Radial Engineering Twin-Servo User Manual

RADIAL 500 SERIES

+10

dBu

smart sheet

Order No. R700 0111 10

TWIN-SERVO™ MICROPHONE PREAMPLIFIER

The Jensen Twin-Servo™ utilizes Deane Jensen’s iconic 990 op-amp design to deliver the
most exceptional mic preamp built in the 500 series format. The circuitry boasts two 100%
discrete 990 op-amps cascaded in tandem to deliver 60dB of gain, with incredibly low noise
and phase distortion, and an ultra-wide 0.2Hz-150kHz frequency response. Jensen input
and output transformers provide massive amounts of headroom, with clean and transparent
operation suitable for the most critical recording applications. A 21-detent gain control makes
for easy session recalls, with a 10-segment LED meter for accurate signal management. 48V
phantom power, a 180° polarity reverse, high-pass fi lter and -15dB pad are also provided,
all with individual LED indicators to verify settings at a glance. When it comes to high
performance mic preamps, nothing beats the Jensen Twin-Servo.

OMNIPORT - When used with a Radial Workhorse power rack
the omniport is assigned as a unbalanced 220K ohm instrument
input.

FEATURES

• Ultra-low noise preamp with over 60dB of gain

• Built in high-pass fi lter and 180° polarity reverse

• Dual Jensen transformers for maximum head-

room

APPLICATIONS

• Perfect for recording any source

• Transparent and detailed operation

• Amazing low end reach and wide bandwidth

COOL FACTORS

• Combo input to record mics or instruments

• LED indicators to determine settings at a glance

• 21-position gain control allows for accurate ses­sion recalls

FREQUENCY RESPONSE

+8

+6

+4

+2

0

-2

-4

-6

-8

-10
10

20

200

2k

Hz

20k

100k

50k

10 SEGMENT METER - Custom designed circuit for greater VU
meter accuracy.

DUAL-GANG POT - Simultaneously controls the dual 990 op­amp topology for optimal gain at all levels.

180° - Inverts pins 2 and 3 at the output to help phase align
microphones when two channels are in stereo use.

HPF - Gentle high-pass fi lter may be inserted into the signal
path to reduce excessive low frequency content and control
resonance.

PAD - Reduces the input sensitivity by -15dB when amplifying
exceedingly high output sources.

48V - Activates the 48V phantom power supply for use with
condenser microphones and active direct boxes.

COMBO - Combination balanced XLR mic input and 1/4”
instrument input is mounted on front panel for ease of use.

FULL ENCLOSURE - 100% encased steel casing reduces
magnetic interference from nearby modules that may cause
noise pollution.

GROUND LIFT – Set and forget rear panel
ground switch lifts the pin-1 ground at the
XLR input.

JENSEN OUTPUT TRANSFORMER – The
JT-11-EM is linear from 2Hz-200kHz with
less than 0.001% distortion at 20Hz.

JENSEN MIC INPUT TRANSFORMER
– The JT-16-PCJR is exceptionally quiet,
linear from 5Hz-50kHz with less than 0.06%
distortion at 20Hz.

JENSEN DUAL 990 OP-AMPS – 100%
discrete audio signal path without any tone
shifting capacitors.

Using the Twin-Servo with a
condenser mic

The Jensen Twin-Servo has almost unlimited
bandwidth and tremendous headroom. This
makes it a perfect choice for the most demand­ing recording, particularly when recording highly
dynamic signals such as vocals or orchestral
instruments.

Radial Engineering Ltd. • Workhorse 500 Series Smart Sheet © Copyright 2018 all rights reserved · www.radialeng.com · email [e-mail] • Subject to change without notice • Made in Canada

Using the Twin-Servo with an
active DI

When recording live, capturing the direct feed
from an instrument can provide much more con­sistent results as bleed from other instruments
can be eliminated. Connect a piezo transducer
to the Radial PZ-DI and send this to the Twin­Servo for amazing bottom end!

Using the Twin-Servo with a
ribbon mic

Most modern ribbon microphones have plenty
of output and can connect directly to the Twin­Servo’s low noise circuitry. When using old vin­tage mics, add the Radial McBoost to increase
the output by up to 25dB for a total of about
85dB of gain!