Frequency Response:; Phase Response:; Damping Factor:- Page 47

RECORDING & BROADCAST

T

he D-45 and D-75A are long-term standards. They are perfect for moderate power applications 

such  as  recording  or  broadcast  studio  near-field  monitoring,  video  suite  audio  monitoring,  a 

recording/broadcast headphone amp or a small paging system. Convection cooled, the highly reli-

able D Series is protected against shorted, open, mismatched or low-impedance loads.



SPECIFICATIONS

Performance

Frequency Response:

 ±0.1 dB from 20 Hz to 

20 kHz at 1watt.

Phase Response:

 +10 to –15 degrees from 

20 Hz to 20 kHz at 1 watt.

Signal-to-Noise:

 106 dB from 20 Hz to 20 

kHz at full bandwidth FTC power.

Total Harmonic Distortion (THD):

 Less 

than 0.001% at full bandwidth FTC power 

from 20 Hz to 400 Hz increasing linearly to 

0.05% at 20 kHz.

Intermodulation Distortion (IMD):

 (60 Hz 

and 7 kHz 4:1) Less than 0.01% from 0.25 

watts to full bandwidth FTC power, and less 

than 0.05% from 0.01 to 0.25 watts.

Crosstalk:

 Greater than 100 dB below full 

bandwidth FTC power from 100 Hz to 1 kHz 

decreasing linearly to 80 dB at 20 kHz.

Damping Factor:

 Greater than 400 from DC 

to 400 Hz.

Controlled Slew Rate:

 6 volts per ms. (Slew 

rates are limited to useful levels for ultra-

sonic/RF protection.)

Voltage Gain:

At the maximum level setting, 8-ohm load, 

0.775V input sensititivity.

D-45:

 18.3:1 ±3% or 25.2 dB ±0.3 dB.

D-75A:

 23:1 ±3% or 27.3 dB ±0.3 dB.

Load Impedance:

 Safe with all types of loads. 

Rated for 4 to 16 ohms in dual mode, and 8 

to 16 ohms in bridge-mono mode.

AC Line Voltage and Frequency Configura-

tions Available:

 100, 120, 220 and 240VAC 

(±10%), 50 to 400 Hz for international units 

(depending on the transformer configuration). 

North American 120VAC, 60 Hz units are not 

convertible and can only be used at the speci-

fied voltage and frequency. All units draw 15 

watts or less when idle. Maximum AC power 

consumption is 150 watts.

Controls

Power:

 A two-position front panel rotary 

on/off switch.

Level:

 An independent 31-position detented 

front panel level control for each channel.

Dual/Mono:

 The dual/mono jumper is 

located inside the amplifier.

Ground Lift:

 To prevent ground loops, the 

chassis and signal grounds are separated 

(or “lifted”) by a permanent impedance 

installed between them. There is no control 

for this feature.

Indicators

Signal Presence:

 The green front panel 

indicator for each channel flashes synchro-

nously with the channel’s output signal to 

indicate its presence.

Input/Output Comparator:

 The red Input/

Output Comparator (IOC) indicator for each 

channel flashes if any type of distortion 

reaches 0.05%.

Input/Output

Input Connector:

 A balanced 3-pin female 

Neutrik® combination XLR and ¼-inch 

(6.35-mm) phone connector for each chan-

nel.

Input Impedance:

 Nominally 20 k ohms, bal-

anced. Nominally 10 k ohms, unbalanced.

Input Sensitivity:

 Configurable for 26 dB gain 

or 0.775 volt sensitivity.

Output Connector:

 Barrier block terminals 

and stereo headphone jack. The headphone 

output is unpadded, and in parallel with the 

main amplifier outputs.

Output Impedance:

 Less than 15 milliohms in 

series with less than 3 microhenries.

DC Output Offset:

 10 millivolts or less.

Output Signal

Dual: 

Unbalanced, two channel.

Bridge-Mono:

 Balanced, single channel. 

Channel 1 controls are active; channel 2 

controls should be turned down.

Protection

Input:

 The inputs have series resistance that 

provides input overload protection. Controlled 

slew rate voltage amplifiers protect against 

radio frequencies. The AC line is fused to 

protect against excessive current draw.

Output:

 Instantaneous limiting protection for 

short circuits, open circuits and mismatched 

loads.

Turn-On:

 Minimum thumps. Power-up is 

instantaneous with no program delay.

Construction

Durable black finish on aluminum front panel 

with gray suede Lexan insert. Aluminum 

chassis provides maximum heat conduction 

and minimum weight.

Dimensions:

 19-inch (48.3 cm) rack mount 

width, 1.75 inches (4.5 cm) high, 8.5 inches 

(21.6 cm) deep behind the mounting surface, 

and a 0.625-inch (1.6-cm) protrusion in front 

of the mounting surface.

Net Weight:

D-45:

 8 lb, 11 oz (3.9 kg) 

D-75A:

 9 lb, 7 oz (4.3 kg).

Shipping Weight:

D-45:

 10 lb, 9 oz (4.8 kg) 

D-75A:

 11 lb, 4 oz (5.1 kg).

Cooling:

 The amplifier is totally convection 

cooled. The entire aluminum chassis acts as 

a conductor to dissipate heat. The covers and 

front panel extrusion also act as heat sinks. 

Much of the unit’s heat is conducted through 

the extruded front panel. This design is used 

so that front panel contact with the equipment 

rack will also dissipate heat.

Regulatory Certifications

Other Applications

8/06                                                          136711-1C