Mistral DT-307B User manual

DT-307B
Vacuum Tube Amplifier
Instruction Manual

2
Thank you for purchasing this Mistral DT 307B Amplifier.
This instruction manual provides all of the information that you need to know
about your MISTRAL DT-307B. Please read it carefully before you start
using the unit.
The Mistral DT 307B is a high quality hybrid tube / transistor amplifier for
use in iPod and Hi Fi system applications. It has several input options to
enable users to connect a variety of digital and analogue music sources. It’s
compact dimensions, robust build and high quality finish make it a practical,
long lasting and durable iPod or Hi Fi system component.

Contents
3
Safety Instructions 4
System Profile 7
System Set Up 8
Vacuum Tube Amplifier Instruction 9
Troubleshooting 10
Specifications 11

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.
3. 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.
4. Do not place near direct heat sources such as radiators, stoves,

Safety Instructions
5
gas fires, naked flames or candles.
5. Ensure that the unit is placed on a clean, dry and flat surface
before operation.
6. Do not drop the unit, apply excessive force to the controls or
place heavy objects on top of the unit.
7. 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.
8. 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.
9. 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.
10. 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.
11. Always make sure power cables are placed safely and are not
obstructing a walkway.
12. This product can get hot. Do not touch the tubes and keep away
from babies, children and pets.
13. 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.
14. 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 tuned “OFF”.
15. 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
16. Always turn OFF the power switches when connecting or
disconnecting from mains power.
17. 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.
18. Refer to the owner's manual of each component that is
connected to this unit.

System Profile
7

System Set-Up
8

Vacuum Tube Amplifier Instructions
9
Bluetooth Connection
Select BT on the right hand input selector switch.
Select Bluetooth on your audio source e.g. Smartphone, Laptop etc.
After a short time BLUE SPEAKER will appear on your audio source
screen. Select “Pair”.
DT307B will now be ready to play your music wirelessly within a
range of approximately 30ft.

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
No power when unit is turned on.
Switch on the electric current at the
socket
Check that the plug has been
correctly inserted into the socket.
The internal fuse has blown and
must be replaced by a qualified
service technician.
The power cord has been
damaged and must be replaced.
Input selection is not correct.
Ensure input selection is set to the
correct source.
No sound.
Input source volume is low.
Increase the volume level on the
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
that they are connected correctly.
Sound is distorted
Volume level on speaker system
is set too high. Decrease
Volume.
Sound source is distorted. WAV
and MID files are sometimes of
poor quality. Therefore distortion
and noise are easily noticed on
high quality systems. Try a
different audio source (e.g. CD
Player)

Technical Data
11
Kit Contents
Vacuum Tube Amplifier
3.5 mm Stereo Cable
Specifications
Power Output
25W x 2
Frequency Response
20Hz –20kHz
Harmonic Distortion
<=0.1%
Signal-to-noise ratio
>=85dB
Input Impedance
470kOhms
Power Supply
AC100V –120V 50/60Hz
AC220V - 240V 50/60 Hz
We reserve the right to change the technical data and the design of the
product without notice as a result of further development.