207d
instruction Manual
Aphex Systems Ltd. Model 207D
Page 4
207d
2-ch tube mic preamp with adc
Page 5
Aphex Systems Ltd. Model 207D
OPERATING LEVEL
This adapts the model 207D’s internal dynamic
range to match either professional balanced equip-
ment or semi-professional unbalanced equipment at
the output. It controls both output jacks. Both jacks
supply the same output level. Set as needed.
DIGITAL AUDIO
In external sync mode, the 207D locks up to frequen-
cies between 32 and 96kHz. The push button located
in the meter window toggles the operating mode
among the internal frequency modes and external
sync. The AES3 and S/PDIF outputs will properly inter-
face with all standard inputs. Follow the procedures
recommended in this manual for proper installation
and use.
Quick Setup
Standard Hookup to Rear Panel
ONE CHANNEL SHOWN
*Why You Shouldn’t Connect a 207D’s Output to a Mic Level Input.
The bottom line: you will get a lot of noise and possibly a
lot of distortion. The Model 207 is designed to generate a line level output from a mic level input. It optimizes the signal to noise ratio by
giving you a strong signal far above the preamplifier’s basic self noise level. This strong output signal can be up to 65dB higher than the
mic signal. It is perfect in level for a standard line input of a mixer or console. However, it will overload a mic input. If you turn down the
207’s gain to reduce its output low enough to stop overloading the mic input of your mixer, then your large console gain amplifies the
basic noise floor of the 207. That will result in a very poor signal to noise ratio. Always use the most gain possible in the 207 and adjust
your mixer’s fader or line input gain to accept it, and never feed a mic input from a 207D.
MicLim™
Switches on the
MicLim operating
mode. Use is always
recommended.
Switch off mainly for
testing.
LIMITING LED
Shows when MicLim is
working.
OUTPUT TRIM
Screwdriver adjustable, works
with the rear panel OPERATING
LEVEL switch to calibrate the
207’s output level to precisely
match external equipment.
GAIN
Adjusts the microphone pre-
amplifier and instrument gain.
INSTRUMENT INPUT JACK
Input impedance is 1 megohm to
properly accept 99% of all music
instrument pickups. It is not designed
to receive extremely high impedance
non powered piezo pickups, how-
ever.
OUTPUT HEADROOM METER
Indicates the available headroom in decibels
below clipping. At 0dB the output level reaches
the maximum level available at all outputs
depending upon the Output Trim and Operat-
ing Level settings.
MIC INPUT
DO NOT feed
mic inputs
OUTPUTS
INSERT
CHANNEL 1
-10 +4
Pin1 = Sleeve = GND, Pin 2 = Tip = HI, Pin 3 = Ring = LO
OPERATING
LEVEL
S Y S T E M S
AES3 OUT
SPDIF
CLOCK IN
MODEL 207D 2 CHANNEL MIC PRE 24/96
IN
OUT
“Y” CABLE
See Apdx D
Use balanced or unbalanced cables as
needed. Consult Appendix D for wiring
options.
To Inputs of
Line Level Devices.
DO NOT Connect to Mic
Level Inputs!*
T
Select the correct OPER-
ATING LEVEL to most
closely match your
receiving equipment’s
input sensitivity.
Mic Source
Passive or
Phantom Powered
Use high quality balanced mic cables.
Line Level
Processor,
i.e.,
Compressor, EQ
Digital Audio Interface
AES3 and S/PDIF
External
Word Clock
Input