Peterson AutoStrobe 490ST - Manual (Page 7)

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7 6 5 4 3 2 1 0 0 1 2 3 4 5 6 7
KEY=C
A=440 C 00
4
AUTO
SETUP MODE MET
1 2 3 4
B A G F E D C
A# G# F# D# C#
ENTER
KEY
+2
--
-1
DISPLAY
EXTERNAL
INPUT THRU
POWER
peterson
= <
MUTE
S r e t t
c
h
490-ST Tuner
AutoStrobe TM
1 2
7 10
3
5
6
11
8
4 9
THE AutoStrobe 490-ST—IN DEPTH
1. SUMMARY OF FEATURES AND FRONT PANEL CONTROLS
We will begin with a brief description of the front panel controls, indicators, and basic features of the Model 490-ST. This
will provide you with a quick reference guide to the front panel of the tuner. Detailed information about each feature is
explained in the succeeding sections of this manual.
FRONT PANEL
1. STABLE, ACCURATE, DIGITALLY-CONTROLLED STROBE — The back-illuminated, eight-octave band strobe
disc is spun by a digitally-controlled motor. The rotation speeds are derived from a quartz crystal reference for the
ultimate in accuracy and stability. Hence, no warm-up period is required, and the instrument will maintain its 1/10 of
1 cent

accuracy with no need for re-calibration…EVER! The International Standard Pitch of A=440 Hz (cycles per
second) is the factory default but can be raised or lowered in 1 Hz increments from A = 350 Hz to A = 550 Hz. The
Model 490-ST can be customized to power-up with an altered Concert A pitch as one of the storable SETUP parameters
available to the user. The unparalleled accuracy of this system also allows the Model 490-ST to reliably distinguish the
nuances of multiple temperaments

and stretches

, both standard and customizable, beyond the conventional equal-
tempered scale.
2. POWER SWITCH — The down or OFF position disengages the line voltage; the up or ON position permits the unit
to power up.
3. SELF-CONTAINED MICROPHONE & EXTERNAL PATCH THROUGH INPUT — The Model 490-ST is
equipped with a built-in condenser microphone for simple use with acoustic inputs. The intonation of notes sounded
into this microphone will be immediately visible on the strobe tuning disc when automatic note detection is enabled
(which is the factory-default power-up condition). Immediately to the right of the internal microphone is a 1/4" jack
for an external input such as an external microphone, guitar-type pick-up, or any low or line-level audio signal in
electrical form. (An appropriate external microphone is available from peterson as part #: 170172.) The internal
microphone is automatically disconnected whenever a 1/4" connector is inserted into this “EXTERNAL INPUT” jack.
To the right of the “EXTERNAL INPUT” jack is a 1/4" THRU jack. This passively conducts the input signal—internal
mic or external input, whichever is currently active—back out to additional audio devices allowing the 490-ST tuner
to be permanently placed within your “audio chain” for your convenience.