The Headphone Amplifier Box Performance Specifications

Frequency Response
+/-0.5 dB from 20 Hz to 20 kHz; - 3 dB 50 kHz

Noise
Less than -60 dBu (Note 1)

Distortion
Less than 0.1% from 20 Hz to 20 kHz

Gain Range
MIC
+26 dB to +60 dB
LINE1
-4 dB to +30dB
LINE2
-24 dB to +10 dB

Common Mode Rejection
Greater than 80 dB

Input Common Mode Clipping
Greater than 0 dB

Input Impedance
MIC
5 kOhms
LINE1
120 kOhms bridging
LINE2
Balanced 120 kOhms; unbalanced 60 kOhms bridging

Input Clipping Level
MIC
-10 dB
LINE1
+18 dBu
LINE2
+38 dBu

Output Impedance
Less than 50 Ohms for 32 Ohm to 1 KOhm headphones

Output DC offset
Less than 50 mVolts

Output Clipping Level
+15 dBu

Connectors
Input
XLR three pin female or 0.25 inch three pole A gauge jack combination socket
Output(Loop Through)
XLR three pin male
Headphone Output
0.25 inch three pole A gauge jack socket

Pin Connections
Signal Input and Output
PIN 1 (sleeve) GROUND; PIN 2 (tip) SIGNAL; PIN 3 (ring) RETURN
To unbalance connect PIN 3 to ground
Headphone Output
SLEEVE: COMMON; RING and TIP: SIGNAL

PP3 Alkaline Battery Life
50 Hours typical

External DC Connector
2.5 mm centre pin positive (Note 2)

Dimensions
Width 80mm; Height 45mm; Depth 135mm

Weight
300 gm including battery

Notes to specifications

  1. Measurements of dBu are dB with respect to 0.775 volts
  2. The unit may be operated from an external supply between 6 and 12 volts DC (maximum) at 15 mA quiescent, 100 mA peak. The recommended voltage is 9 volts. The supply should be floating and regulated
  3. A fitted belt clip is available to special order

Operating Controls

Front Panel
Sensitivity Selector
Three position slide switch
Connectors
Audio input and loop through output; Headphone output

Rear Panel
Battery Holder
PP3 externally accessible
Power on/off
Two position slide switch with LED indicator
Connector
External DC supply
Top Panel
Level
Rotary Potentiometer

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Conford Electronics Conford Liphook Hampshire GU30 7QW England
Telephone +44 (0)1428 751469 Fax 751223 E-Mail contact@confordelec.co.uk