RDL RU-SH1 Installation Guide

RACK-UP® SERIES

Model RU-SH1

Stereophonic Headphone Amp

ANYWHERE YOU NEED...

 A Rack-Mounted Headphone Amplifier
 A Wall-Mounted Headphone Amplifier
 Integral Long-Life VCA Stereo Level Control
 Balanced or Unbalanced Inputs
 Switch-Selectable Input Sensitivity
 Switch-Selectable Mono (L) or Stereo Operation
 To Drive High or Low Impedance Headsets

You Need The RU-SH1!

The RU-SH1 is part of the group of versatile RACK-UP products from Radio Design Labs. These
modules combine advanced circuitry, durable all-metal construction and versatile mounting possibilities.
The compact design permits high-density installations, with three products mounted in a single rack unit!
Optional brackets permit mounting a RACK-UP module above, below, or in front of any flat surface.
Optional rack-mount adapters (RU-RA3) are available for RACK-UP series installation.

APPLICATION: The RU-SH1 is used in applications requiring headphones of any impedance to be
driven from consumer or professional audio sources. The module mounts in RACK-UP series rack
mounts or in various RDL mounting accessories. The RU-SH1 is ideally suited to applications as diverse
as language translation, museums, interview studios and music stores.

The RU-SH1 is a dual channel headphone amplifier with balanced/unbalanced left (INPUT L) and right
(INPUT R) inputs. Each input accepts operating levels between -20 dBV and +20 dBu. Two recessed
slide switches located on the side of the rear enclosure are set prior to mounting the module. One switch
is provided for setting the INPUT SENSITIVITY. The MODE switch selects between stereo and mono
operation. In the MONO (L) position, the left input is used to drive both output channels. When the
module is used in a monaural system, only the left channel input must be wired. The front panel level
control is a long-life potentiometer controlling matched VCAs. Audio does not pass through this control,
assuring years of noise-free level adjustment. The output amplifiers deliver more than 50 mW into either
high or low impedance headphones through a durable, metal ¼” (6.3 mm) standard headphone jack.

Module operation is from a 24 Vdc ground-referenced power supply. It can also operate from a 12 Vdc
supply with a 6 dB reduction in headroom and a maximum output power of 10 mW.

The versatile input level range, low distortion, audio clarity and excellent crosstalk performance make this
module ideally suited to a wide variety of audio applications. Use this module in conjunction with other
RDL modules as part of a high quality, flexible audio/video system.

RDL  659 N. 6th St.  Prescott, AZ., USA 86301  [phone]  FAX [phone]  www.rdlnet.com

RACK-UP® SERIES

Model RU-SH1
Stereophonic Headphone Amp

AUDIO AND POWER WIRING

SIGNAL

FROM

BALANCED

LINE-LEVEL

SOURCE

POWER

SIGNAL

FROM

UNBALANCED

LINE-LEVEL

SOURCE

RDL PS-24

TYPE

SUPPLY

24 Vdc

LEFT

RIGHT

LEFT

RIGHT

I

L

N

STEREO

P
U
T

INPUT SENSITIVITY

R

S

24

V
D
C

I

L

N
P
U
T

INPUT SENSITIVITY

R

S

MODE

MONO (L)

LO

HI

RDL RU-SH1

STEREO HEADPHONE AMPLFIER

MODE

MONO (L)STEREO

LO

HI

Installation/Operation

EN55103-1 E1-E5; EN55103-2 E1-E4

Typical Performance reflects product at publication time
exclusive of EMC data, if any, supplied with product.
Specifications are subject to change without notice.

LOW SENSITIVITY

FOR NORMAL INPUT LEVELS

(TYPICALLY BALANCED)

HIGH SENSITIVITY

FOR LOW LEVEL INPUTS

(TYPICALLY UNBALANCED)

MONO SOURCE
CONNECTED TO

LEFT AUDIO INPUT

STEREO

AUDIO

SOURCE

RDL PS-24

TYPE

SUPPLY

24 Vdc

POWER

NOTE: FOR MONO AUDIO SOURCES, ONLY

CONNECT INPUT TO LEFT (L) INPUT

24

V
D

RDL RU-SH1

C

STEREO HEADPHONE AMPLFIER

TYPICAL PERFORMANCE

Inputs (2): 10 k balanced or unbalanced bridging
Input Level: +4 dBu nominal (Low input sensitivity);

-15 dBV nominal (High input sensitivity)

Maximum Input Level: +21 dBu (Low input sensitivity);

+3 dBu (High input sensitivity)
Output Signal (normal rated): 10 mW into 100 
Output Signal (maximum): 50 mW into 100 
THD+N: < 0.5% @ 1 kHz
Frequency Response: 30 Hz to 20 kHz (+/- 2 dB)
Noise: < -70 dB below normal operating level
Gain: User-adjustable on front panel;

18.5 dB (maximum, High input sensitivity);

Unity (maximum, Low input sensitivity)
CMRR: > 60 dB (50 to 120 Hz)
Crosstalk: Below noise floor (20 Hz to 20 kHz)
Power Requirement: 24 to 33 Vdc @ 50 mA, Ground referenced

SETTINGS

891-3210

Radio Design Labs Technical Support Centers

U.S.A. [phone], [phone]; Fax: [phone]

Europe [NH Amsterdam] (++31) 20-6238 983; Fax: (++31) 20-6225-287