DALLEE ELECTRONICS 671 User manual

11 Watt Amplifier
with true Treble & Bass controls!
Item #671
This amplifier was designed to be used with
all Dallee Electronics Inc. sound systems
and may also be adapted to other systems.
The amplifier includes both Treble and Bass controls and is
designed for use with 8 ohm, or higher, speakers. Do not
use 4 ohm speakers or multiple speaker configurations
equivalent to less than 8 ohms! The amplifier is small
enough to fit most 'S' gauge and larger type trains.
Excess heat can be generated when volume is set to high
levels or with Bass set to boost so when installing this
amplifier be sure to allow for adequate ventillation and do
not place the board too close to plastic body shells. Note:
cutting Treble rather than boosting Bass results in a bass
effect with less heat being generated.
Standard round speakers are usually rated for 1/2 watt or
less and are not appropriate for use with this amplifier. Use
of heavier wattage speakers, as availble from Dallee
Electronics, are recomended.
The maximum DC input is 25 volts. Typical operation is in
the 12 to 24 volt range. If insufficient voltage is present, the
amplifier will not turn on, i.e. pass any sound to the speaker.
Output power is limited to that of the supply power.
Inadequate supply power will hamper the amplifiers ability to
perform the audio output power desired. This unit will also
shut down (turn off) if it gets too hot. Adequate cooling must
be provided if this is a problem.
Input power connections are to be connected to the DC
source specified observing proper polarity. The input power
is not protected from reverse power to allow for the highest
audio output with a low DC input voltage. None of the
speaker connections, nor any other connection or part of the
board, should come in contact with any other connection or
metal body part. Improper connections will destroy the unit
and void all warranty.
Refer to the sound system that you are using and follow the
installation instructions.
General installation:
246 W. Main St.
Leola, PA 17540
[phone]
www.dallee.com
INPUT CONNECTIONS
Terminal # connection
1...................'+' DC
2...................'–' DC
3...................audio
1
2
3
Speaker connection
(8 ohms or higher)
Avoid contact to other
metals and allow
adequate air passage for
proper cooling.
2x56 mounting
screw location
(3 provided).
Remote volume control with Auxillary Amplifier
With single sound systems, connect the gray wire from the speaker output to input "I". Connect
the rest as shown.
If using two sound systems, connect the junction of the two sound systems 1k resistors
(shown on the backside) to the "+" side of the capacitor (labeled I ), then merely add the potentiometer as shown.
1 2 3
Remote
volume
control
External Volume control
package (item #601)
I
Gray
audio input from
sound system
clockwise
—›
1
32
1 mfd capacitor
Observe polarity!
+
viewed from front
Amplifier DC input power
Red -> +DC
Black -> ground
This needs to be the same
as the sound system power.
1
2
3
auxillary AUDIO AMPLIFIER,
Item #671 or #672
1
2
3
Power and audio connections shown.All other items get
connected as per previous instructions / installation chosen.
Remeber, the audio amplifier's require at least 12 volts to operate
with a 24 volt maximum limit.
no connection!

Capacitors shown are not necessary when using filtered DC
track power. If unfiltered DC, only one may be necessary. Static
in the amplifier will be the clue for more capacitance. It never
hurts to have the capacitors in place for more filtering of the DC
track power in the locomotive.
Utilizing Fixed DC or AC track power to provide the
Power Amplifier and DC Sound System power in
lieu of batteries in an on board application with
receiver operating from track power.
"•" denotes connection, join wires together & insulate.
Otherwise wires are just passing over and do not connect.
Replaces Battery Power Input
as shown in wiring diagrams for
DC sound systems.
Connect to J2 of Sound System
with RED to +DC and GRAY to
– DC. Also connect to Amplifier
RED to +DC and BLACK to
–DC.
Be sure to wire the "+" and "–"
correctly!
Track Pickup
Left Rail Pickup
Right Rail Pickup
Bridge Rectifier
4A 100piv
(Item #371)
+ DC
– DC
2 x 4,700 mfd @ 25 vdc
(item 205)
Observe polarity!
+
–+
–
Using two or more sound sytems with 1 amplifier
By placing a 1k resistor in series with each sound
systems output and then tying them together a mono
channel can be obtained for utilizing a single amplifier.
This drawing is shown to the right.
When using DCC or other AC type input, DC power for
the amplifier can be obtained from one of the sound
systems as shown. The other sound system can be
powered from the DCC or AC source as well as the same
DC source used to power the sound system. The top
sound system has to be powered in oreder for this
common power method to work. You may also provide
for more DC filtering, if needed, by placing a large
electrolytic across the DC power.
1k
1k
Amplifier
power input.
Only 1 output from each sound
system is needed. If desired, you
can still power another speaker
from each sound system!
Using with DCC or other fixed voltage track power
system and Dallee Electronics DC Sound System.
When using a single Dallee Sound system, wire the DCC track
power as shown (pins 5 & 6). Wire the DC output terminals (pins
3 & 4) to the amplifier. Do NOT get the polarity reversed to the
amplifier! That would destroy it and is not covered under any
warranty!
All functions, motor inputs, audio input get wired as before,
shown in the sound systems instructions.
When using a dual system, only wire one of the sound system to
the track power (J1) input. Wire the other sound system to
operate from the DC (J2) power as shown for the amplifier
above.
If 60 Hz track power is present, extra filtering of the DC power
(from J2) is required. Use a 6800mfd or higher value capacitor
with at least a 25 volt rating.
POWER
AMPLIFIER
DCC or other fixed
voltage Track
Power
Gray
Red
Gray
Red
Black
Gray wire from sound
unit. Tape end of red
wire to prevent shorting.
Version 3 DC
Sound System
1
2
3
Power and audio connections shown. All other items get
connected as per previous instructions / installation chosen. Remeber, the audio amplifier's require at least
12 volts to operate with a 24 volt maximum limit.
Auxillary Amplifier connections with two speakers.
Speaker 1
Speaker 2