HTD DA-2125 User manual

DA-2125
Multi-Source Stereo Amplifier
Owner’s Manual
Home Theater Direct, Inc.
www.htd.com
Expert Support:
866-HTD-AUDIO (483-2834)
[email protected]
© Copyright Home Theater Direct, Inc.03.27.15

Safety Instructions for the DA-2125
CAUTION
RISK OF ELECTRIC SHOCK
DO NOT OPEN
!
!
The lightning ash with arrowhead symbol, within an equilateral triangle, is intend-
ed to alert the user to the presence to un-insulated dangerous voltage within the product’s enclosure
that may be of sufcient magnitude to constitute a risk of electrical shock to persons.
The exclamation point within an equilateral triangle is intended to alert the user to the
presence of important operating and maintenance (servicing) instructions in the literature accompany-
ing this appliance.
Read Instructions
All safety and operating instructions should be read before the
appliance is operated.
Retain Instructions
The safety and operating instructions should be adhered to.
Heed Warnings
All warnings on the appliance and in the operating instructions
should be adhered to.
Follow Instructions
All operating and use instructions should be followed.
Water and Moisture
The appliance should not be used near water. For example,
near a bathtub, washbowl, kitchen sink, laundry tub, in a wet
basement, or near a swimming pool, etc.
Ventilation
The appliance should be situated so that its location or position
does not interfere with its proper ventilation. For example, the
appliance should not be situated on a bed, sofa, rug, or similar
surface that may block the ventilation openings: or placed in
a built-in situation, such as a bookcase or cabinet that may
impede the ow of air through the ventilation openings.
Heat
The appliance should be situated away from heat sources such
as radiators, heat registers, stoves, or other appliances (includ-
ing ampliers) that produce heat.
Power Sources
The appliance should be connected to a power supply only of
the type described in the operating instructions or as marked on
the appliance.
Grounding or Polarization
Precautions should be taken so that the grounding or polariza-
tion means of an appliance is not defeated.
Power Cord Protection
Power supply cords should be routed so that they are not likely
to be walked on or pinched by items placed on or against them,
paying particular attention to cords at plugs, convenience re-
ceptacles, and the point where they exit from the appliance.
Cleaning
The appliance should be cleaned only as recommended by the
manufacturer.
Power Lines
An outdoor antenna should be located away from power lines.
Non-Use Periods
The power cord of the appliance should be unplugged from the
outlet when left unused for long periods of time.
Object and Liquid Entry
Care should be taken so that objects do not fall and liquids are
not spilled into the enclosure through openings.
Damage Requiring Service
The appliance should be serviced by qualied personnel when:
a) the power supply cord or the plug has been damaged: b)
objects have fallen, or liquid spilled into the appliance: c) the
appliance has been exposed to rain: d) the appliance does
not appear to operate normally or exhibits a marked change
in performance or e) the appliance has been dropped, or the
enclosure damaged.
Servicing
The user should not attempt to service the appliance beyond
that described in the operating instructions. All other servicing
should be referred to qualied service personnel.
Product Servicing
If your system fails to operate properly, please contact HTD
directly for further assistance, at 1-866-483-2834.
Additional information, including detailed specications for each
model, can be found on our website, www.htd.com. Thanks
again for choosing Home Theater Direct!
If you have any questions, we can be reached at...
[email protected] or toll free 1-866-HTD-AUDIO (483-2834)
Warning - To reduce the risk of re or shock, do not expose this appliance to rain or moisture.
Caution - To reduce the risk of re or shock, do not remove the cover or back. No user serviceable parts inside.
Refer servicing to qualied service personnel.
Caution - To prevent electric shock, match wide blade of plug to wide slot, fully insert.

3
DA-2125 Multi-Source Stereo Amplifier
Owner’s Manual
Home Theater Direct, Inc.
www.htd.com
Expert Support:
Toll free: 866-HTD-AUDIO (483-2834)
[email protected]
Introduction
The DA-2125 Multi-Source Stereo Amplier is an ideal solution for affordably expanding great
sounding music throughout your home. Multi-source features are built around a high current, two-
channel (stereo) amplier that is built solid with a large toroidial transformer that produces a warm,
full-bodied sound guaranteed to impress even the most fastidious listener.
Select between 6 stereo input sources using either the touch-buttons on the front of the unit or the
credit card-sized remote control. Two pairs of binding posts on the back of the DA-2125 allow for
easy connection of two pairs of 8 ohm speakers. In fact, four pairs of speakers can easily be con-
nected as part of an impedance matching system using impedance matching stereo volume con-
trols.
An A/B speaker switch makes it easy to turn on or off groups of speakers (A, B, or A+B). Use the
Remote Control to adjust treble and bass to get just the sound you want. Save on your utility bill
by using the Auto On-Off switch to automatically have the DA-2125 turn on when the source se-
lected is active and off when no source signal is sensed for several minutes.
Thank you for giving Home Theater Direct the chance to win your business! We are condent
you will nd that HTD offers an outstanding combination of performance and value in everything
we make. To ensure you get the most out of your new amplier, please take a moment to read this
manual before you get started. Should you lose this manual, you can always download or print a
copy from www.htd.com.

4
Product Features
Power Selection Switch, Power Button, and Power Indicator Light
The Power Selection Switch is found on the back of the unit. It includes three settings that will af-
fect how the unit is turned on and off.
• REMOTE - allows the user to use the power button on the Remote Control to turn the unit
on and off as long as the Power Button (on the front of the unit) is pressed in. Note that in
this setting you cannot turn the unit ON unless you have the remote control. The unit can still
be turned OFF by pressing the Power Button to the OUT position.
• AUTO - the unit will turn ON when an input signal is sensed by the source that is selected
and will go into STAND-BY/OFF after several minutes of no signal. The Power Button should
be in the IN position. If the Power Button is in the OUT position, the unit will not turn on.
• ON - allows the user to manually turn the unit ON and OFF by pushing the power button IN
or OUT on the front panel.
The Power Indicator Light will be dim blue when the unit is in stand-by mode and bright blue when
the unit is active. The Power Indicator Light will not be lit when the Power Button is in the OUT
position.
Speaker Output Buttons and Speaker Terminals
The Speaker Output Buttons on the front of the unit allow the user to control which speakers, or
groups of speakers, are active. When the “A” button is pressed in so that the indicator light is il-
luminated, all of the speakers connected to the Speaker Terminals (located on the back of the unit)
marked “A” will be active. When the “B” button is pressed in so that the indicator light is illumi-
nated, all of the speakers connected to the Speaker Terminals marked “B” will be active. Note that
it is possible to have both A and B active at the same time but the impedance load on A must be a
minimum of 8 ohms and the impedance load on B must also be a minimum of 8 ohms. If you will
only be using A or B (but not both at the same time), the minimum impedance load is 4 ohms.
It is possible to connect multiple pairs of speakers to A and multiple pairs of speakers to B by using
impedance matching volume controls to correct the impedance load to a safe level. See Figure 4
in the Speaker Connection section.
Source Selection Buttons and Stereo Inputs
The DA-2125 allows for easy selection of up to 5 analog stereo sources and 1 optical (digital)
source. The analog stereo sources are connected using standard RCA-type patch cables (sold
separately) to the Stereo Inputs located on the back of the unit. The optical source will be con-
nected via a standard TOSLINK optical cable (not included). To select a source, simply touch
one of the six Source Selection Buttons located on the front of the unit or press one of the Source
Selection Buttons found on the Remote Control. The indicator light directly above the source that
is selected will be illuminated. Note: that only one source can be selected at a time.
Motorized Volume Knob
The volume knob located on the front of the unit equally controls the output volume level of the
speakers connected to the Left and Right Speaker Terminals on the back of the unit. The Volume
Knob can be rotated manually or by using the Remote Control. When using the Remote Control,
never impede the rotation of the Volume Knob.

DA-2125
MODE
Mono
Stereo
POWER
IR AUTO ON
Input
Digital
Input 1 SOURCE
OUTPUT
AC 120V-60Hz
Fuse: T8A/250V
Power Consumption: 560W
Banana Plug
Make sure binding posts are tight-
ened then push in banana plug.
Be sure to maintain polarity (Speaker + to Amplier + , Speaker - to Amplier -)
Bare Wire
Rotate binding post counter-clock-
wise to reveal post. Strip back 3/8”
insulation from cable. Tightly twist
copper wire and wrap around post.
Rotate binding post clock-wise to
tighten.
5
Product Features (Cont.)
Motorized Volume Knob (cont.)
When using the unit in combination with external volume controls (see gures 2, 3, and 4 in the Speaker
Connection section), it is best to set and leave the Motorized Volume Knob to a level that equals the maxi-
mum listening level you want in the rooms that contain the speakers. In other words, while playing your
favorite source, start with the Motorized Volume Knob turned all the way down (counter-clockwise) and the
volume knobs on the volume controls turned all the way up. Then, gradually turn up the Motorized Volume
Control until the maximum listening level is achieved. In this way, the amplier is never using more power
than is ever necessary and the volume for each pair of speakers can be adjusted using the external volume
controls.
Speaker Cable Connections
Mode Switch: Stereo - When in the “Stereo” position, Left channel sound will come from the left set of red & black
speaker wire connectors & Right channel sound will come from the right set of red & black speaker wire connectors,
resulting in standard stereo sound output. MONO – When in the “MONO” position, the Left & Right channel inputs
will be merged into a combined, “mono” signal and all of the sets of red & black speaker wire connectors will output
the same sound.
Source Output Connectors: This is a line-level “pass-through” connector. The line-level signal from any select-
ed source is automatically sent out through these connectors. This is handy if you want to “daisy-chain” the signal
into another amplier or a as a source input into a whole-house system, without having to use RCA Y-adapters.
Mode
Switch
5 Stereo Inputs Source Output Two pairs of 5 way binding
posts Speaker Terminals
(A, B or A+B)
Power Cord Input
External Fuse
Power Selection Switch Digital Optical Input
Infrared (IR) Recieving Eye
for Remote Control
Speaker Output Buttons
(A, B or A+B)
Motoreized Volume Knob
(rotate manually or via remote control)
Source Selection Buttons
(select one - manually or via remote control)
Power Indicator Light
Power Button

6
123
456
0
On
Off
Source Selection
BASSTREB
TONE
MUTE
VOL
PWR
Product Features (cont.)
Remote Control Features
In addition to Power On/Off, Volume Level, and Source Selection, the remote control can be used
for tone control. While playing your favorite music, aim the Remote Control at the IR Receiving
Eye and adjust the bass and treble up or down until the sound is to your liking. Once set, the tone
will remain with these settings until they are again adjusted or until the “0” tone button is pressed.
Pressing the “0” button returns the treble and bass levels to their fac-
tory setting of a “at” response.
Mute is also available via the Remote Control for temporarily muting all
speaker output. Press the mute button again to return to music listen-
ing. The indicator light on the volume button will blink when the volume
is muted.
Also note that the Remote Control has separate Power On and Off
buttons. These are helpful when programming a “learning remote
control” and subsequently programming macros for turning the unit ON
or OFF. Note that these buttons are only active when the Power selec-
tion switch located on the back of the unit is in the REMOTE position.
Rack-Mounting Capability
The DA-2125 has pre-drilled screw holes to accept HTD 2U Mount-
ing Brackets (sold separately) for mounting the DA-2125 in a standard
rack.
Speaker Connections
Figure 1 - Two Pairs of Speakers, No External Volume Control
Two pairs of 8 ohm speakers can
be connected to the DA-2125
without the need for impedance
matching stereo volume controls.
Figure 1 shows one pair of 8 ohm
speakers connected to the A-side
and one pair of 8 ohm speakers
connected to the B-side. Either A,
B, or A and B can safely be se-
lected on the front of the DA-2125.
Alternatively, you could connect
both pairs of speakers to A or B.
The resulting impedance would be
4 ohms which is acceptable as long as no speakers are connected to the other side.
Figure 2 and Figure 3- Two Pairs of Speakers with External Volume Control(s)
Figure 2 shows one impedance matching stereo volume control connected to two pairs of 8 ohm
speakers. Figure 3 shows two impedance matching stereo volume controls each connected to one
pair of 8 ohm speakers. In both cases the impedance switches on the volume controls are set
to the "X1" position (times one equals no impedance correction). In both cases, the resulting
impedance is 4 ohms which is acceptable as long as the speakers are only connected to A or B,
not both.
Figure 1

X2
X2
X2
Figure 4
pass through one volume control). The total number of volume controls is irrelevant.
*While it is possible to connect more than four pairs of speakers to the DA-2125 by increasing the impedance matching
multiple on the volume controls, better performance is achieved by using multiple DA-2125s or a multi-channel amplier
when connecting ve or more pairs of speakers.
7
X1
X1
Figure 3
X1
Figure 2
Speaker Connections (cont.)
Figure 4 - Multiple Pairs of Speakers with Multiple Impedance Matching Stereo Volume
Controls*
When connecting more than two pairs of 8 ohm speakers to the DA-2125, it is necessary to use
impedance matching volume controls in order to correct for the impedance load placed on the am-
plier. Figure 4 shows four pairs of speakers connected to the DA-2125. Two pairs are connected
to the A-side and two pairs are connected to the B-side. In order to operate both A and B simul-
taneously, the minimum impedance load on each side must be 8 ohms. When two pairs of 8 ohm
speakers are connected in parallel (as shown), the impedance load is cut in half to 4 ohms. By
setting the impedance matching stereo volume controls to X2, the impedance is brought back up to
a safe level of 8 ohms.
Alternatively, you could also connect four pairs of speakers to the A-side or B-side only, and still
leave the volume control(s) set to X2. The resulting impedance will be 4 ohms which is acceptable
when only connecting to the A or B side. Note that it is the total number of speakers that are con-
nected to the same amplier that determines this position (as long as all speakers at some point

8
Warranty
All HTD electronics carry a two-year parts and labor warranty. Details can be found at www.htd.com/info/warranty.
Warranty registration occurred automatically at the time your order was placed. There is no need to complete or
mail in additional paperwork.
If you have any questions, we can be reached at...
[email protected] or toll free 1-866-HTD-AUDIO (483-2834)
Home Theater Direct, Inc.
www.htd.com
Expert Support:
Toll free: 866-HTD-AUDIO (483-2834)
[email protected]
Specications:
Stereo input sources
8 ohms RMS Watts Per Channel (both channels driven)
4 ohms RMS Watts Per Channel (both channels driven)
Total Harmonic Distortion (THD) 20 Hz - 20 kHz
8 ohms
4 ohms
Peak current per channel
Frequency response
Dimensions (HxWxD)
Net Weight
6
125
150
.04%
.06%
30 Amps
5 Hz - 65 kHz
3.75” x 16.5” x 14”
21 lbs.