any maintenance.

Technical Specification
12
Power Output
40W x 2
Frequency Response
20Hz –40kHz
Signal-to-noise ratio
>=90dB
Dimensions
W260 x D290 x H110
We reserve the right to change the technical data and the design of the
product without notice as a result of further development.