Page 1
Multi-Channel Power Amplifiers
Operating Manual
Chann el 1 Chann el 2 Channel 3 C hannel 4 Cha nnel 5 Cha nnel 6
Prot ect
Thermal
Clip
Signal
Powerflex
Power
Powerflex
6250
Chann el 1 Chann el 2 Channel 3 C hannel 4
Prot ect
Thermal
Signal
Clip
Power
Powerflex
4400
ASHLY AUDIO INC.
847 Holt Road Webster, NY 14580-9103 Phone: (716) 872-0010
Toll-Free: (800) 828-6308 Fax: (716) 872-0739
www.ashly.com
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Operating Manual - Powerflex Multi-Channel Power Amplifier
Table Of Contents
1 INTRODUCTION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
2 UNPACKING . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
3 AC POWER REQUIREMENTS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
3.1 AC Voltage Requirements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
3.2 Current Requirements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
3.3 AC Grounding & Earth Grounding . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
4 CABLE REQUIREMENTS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
4.1 Input Cables . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
4.2 Output Cables . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
5 RACK-MOUNTING REQUIREMENTS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
5.1 Mechanical . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
5.2 Cooling . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
5.3 Grounding . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
6 FRONT PANEL INDICATORS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
7 REAR PANEL FEATURES . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
7.1 Input Connectors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
7.2 Input Ground Switch . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
7.3 Multi-Channel Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
7.4 Input Level Controls . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
7.5 Stereo/Mono Switches . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
7.6 Dual Channel Mode/Bridge Mode Switches . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
7.7 50Hz Low Cut Switches . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
7.8 Loudspeaker Output Connectors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
7.9 AC Inlet . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
8 SELF-PROTECTION FEATURES . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
8.1 Power Supply Undervoltage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
8.2 Power Supply Overvoltage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
8.3 Output Overcurrent . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
8.4 Heat Sink Overtemperature . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
8.5 Unacceptable DC or High Frequency Output Content . . . . . . . . . . . . . . . . . . . . 10
8.6 AC Power Interruption . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
9 TYPICAL APPLICATIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
9.1 Individual Channel Setup . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
9.2 Dual Mono Setup . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
9.3 Bridged Mono Setup . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
9.4 Typical PA Setup . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
2
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Operating Manual - Powerflex Multi-Channel Power Amplifier
10 DESIGN THEORY . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
11 TROUBLESHOOTING TIPS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
11.1 No Audio Output . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
11.2 Distorted Sound . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
11.3 Hum or Buzz Noise . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
12 DIMENSIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
13 SPECIFICATIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
14 WARRANTY INFORMATION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
Caution:
This power amplifier can produce dangerous output voltage levels, high power levels,
and high sound pressure levels in loudspeakers. In order to minimize the risk of injury, damage, or
hearing loss, please read the entire owner’s manual before connecting to a sound system.
CAUTION
RISK OF ELECT R I C SH O C K
DO NOT OPEN
The lightning flash with arrowhead symbol,
within an equalateral triangle, is intended to alert the
user to the presence of uninsulated "dangerous voltage" within the product's enclosure that may be of sufficient magnitude to constitute a risk of electric shock
to persons.
TO REDUCE THE RISK OF ELECTRIC SHOCK, DO NOT REMOVE COVER. NO USER SER-
VICEABLE PARTS INSIDE. REFER SERVICING TO QUALIFIED SERVICE PERSONNEL.
TO REDUCE THE RISK OF FIRE OR ELECTRICAL SHOCK, DO NOT EXPOSE THIS
APPLIANCE TO RAIN OR MOISTURE.
angle is intended to alert the user to the presence of
important operating and maintenance instructions in
the literature accompanying the device.
The exclamation point within an equalateral tri-
TO REDUCE THE RISK OF FIRE, REPLACE ONLY WITH SAME TYPE FUSE.
REFER REPLACEMENT TO QUALIFIED SERVICE PERSONNEL.
WARNING: THIS APPARATUS MUST BE EARTHED THROUGH THE SUPPLIED
POWER LINE CORD
3
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Operating Manual - Powerflex Multi-Channel Power Amplifier
1. INTRODUCTION
The Ashly Po werflex amplif iers combine the effi-
ciency of a MOSFET high-speed switching output stages
with the sophistication of modern microprocessors and DSP
technology to produce a multi-channel amplifier with unprecedented versatility and power in a single 3RU package.
Although similar to other amplifiers with class D
output stages, Powerflex amplifiers employ internal microprocessor and DSP algorithms to optimize output
switching characteristics and eliminate the usual harshness
associated with high-frequency audio in standard class D
amplifiers. This optimization results in a spread-spectrum
switched output that varies with input amplitude and frequency, and minimizes radiated emissions by eliminating
the single-frequency high-energy radiated interference
normally associated with switching outputs. The use of a
simple linear power supply removes another potential
source of radio-frequency interference, an important consideration as racks become more and more heavily populated with digital signal processing equipment. A small
switching supply using flyback topology provides an efficient power source for logic, protection, pre-amplifier and
indicator circuits.
To assure reliable operation, the usual protection
from excessive high-frequency, DC offset, and thermal
overload is supplemented by power supply undervoltage,
power supply overvoltage, and output overcurrent detection, all monitored and controlled by the latest in miniaturized microprocessor technology.
In sum, Ashly Powerflex amplifiers combine the
best of the new digital technologies with the best of the
traditional analog technologies to provide a product that
will supply clean sound at full output from every channel
while generating minimal heat, thus increasing the reliability of every other piece of equipment in a rack as well
as preserving its own.
2. UNPACKING
As a part of our system of quality control, every
Ashly product is carefully inspected before leaving the
factory to ensure flawless appearance. After unpac king,
please inspect for any physical damage. Save the shipping carton and all packing materials, as they were carefully designed to reduce to minimum the possibility of
transportation damage should the unit again require packing and shipping. In the event that damage has occurred,
immediately notify your dealer so that a written claim to
cover the damages can be initiated.
The right to any claim against a public carrier can
be forfeited if the carrier is not notified promptly and if
the shipping carton and packing materials are not available for inspection by the carrier. Save all packing materials until the claim has been settled.
3. AC POWER REQUIREMENTS
3.1 Voltage Requirements
The Powerflex amplifiers can be operated from
nominal 120VAC or 240VAC, 50/60Hz mains. This is userconfigurable by changing the insert in the AC Inlet (See
section 7.9). The power connector on the amplifier accepts
a standard IEC-320 receptacle.
For nominal 120VAC operation, the power cord
should be three-conductor, rated for at least 13A (16AWG).
The line fuse should be type MDA, 12A.
For nominal 240VAC operation, the power cord
should be three-conductor, rated for at least 10A (18AWG).
The line fuse should be type MDA, 10A.
3.2 Current Requir ements
1.) Idle (no audio):
Powerflex 6250 Powerflex 4400
120V: 0.81A 120V: 0.9A
240V: 0.42A 240V: 0.5A
2.) With typical audio inputs:
8Ω loads on all channels
120V: 4A 120V: 4.6A
240V: 2A 240V: 2.3A
4Ω loads on all channels
120V: 6.5A 120V: 7.0A
240V: 3.3A 240V: 3.5A
70 Volt systems - (Powerflex 6250 Only,
3 channels Bridged Mono)
120V: 6.5A
240V: 3.3A
Powerflex amplifiers consumes less than 12 amps
when all channels operate at 1/8 power into rated (4 ohm)
loads. This condition satisfies the UL, CSA and building
electrical code requirements for a piece of audio equipment not to consume more than 80% of the current available when plugged into a grounded 15 amp outlet and
operated at 1/8 of maximum power.
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Operating Manual - Powerflex Multi-Channel Power Amplifier
3.3 AC Grounding Requirements
T o reduce the risk of ground loop hum, all system
ground references should originate at the same point in
your A C po wer distribution. Do not remov e the amplifier’ s
ground pin, as it creates a potential shock hazard.
4. CABLE REQUIREMENTS
4.1 Input Cables
Be sure to use shielded cable whether balanced or
unbalanced. Shielding which is properly grounded will
protect the signal from outside electrical interference such
as RF, fluorescent lighting, and computer/display emissions. As a general rule, unbalanced or single-ended (tipsleeve) lines of less than 10 feet are satisf actory , but gr eater
distances or noisy field environments require a balanced
signal. Avoid running input lines in close proximity or
parallel to long speaker lines, AC power cables, or power
transformers, as this may generate hum or oscillation.
4.2 Output Cables
Powerflex amplifiers are capable of delivering
high levels of output current, therefore the wire gauge used
for speaker cables is particularly important. Inadequate
wire gauge can add significant resistance to the speaker’s
own impedance, especially over long distances, reducing
the power which is actually delivered to the speaker. It
could also result in a decreased damping factor and possible fire hazard. Since power at the speaker load is of
primary concern in system design, we hav e included a table
to best determine appropriate wire gauge for your application. The following table lists the resistance per 100
feet of common copper wire gauges, and also gives the
percentage of the speaker load power which would be lost
in an arbitrary 100 ft run of different gauges of 2-conductor copper speaker wire.
power loss in the cable would be half that of a 100 ft run
of #14 wire as shown in the table, or 1.6% of 150W, which
is an insignificant 2.4 watts. However, if you were to run
200 ft of 18 ga. cable to a 4Ω load, the loss would be twice
that of the 100 ft run shown in the table, or 32.6% of 250W ,
which is 81.5 watts lost as heat. Always be sure to use
adequate gauge speaker wire.
5. RACK-MOUNTING REQUIREMENTS
5.1 Mechanical
Powerflex amplifiers are designed to fit in standard 19-inch equipment racks. The front panel rack-mount
ears are sufficiently strong for most applications, howev er
if you desire further integrity for mobile racks, we recommend using the four additional holes in the back of the
chassis for supplemental rear-mounting (see dimensional
drawing for details).
5.2 Cooling
Be certain that both the front and back of the rack
have unhindered access to free air flow. Fan direction is
from front to back. It is not necessary to leave empty space
above or below.
5.3 Grounding
In some installations where the sound system is
sensitive to RF noise or system-induced oscillation, it may
be necessary to ground the amplifier’s chassis to the rack
enclosure. This is accomplished using star type
lockwashers on the four rack mounting screws. These star
washers will penetrate through the amplifier’s paint to adequately ground the chassis to the rack.
Wire Gauge Ω/100ft 8Ω load 4Ω load
#8 .0605Ω 0.8% 1.5%
#10 .1018Ω 1.3% 2.5%
#12 .1619Ω 2.0% 4.0%
#14 .2575Ω 3.2% 6.4%
#16 .4094Ω 5.1% 10.2%
#18 .6510Ω 8.1% 16.3%
Table 4.1: Wire gauge resistance/power loss
This table expresses the power loss as a percent-
age of the load’s power rather than the total amplifier output power in order to accurately determine power loss at
other cable lengths. For example, if you plan to deliver
150 watts to an 8Ω load through 50 ft of 14 ga. cable, the
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Operating Manual - Powerflex Multi-Channel Power Amplifier
Channel 1 Channel 2 Channel 3 Channel 4 Channel 5 Channel 6
Protec t
Thermal
Clip
Signal
Power
Powerflex
6250
6. FRONT PANEL INDICATORS
6.1 Power Switch
When the unit is switched on there is a five sec-
ond delay, during which time the PROTECT circuit will
activate, disconnecting the speakers from the amplifier
output. When turning of f the amplifier , the load is removed
instantly, and the protect LED will briefly turn on as the
power supply discharges.
6.2 Signal Indicator
The signal present LEDs illuminate at an input
level of about 13mVrms (-35.5dBu).
6.3 Clipping Indicator
The clipping LEDs illuminate at an input level of
about 870mVrms (+1.0dBu), with all channels driven by
1KHz into 8Ω. This indicates that the signal processing
circuitry has determined output levels to be approaching
the available po wer supply rails and has begun to “soften”
signal peaks. Actual onset of “hard” clipping depends on
audio program and total load impedance and does not occur until the signal processing circuitry can no longer compensate, which means that signal integrity can be
maintained even if the clipping indicators illuminate for
short periods of time.
6.4 Thermal Status Indicator
The thermal LEDs illuminate when the tempera-
ture of any one of the heat sink extrusions reaches 85 to
90°C. Both channels of the affected amplifier module will
shut off until the measured temperature drops below a bout
70°C. The amplifier should be able to maintain proper
operation at an ambient room temperature of 50°C (122°F)
or less with typical audio program and all channels drive n
into 4Ω.
6.5 Protect Indicator
The protect LEDs illuminate when the fault monitoring microprocessor has determined that one of the following conditions exists:
- Power supply undervoltage
- Power supply overvoltage
- Output overcurrent
- Heat sink overtemperature
- Unacceptable DC output content
- Unacceptable high frequency output content
- AC power interruption
Because the signal processing module used in
Powerflex amplifiers processes two channels simultaneously , a fault in one channel will result in a pr otect condition for both channels processed by the same module,
ex. channels 1-2, 3-4, and 5-6 (6250 only). Thus there
will never be a case where only one of the amplifier channels is shown in protect mode. When a pair of protect
LED's are illuminated, internal relays have removed the
channel pair's speaker loads from the amplifier output and
connected the speakers to ground. If the fault is isolated
to one module (channel pair), the other channels will remain unaffected.
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7. REAR PANEL FEATURES
Operating Manual - Powerflex Multi-Channel Power Amplifier
* P ow erflex 6250 shown - P owerflex 4400
only has channels 1-4.
7.1 Input Connectors
The Powerflex inputs use 1/4" tip-ring-sleeve (TRS) phone jacks, balanced XLR jacks, and balanced two piece
"Euroblock" style connectors. The three types of connectors are wired in parallel and may be used balanced or unbalanced. Use the euro-block connectors to daisy-chain multiple amps together . Input XLR jacks are pin 2 hot (+),
meaning that a positive voltage applied to pin 2 will result in a positi ve output voltage across the speaker terminals. Pin
2 of the XLR jack is equivalent to the tip of the 1/4" TRS jack.
Balanced Inputs
It is recommended that balanced input connections
be used whenever possible to take full advantage of the
amplifier's common mode rejection properties, and to reduce
Tip (+)
Ring (-)
Sleeve (Ground)
Stereo Phone Plug
Balanced Connection
ground-loop problems. The (+) signal is on pin 2 of the XLR,
and the tip of the phone jack. The (-) signal is on pin 3 of the
XLR, and the ring of the phone jack. If a hum problem persists, try connecting a balanced signal to the Euroblock input
with the input cable's shield lifted at the amplifier end of the
cable (ie. no ground connection), but connected to ground at
the signal source. This eliminates potential ground currents
through the input cable yet preserves the benefits of shielding.
Unbalanced Inputs
If an unbalanced XLR input connection is used, pin 3
should be connected to input ground (pin 1). If the 1/4" input
2=(+)
3=(-)
1=(gnd)
-+
Tip (+)
Sleeve (Ground)
+-
Euroblock
Input Connector
Ground
Balanced Audio Connections
Mono Phone Plug
Unbalanced Connection
XLR Male
Balanced
Connection
jack is used unbalanced, the use of a mono (tip-sleeve) plug
will automatically tie the (-) connection to input ground. Note:
Never float the (+) or (-) input connection when using an un-
2=(+)
3=(gnd)
1=(gnd)
XLR Male
Unbalanced
Connection
balanced source. If connecting an unbalanced signal to the
Euroblock input, connect the signal to (+) and the cable shield
to both (-) and ground.
Signal (+)
(-) Input
Tied To
Ground
-+
Grou nd
+-
Euroblock
Input Connector
Unbalanced Audio Connections
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Operating Manual - Powerflex Multi-Channel Power Amplifier
Stereo
5 5 5
Mono
6
7
8
9
3
2
1
010
Ch2
Dual
Bridge
6
7
8
Ch.
3-4
9
50Hz
6
3
2
1
0410
Ch3 Ch4
(3-4 Mono)
Norm
LoCu t
*
Powerflex
1-2
50Hz
Ch.
2
Norm
LoCu t
3
1
5
0410
Ch1
(1-2 M ono)
6250 shown Powerflex
4400 only has
inputs 1-4.
Input
Ground
Float
Chassis
AC
(Mono)
115V
Ch3
(Mono)
(Mono)
Ch2Ch1 Ch4 Ch6
Ground
-+
Ch 1 In
(Mono)
+
--+
Ch 2 In Ch 3 In
7.2 Input Ground Switch
This switch separates internal circuit ground from
the chassis ground on all inputs. Ground connections from
an incoming signal are always connected to internal circuit ground, but float from the chassis ground as long as
the switch is out. Unless there are special circumstances
which require the circuit ground and chassis ground to be
connected, it is best to leave this switch out.
Stereo
Mono
3
7
8
2
9
1
010
Dual
Bridge
Ground
+
--+
Ch 4 In Ch 5 In
115V or 230V
50-60Hz
1400W
Replace Only With
Same Type Fu se.
Ref er To O wne r's M anual
For Proper Fuse Rating.
3
2
Ch.
5-6
1
0410
Ch5 Ch6
(5-6 M ono)
Norm
LoCu t
PUSHPUSHPUSHPU SHPUSH
5 5
6
7
8
9
50Hz
Ch5
Ground
(Mono)
6
(Mono)
7
8
9
+
Ch 6 In
Stereo
Mono
3
2
1
010
Dual
Bridge
PUSH
-
6
7
8
9
231
(-)(+)
In MONO Mode, the input signal connected to
channels 1, 3, or 5 are used to drive channels 2, 4, or 6
respectively, and the level controls for channels 1, 3, and
5 likewise control channels 2, 4, and 6. When switched to
Mono mode, channels 2, 4, or 6 level controls become inactive.
In BRIDGED mode, the level controls function
the same as in mono mode.
7.3 Multi-Channel Operation
The Powerflex 6250 is essentially three stereo
amplifiers in one chassis, for a total of up to six separate
channels. Similarly, the Po werflex 4400 is essentially two
stereo amplifiers in one chassis, for a total of up to four
separate channels. Thus, the following references to Stereo, Mono, or Bridged operation is with regard to each
pair of channels in the amplifier. For example, Channel 1
and Channel 2 together can provide stereo, mono, or
bridged operation, completely independent of Channels 34 or Channels 5-6 settings (6250 only).
7.4 50Hz Low Cut Switch
Each pair of channels has a 50Hz second order
(12 dB per octave) low-cut filter option which is applied
to both channels within the pair. When the switch is
pressed, the audio signal is -3dB at 50Hz, -15dB at 25 Hz,
-27dB at 12.5Hz, etc.
7.5 Input Level Controls
Input Level Controls attenuate input signal from
0dB down to -∞. For best performance, Ashly recommends
that the level controls be operated at full level (0 dB attenuation).
In STEREO mode, each level control corresponds
directly to the input signal on its respective channel.
7.6 Stereo/Mono Switch
Powerflex amplif iers are comprised of two (4400)
or three (6250) stereo amplifiers, each operating independently of the others, with Stereo/Mono switching available for each channel pair. If this switch is set to Stereo
mode, the channel pair operates as two discrete amplifiers, each with its own input connection and level control.
Switching to Mono mode allows one input (channel 1, 3, or 5) to drive both channels of a stereo channel
pair . Pressing the Mono switch disables the channel pair's
other input connection, as well as its level control. The
first channel's input and level control now determines the
signal to both channels.
7.7 Dual Channel/Bridge Mode Switch
Bridging a pow er amplifier is the process wher eby
two channels are supplied the same signal, with the second channel's phase inverted 180°. The speaker is then
connected across the (+) output connections of each channel, resulting in twice the power to the speaker that either
channel could deliver by itself. Since in Bridge Mode both
connections have voltage present, never connect or touch
either speaker wire to gr ound. In the Powerflex 6250, use
Bridge mode for 70V applications as well.
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Operating Manual - Powerflex Multi-Channel Power Amplifier
BRIDGE MODE:
From Two Red Posts.
Do Not Connect Either Output
*
Wire To Ground.
Take Output
Powerflex
6250 shown Powerflex
4400 only has
channels 1-4
with no 70V
output.
Ch1
(+)
(-)
Bridge/70V
+-
(+)
Ch2
(-)
(+)
Ch3
(-)
The Powerflex 6250 is capable of three channels
of bridged output, while the Powerflex 440 is capable of
two channels of bridged output. To use bridged mode,
first press MONO from the Stereo/Mono switch on the
channel pair to be bridged. This sends the same audio
signal to both channels. Then press BRIDGE from the
Dual/Bridge switch on the channel pair to be bridged. This
inverts the phase of the input signal to the second channel.
These two channels are now operating together in Bridged
Mono mode, and the output must be taken from the two
red binding posts corresponding to the bridged channel
pair Observe polarity by noting which red binding post is
(+) and which is (-)
Ashly Audio Inc.
Made In USA
Powerflex 6250
OUTPUTS
Bridge/70V
+-
move the power cord from the rear of the amplifier.
the fuse holder in the AC inlet and remove it.
tate until the new nominal mains voltage level indication
(115 or 230) is on top and properly oriented for reading.
inlet, making sure that it is plugged in all the way.
(+)
Ch4
(-)
(+)
Ch5
(-)
Dual Ster eo/Dual Mo no Mode :
150W/Cha n - 8
250W/Cha n - 4
Bridged Mono Mode:
500W Bridged - 8
Bridge/70V
+-
Ω
Ω
Ω
(+)
Ch6
(-)
1.) Unplug the amplifier from the wall and re-
2.) Using a small screwdriver as a lever, unlatch
3.) Remove the voltage selection insert and ro-
4.) Replace the voltage selection insert in the AC
7.8 Speaker Outputs - Binding Posts
Dual binding posts provide connections for the
speaker outputs. In addition to using the banana-type plug,
the binding posts have a slotted entry-way for wire-crimped
spade terminals. In BRIDGE/70V mode, the channel 1, 3,
or 5 red binding post is the (+) in-phase speaker output
terminal and the channel 2, 4, or 6 red binding post becomes the (-) out-of-phase speaker terminal.
CAUTION! NEVER CONNECT THE TWO RED
BINDING POSTS TOGETHER OR CONNECT EITHER
RED BINDING POST TO A BLACK BINDING POST!
7.9 AC Inlet
Powerflex amplifiers can be configured by the customer for operation at either 115VAC or 230VAC mains.
Switching from one to the other simply requires the following steps:
5.) Replace the fuse with the appropriate size (see
#6 below), and press the fuseholder back into the AC inlet
until it latches.
6.) Using a power cord of the appropriate size
and with the appropriate terminations, plug the cord into
the rear of the amplifier and then into the wall. The
Powerflex amplifier is no w ready for use at the new mains
voltage.
If the mains voltage is 110-125VAC, the required
fuse is MDA 12, 250V, and the required power cord is 3wire grounded, 13 Amp (16AWG) minimum.
If the mains voltage is 220-250VAC, the required
fuse is MDA 10, 250V, and the required power cord is 3wire grounded, 10 Amp (18AWG) minimum.
9
Page 10
Operating Manual - Powerflex Multi-Channel Power Amplifier
8.3 Output overcurr ent - more than 15 to 20 amps
8. SELF-PROTECTION FEATURES
Powerflex amplifiers contain circuitry to self-protect during extreme fault conditions. These fault conditions are:
being drawn from any output. Possible causes would be
total load on the affected output exceeding recommendations (disconnect some speakers), or a short circuit on one
of the outputs driven by the affected module (inspect
speaker wiring for proper connection).
1.) Power supply undervoltage
2.) Power supply overvoltage
3.) Output overcurrent
4.) Heat sink overtemperature
5.) Unacceptable DC or high frequency output content
6.) AC power interruption
Except for AC power interruption, the detection
of any fault will result in the activation of protection circuitry on a particular module, which consists of two channels. That is, a short circuit on the output of channel 1
will result in both channel 1 and channel 2 entering protect mode. This is because the signal processing module,
which processes both channels simultaneously, does not
distinguish between the two channels within a channel pair
when processing a fault.
An AC power interruption will result in all channels entering protect mode simultaneously, just as if the
amplifier is being turned off.
In all cases, the amplifier will restart the signal
processing module after a short delay and will reconnect
the speakers after several seconds if no further fault conditions exist. This allows the servo circuitry to bring any
residual DC offsets to zero before speakers are connected.
Specific conditions resulting in a fault are as follows:
8.1 Power supply undervoltage - less than about
55 volts on the either supply rail. Possible causes would
be total load on the outputs exceeding recommendations
(remove some speakers - 4Ω load min, 8Ω min bridged),
low AC mains voltage (reduce extension cord length or
increase wire size, or switch to an AC mains circuit more
capable of supporting the amplifier's po wer requirements),
or improper AC inlet mains voltage setting (make sure
nominal A C mains v oltage matches the number in the viewing window on the AC inlet).
The above conditions are checked by the signal
processing module on a switching cycle by switching c ycle
basis and are therefore monitored as often as a million or
more times a second, allowing protection well before destructive conditions have time to cause part failure.
8.4 Heat sink overtemperature - a measured heat
sink extrusion temperature of more than 85 to 90 degrees
C. The three-speed fan will switch to medium speed at an
extrusion temperature of 45 to 50 degrees C, and to high
speed at a temperature of 70 to 75 degrees C. The
overtemperature fault will clear itself when the measured
temperature is below about 70 degrees C. The fan will
operate at low speed below about 50 degrees C.
8.5 Unacceptable DC or high frequency output
content - a DC offset in the output signal of more than a
few hundred millivolts indicates module failure, and will
trigger a DC protect fault. High frequency (20kHz to
100kHz) in the output at high amplitudes can cause speaker
damage and causes a fault condition more or less rapidly
as frequency and amplitude vary.
These two conditions (DC and HF) are tested by
the same circuit so the exact cause cannot be isolated. If
the fault condition persists after disconnecting all inputs
and outputs from the amplifier, there is probably a module
failure requiring service. Note: the self-testing cir cuit may
take as long as 30 seconds to recover from this fault, so be
sure to give the amplifier enough time to reset itself. If
after 30 seconds the module has recovered, begin plugging in one input and output at a time in an effort to isolate a system high-frequency or oscillation problem.
8.6 AC power interruption - a dropout (or bro wnout of sufficient magnitude) of more than one half mains
line cycle and less than one whole cycle in duration.
8.2 Power supply overvoltage - more than about
92 volts on either supply rail. Possible causes would be
high A C mains v oltage (change to an A C mains circuit with
voltage within the amplifier's stated requirements) or improper AC inlet mains voltage setting (make sure nominal
AC mains voltag e matches the number in the viewing window on the AC inlet).
10
Page 11
Operating Manual - Powerflex Multi-Channel Power Amplifier
H
9. TYPICAL APPLICA TIONS
The Powerflex 6250 is essentially three stereo amplifiers in one chassis, each with dual stereo, dual mono, and
bridged mono capabilities, while the Powerflex 4400 is two stereo amplifiers (four channels), but with more power per
channel than the 6250. The ability to easily mix and match various configurations is what puts the "flexibility" in
Powerflex. Input connections can be 1/4" phone plug, XLR, or hard-wired with two-piece Euroblock connectors, while
speaker outputs can be either "banana" type plugs or wire crimped spade terminals. Note: The Powe rflex 6250 is used
for the following application details, but the 4400 is used in a similar fashion, to a maximum of four channels.
9.1 Individual Channel Setup
Six Channel Setup
Input Section:
Up to Six Different Inputs
Stereo/Mono Switches - Out
Dual Bridge Switches - Out
Levels Controls - Used Per Input Channel
Stereo
5
5 5 5 5 5
6
6
Mo no
3
3
7
2
Ch.
1-2
1
0410
Ch1
(1-2 Mono)
No r m
LoC u t
50Hz
(Mono) (Mono) (Mono)
Input
Ground
Float
Chassis
" $
7
8
2
8
Ch.
9
Ch 1 In Ch 2 In
(Mono)
3-4
9
1
010
Ch2
Dual
Bridge
50Hz
Ch2Ch1 Ch3 Ch4 Ch5 Ch6
+
Grou nd
-
-+
! #
Up To Six Different Amplifier Inputs
9.2 Dual Mono Setup
Stereo
6
Mo no
3
3
7
2
8
2
9
1
1
0410
010
Ch3 Ch4
(3-4 Mono)
Dual
No r m
LoC u t
Bridge
+
Grou nd
-+
Ch 3 In Ch 4 In
(Mono) (Mono)
-
6
7
8
Ch.
5-6
9
50Hz
3
2
1
0410
Ch5 Ch6
(5-6 Mono)
No r m
LoC u t
Grou nd
-+
Ch 5 In Ch 6 In
Possible Applications:
Multiple Zone Systems
Three Pairs Of Stud io Mon it ors
Multiple Stage Monitors
25V Distributed Systems (6250 Only)
Stereo
6
6
Mo no
3
7
7
8
2
+
1
010
Dual
Bridge
-
8
9
9
(+)
Ch1
(-)
! " # $
Du a l Mono Setup
(dual stereo)
Ashly Audio Inc.
Made In USA
Power flex 6250
Bridg e/70V
+-
(+)
Ch2
(-)
Speaker Outputs
Minimum Speaker Load Per Channel = 4
OUTPUTS
Bridg e/70V
+-
(+)
Ch3
(-)
- Up To Six Different Outputs
Multi-Media Systems
Surround Sound
Three Way Biamplification
Stereo T ria mplifica tion
Bridg e/70V
+-
(+)
(+)
Ch4
Ch5
(-)
(-)
Ω
(+)
Ch6
(-)
Input Section:
Up to Three Different Inputs
Stereo/Mono Switches - In
Dual Bridge Switches - Out
Levels Controls - Only Channels 1, 3, or 5 Used
Stereo
5 5 5 5 5
5
6
6
Mo no
3
3
7
2
Ch.
1-2
1
0410
Ch1
(1-2 Mono)
No r m
LoC u t
50Hz
(Mono) (Mono) (Mono)
Input
Ground
Float
Ch assis
7
2
8
8
Ch.
9
Ch 1 In Ch 2 In
(Mono)
3-4
9
1
010
Ch2
Dual
Bridge
50Hz
Ch2Ch1 Ch3 Ch4 Ch5 Ch6
+
Grou nd
-+
-
Stereo
6
Mo no
3
3
7
2
2
8
9
1
1
0410
010
Ch3 Ch4
(3-4 Mono)
No r m
Dual
LoC u t
Bridge
+
Grou nd
-+
Ch 3 In Ch 4 In
(Mono) (Mono)
-
6
7
8
Ch.
5-6
9
50Hz
3
2
1
0410
Ch5 Ch6
(5-6 Mono)
No r m
LoC u t
Grou nd
-+
Ch 5 In Ch 6 In
! #
(An Input Can Be Parallel Connected
To Other "Non-Partner" Channels by
ard-Wire Jumping the Euroblock Connectors)
Amplifier Inputs
Possib le Applications:
Multiple Zone Systems
Three Different Stage Monitor Mixes
Dual-Mono FOH Tri-Amplification
Stereo
6
6
Mo no
3
7
7
2
8
+
1
010
Dual
Bridge
-
8
9
Ashly Audio Inc.
Made In USA
Powerflex 6250
(+)
Ch1
(-)
Bridge/70V
+-
(+)
Ch2
(-)
(+)
Ch3
(-)
OUTPUTS
Bridge/70V
+-
(+)
Ch4
(-)
(+)
Ch5
(-)
Bridge/70V
+-
(+)
Ch6
(-)
9
! " # $
Channels 1 & 2
From Cha nne l 1 Inpu t
Minimum Speaker Load Per Channel = 4
Channels 3
From Cha nne l 3 Inpu t
&
4
From Cha nne l 5 Inpu t
Channels 5
Ω
&
6
11
Page 12
Operating Manual - Powerflex Multi-Channel Power Amplifier
9.3 Bridged Mono Setup
Bridged Mono Setup
Input Section:
Up to Three Different In p u ts
Stereo/Mono Switches - In
Dual/Bridge Switches - In
Levels Controls - Only Channels 1, 3, or 5 Used
Stereo
5
5 5 5 5 5
6
6
Mono
3
3
7
2
Ch.
1-2
1
0410
Ch1
(1-2 Mono)
Nor m
LoC ut
50Hz
(Mono) (Mono) (Mono)
Input
Ground
Float
Chassis
7
8
2
8
Ch.
9
Ch 1 In Ch 2 In
(Mono)
3-4
9
1
010
Ch2
Dual
Bridge
50Hz
Ch2Ch1 Ch3 Ch4 Ch5 Ch6
+
Grou nd
-
-+
! #
Stereo
6
Mono
3
3
7
2
8
2
9
1
1
0410
010
Ch3 Ch4
(3-4 Mono)
Nor m
Dual
LoC ut
Bridge
+
Grou nd
-+
Ch 3 In Ch 4 In
(Mono) (Mono)
(Mono) (Mono)
-
6
7
8
Ch.
5-6
9
50Hz
3
2
1
0410
Ch5 Ch6
(5-6 Mono)
Nor m
LoC ut
-+
Ch 5 In Ch 6 In
Amplifier Inputs
Grou nd
Possible Applications:
70 Volt Constant Voltage Systems (6250 Only)
Subwoofers
High Powered Monitors
High Powered Full Range PA Speakers
Stereo
6
6
Mono
3
7
7
8
2
+
Dual
Bridge
-
1
010
8
9
(+ )
Ch1
(-)
Bridged Channels 1 & 2
From Channel 1 Input
Ashly Audio Inc.
Made In USA
Powerfl ex 6250
(+ )
Ch3
(-)
OUTPUTS
Bridg e/70V
+-
(+ )
Ch4
Bridg e/70V
+-
(+ )
Ch5
(-)
(-)
Bridg e/70V
+-
(+ )
Ch2
(-)
(+ ) (-) (+) (-) (+) (- )
Bridged Channels 3 & 4
From Channel 3 Input
Bridged Channels 5 & 6
From Channel 5 Input
Minimum Speaker Load Per Bridged Channel Pair = 8
(+ )
Ch6
(-)
Ω
9
9.4 Typical PA Setup
Stereo
5
5 5 5 5 5
6
6
Mo n o
3
3
7
2
Ch.
1-2
1
0410
Ch1
(1-2 Mono)
No r m
LoC u t
50Hz
(Mono) (Mono) (Mono)
Input
Ground
Float
Chassis
7
8
8
2
Ch.
9
Ch 1 In Ch 2 In
(Mono)
3-4
9
1
010
Ch2
Dual
Bridge
50Hz
Ch2Ch1 Ch3 Ch4 Ch5 Ch6
-+
+-
Grou nd
! # $
Subwoofer
Input
(Brid ged Mono)
Full Range
Input
(Dual Mono)
Stereo
6
Mo n o
3
3
7
8
2
2
9
1
1
0410
Ch3 Ch4
(3-4 Mono)
Dual
No r m
Bridge
LoC u t
-+
+-
Grou nd
Ch 3 In Ch 4 In
(Mono) (Mono)
6
7
8
Ch.
5-6
9
010
50Hz
(Dual Stereo)
6
3
7
8
2
9
1
0410
Ch5 Ch6
(5-6 Mono)
No r m
LoC u t
-+
+-
Grou nd
Ch 5 In Ch 6 In
Monitor
Inputs
Stereo
Mo n o
3
2
1
010
Dual
Bridge
6
7
8
9
Ashly Audio Inc.
Made In USA
Power flex 6250
Brid ge/70V
+-
(+)
Ch1
(-)
Subwoofer
Bridged Output
Ω
Minimum
8
(+)
Ch2
(-)
OUTPUTS
Brid ge/70V
+-
(+)
Ch3
(-)
Dual Full Range
Outputs
4Ω Min/Channel
(+)
(+)
Ch4
Ch5
(-)
(-)
Separate Monitor
4Ω Min/Channel
Brid ge/70V
+-
(+)
Ch6
(-)
Outputs
12
Page 13
Operating Manual - Powerflex Multi-Channel Power Amplifier
10. DESIGN THEORY
Powerflex amplifiers are based on stereo driver
modules that use digital processing to generate a spreadspectrum switching pattern between about 200KHz and
1.5MHz, depending on input signal amplitude and frequency. This overcomes the self-limiting and inherent
weakness in traditional class D fixed-frequency PWM
amplifiers, and produces an output with THD+N numbers
comparable to class A and class AB linear amplifiers. (see
Specification Notes at end of this section)
In Powerflex amplifiers, the input signal is received by a single operational amplifier configured as a
difference amplifier to reduce common-mode ef fects from
sources located at a distance. This difference amplifier has
a gain of 2.74 which allows the use of less gain later in the
system, improving overall system noise performance.
The amplified signal, based on the position of
various selector switches, either bypasses or is processed
by a two-pole high-pass filter with rolloff at 50Hz, and
then passes through the attenuating potentiometer. The
attenuated signal is buffered and passed to the amplifier
module along with a zero-volt reference.
The amplifier module receives the attenuated signal with a unity gain differential amplifier to eliminate
common-mode interference picked up within the amplifier chassis. The signal is then added to a small DC offset
signal opposite in polarity to any DC offset on the
Powerflex output bridge and adjusted by the digital processing module as described above. The digital processing module, which also generates FET drive signals, has a
voltage gain of 11.7 for a total system voltage gain of 32.
The drive signals generated by the processing module are
fed to a pair of high-current MOSFET transistors, and the
switched output of these transistors is filtered and applied
to the speaker outputs. Fault conditions such as overvoltage, undervoltage, and output overcurrent are measured
by the module and therefore affect a stereo pair of channels regardless of whether the fault actually exists on both
channels processed in the module. Since every action applied to protect the digital processing module affects both
channels being processed, other fault conditions are not
separated by channel, but rather by amplifier module.
Specification Notes: Due to its spread spectrum out-
put switching pattern, the output signal of a Powerflex ampli-
fier contains significant dynamic frequency content* far outside
the audio band, which makes no difference to audible performance, but which makes heavily bandwidth-limited** measurement of amplifier noise and distortion characteristics manda tory.
11. TROUBLESHOO TING TIPS
11.1 No A udio Output
1.) Power LED not lit:
Line fuse is blown or power outlet is dead.
IF LINE FUSE IS BLOWN, REPLACE ONLY
WITH SAME TYPE AND RATING FUSE.
2.) Power LED is lit but Protect LEDs stay on:
Amp module is in protect mode. Speakers have
been disconnected from amplifier output and connected to
ground until the protect fault is corrected. See section 8
for a complete explanation of protect fault conditions. Output overcurrent, overvoltage and undervoltage faults will
reset in about eight seconds once the fault condition is removed, while excessiv e DC offset or high frequency f aults
take about 30 seconds to reset.
Speaker Impedance: The Powerflex amplifier
may go into self-protect at high output levels if the actual
speaker load impedance is much less than 4 ohms. To calculate speaker impedance for a given combination of direct-coupled speakers, use Ohm's law as applied to series
and/or parallel resistor networks, where each speaker (for
this purpose) can be thought of as a single resistor, using
DC resistance measurements.
Simply stated, speakers connected in series will add
together their impedance. Conversely, two speakers connected in parallel will result in half the impedance, three
parallel speakers a third the impedance, four speakers a
fourth, and so on, assuming the speaker impedances are all
the same. Don't use mismatched impedances in parallel.
When using paralleled speakers, the available amplifier
power for that channel is evenly divided among speakers,
so 100 watts driving two parallel speakers of equal impedance provides 50 watts to each speaker, etc. Combining
series/parallel speaker connections is common practice, but
if not sure, contact your dealer or Ashly tech support.
3.) Thermal LED and Protect LEDs stay on:
Amp module is in thermal protect mode and needs
to cool. The fan will continue to run while in thermal protect, and other modules will continue to function. See section 8.4 for details.
4.) Power LED lit but no Signal LED activity
*variable 200KHz to 1.5MHz
**greater than 48dB/octave above 22kHz
There is no input signal applied or input level controls are turned down.
13
Page 14
Operating Manual - Powerflex Multi-Channel Power Amplifier
11.2 Distorted Sound
1.) Clip LED is flashing regularly
Amplifier is being overdriven. Turn down the input level control, or reduce the output level from the signal source.
2.) Clip LED is not flashing at all
Amplifier input signal may be exceeding input
headroom, which is greater than +12dBu, or 3.4V rms
(measured using continuous 1kHz sine wave). Incoming
signal level higher than +12.8 dBu will cause distortion in
the amplifier. Turning down the input level controls will
not eliminate distortion if the input headroom is e xceeded.
Turn down the output level of the device driving the amplifier instead.
Additionally, an input signal may already be distorted before it gets to the amp. Check to see if a piece of
equipment in the signal chain before the amp is clipping.
For best performance, the amplifier should be operated with
input levels fully CW. Also check for damaged speaker
drivers that could cause distorted sound.
11.3 Hum or Buzz Noise
Be sure that the power cord’ s 3-prong plug is connected to a properly earth-grounded outlet. Lifting the
grounding third prong may not improve hum or buzz and
can create a potential shock hazard.
Hum is usually caused by ground currents flowing between different pieces of equipment. Ground currents can be minimized by using a single point AC ground
for the sound system, and by using balanced connections
with quality cable throughout the audio path.
Buzz, as well as certain audible high frequency
tones, can be caused by environmental emissions such as
lighting dimmers, neon lights, or computer equipment. Use
balanced connections, and try moving the amplifier, wiring, lighting, or other equipment to different locations to
isolate the source of the noise.
Sections 3.3, 5.3, 7.1, and 7.2 further discuss issues related to grounding and noise problems.
12. POWERFLEX DIMENSIONS
13.54"
16.94"
18.5"
2.25"
13.18"
1.25"
14
5.19"
4.75"
2.25"
Channel 1 Channel 2 Channel 3 Channel 4 Channel 5 Channel 6
Protect
Thermal
Cli p
Signal
Powerflex
Power
6250
19"
Page 15
Operating Manual - Powerflex Multi-Channel Power Amplifier
13. SPECIFICATIONS
*Power Output
(Maximum Average Power, 0.1% THD, 1KHz)
Rated Per Channel, Two Channels Driven
Powerflex 6250 Powerflex 4400
4 ohm: 250 Wa tts RMS 400 Wa tts RMS
8 ohm: 150 Wa tts RMS 275 Wa tts RMS
25V (6250 only) 150 W atts RMS *
Mono Bridged (1 Channel)
8 ohm: 500 Watts RMS 800Watts RMS
70V (6250 only) 500 W atts RMS *
Rated Per Channel, All Channels Driven
Powerflex 6250 Powerflex 4400
4 ohm: 250 Watts RMS† 400 Watts RMS†
8 ohm: 150 Wa tts RMS 275 Watts RMS
25V (6250 only) 150 W atts RMS *
Mono Bridged (3 channels)
8 ohm: 500 Watts RMS 800Watts RMS
70V (6250 only) 500 W atts RMS *
Input Impedance: 10K ohm balanced, 37K ohm unbalanced
Typical Idle Current
Powerflex 6250 Powerflex 4400
120V: 0.81A 120V: 0.9A
240V: 0.42A 240V: 0.5A
Current with Typical A udio Program Material (4 ohm load
- all Channels)
Powerflex 6250 Powerflex 4400
120V: 6.5A 120V: 7.0A
240V: 3.3A 240V: 3.5A
Connections
Input: XLR - 1/4” (Pin 2: Hot, Tip: Hot), Euroblock
Output: 5-Way Binding Post
Cooling: Forced Air , Thermal Sensitiv e 3-Speed F an, Front
Inlet/Rear Outlet
Dimensions: 19”L x 5.25”H x 16.5”D
Construction: All-Steel Chassis, Extruded Aluminum Front
Panel
Weight: 45lbs
Specification conditions: 120VAC mains at 60Hz, 25° C
High Pass Filter: 50Hz, 12dB/octave
**Total Harmonic Distortion (20Hz - 20KHz @ 8 ohms):
<0.2%
**IMD
(SMPTE 60Hz/7KHz 4:1)
@ 8 ohms: <0.2% (throughout power range)
(IHF) @ 8 ohms: <0.1% (throughout power range)
**Hum and Noise: -100dB from full output (A-weighted)
Full Power Input Sensitivity:
Powerflex 6250 Powerflex 4400
1.05V RMS (2.6dBu) 1.25V RMS (4.15dBu)
Frequency Response:
8 ohm: ±0.5dB 20Hz-20kHz
4 ohm: ±1.5dB 20Hz-20kHz
Voltage Gain: 32X (30.1dB)
Crosstalk: < -80dB (20Hz - 1KHz)
Signal Present Signal Sensitivity: 13mV RMS (-35.5dBu)
Power Requirement: 110-125VAC, 220 - 250VAC
50/60Hz
* Continuous power limited by power line capacity
**Non-conventional amplifiers require bandwidth limiting
for all distortion and noise measurements.
† Signal peaks in audio programming may trigger protection circuitry at low line voltages. Specifications are subject to
change or improvement without notice.
14. WARRANTY INFORMATION
We thank you for your expression of confidence
in Ashly products. The unit you have just purchased is
protected by a limited five year warranty. To establish the
warranty, you must first complete and mail the warranty
card attached to your product.
Fill out the information below for your records.
Serial Number _________________________________
Dealer ______________________________________
Date of Purchase _______________________________
Dealer’s Address _______________________________
______________________________________
Dealer’s Phone ________________________________
Salesperson ___________________________________
15
Page 16
Operating Manual - Powerflex Multi-Channel Power Amplifier
Printed in USA 10/01
ASHLY AUDIO INC. 847 Holt Road Webster, NY 14580-9103
Phone: (716) 872-0010 Fax: (716) 872-0739
Toll Free (800) 828-6308
www.ashly.com
2001 by Ashly Audio Corporation. All rights reserved worldwide.
6250-3
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