Specifications For The Dm38 - Halcro DM38 Owner's Manual

dm38

Specifications for the dm38

POWER
Power output into 4ohms resistive > 350W
Power output into 8ohms resistive > 180W
DISTORTION (Footnote 1).
At full power output, all harmonic distortion orders
THD <-110dB (<3000 parts per billion) up to 20kHz
(100kHz B.W.) at 350W into 4 ohms.
THD @ 1kHz <-130dB (<300 parts per billion).
For sum of 19 and 20kHz tones, each delivering 100W
into 4 ohms = peak power 350W, intermodulation
products each <-110dB relative to output.
SMPTE-IM intermodulation products each
<-110dB relative to output.
INPUTS
There are 3 input modes:
An unbalanced voltage mode input with an
impedance of 10kohm
A balanced voltage mode input with an impedance
of 10kohms + 10kohms
A current-mode input with a 60ohm input
impedance to minimize cable reflections (to be fed
from an infinite impedance current source)
Voltage gain of the balanced and unbalanced
inputs is 30V/V
The gain of the current mode is 5V/mA
NOISE
The equivalent input noise at the input is 5nV/sqrt(Hz)
for the voltage modes and 6pA/sqrt(Hz) for the current
mode.
SLEW RATE LIMIT:
POWER SUPPLY (Footnote 2).
Active power factor correction minimizes mains
current harmonic distortion
110V model operates from 100-120V RMS, 45-
65Hz,
240V model operates from 220-240V RMS, 45-65Hz.
Less than 100 parts per million mains hum and
ripple on the amplifier power rails
Conforms with all current emission and safety
standards
OVERLOAD (Footnote 3).
Recovery from hard overload at 20kHz into 4ohms:
1 s.
DIMENSIONS
Height, 31 inches or 79 cm
Width, 16 inches or 40 cm
Depth, 16 inches or 40 cm
Weight, 120 lbs. or 55 kg
Shipping weight, 187 lbs. or 85 kg
100V/ s
PROTECTION
THE AMPLIFIER PROTECTION:
Is short-circuit proof
Has over current limiting
Will cut out if temperature is excessive
Will cut out if a continuous D.C. offset
appears on output
Will cut out if output current exceeds 10A
average continuously over a period of a few
minutes
Is protected against most input overloads
THE POWER SUPPLY PROTECTION:
Will cut out if most common faults are
detected in the power supply (e.g. over-
voltage, master clock at incorrect frequency,
excessive temperatures etc)
Is protected against most mains transients
COMPONENTS (Footnote 4).
All semiconductors are at least industrial
grade in both the power supply and amplifier,
for reliability
All electrolytic capacitors are exceptionally
long life industrial grade in both the amplifier
and power supply
Only highly linear resistors and the lowest
impedance polypropylene capacitors are
employed in the critical audio path
6-layer PCBs are used in the power amplifier
to minimize stray magnetic fields and to
accurately define voltages
4-layer PCBs are used in the power supply to
minimize E.M.I. and voltage transients, which
improves reliability and power efficiency
COMPARTMENTS
There are 3 heavily shielded compartments:
Power supply unit
Input amplifier section
Power amplifier compartment
FILTERING
Series and common mode EMI filtering is present
on the mains input
between the amplifier and power supply
High frequency filtering is present at the inputs and
output.
FOOTNOTES
1. THD specifications of our typical best competitors are,
200,000 parts per billion.
2. Unique to the best of our knowledge.
3. Indicates no excessive negative feedback.
4.
"Industrial" grade is a higher grade than the "commercial"
grade used by most manufacturers.
TM
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