LaChapell Audio 583E User Manual - 583E Controls
LACHAPELL AUDIO 583E
5
583E CONTROLS
CONTROL DETAILS
• TUBE DRIVE / INPUT GAIN: The INPUT controls how much of the source signal is fed to the first stage
of the vaccuum tube. Higher levels will drive the tube harder and result in more harmonics. Think
of this control as your anount of tube coloration/harmonics (distortion).
• OUTPUT GAIN: Provides variable control over line level signal strength. Think of this control as your
source for clean gain. Typically, this control is used to establish the desired line level after the input
gain has been set but it can work interactively with the INPUT for a wide array of tonal possibilites.
• INPUT SELECT: Alternates between rear panel microphone XLR input or front panel ¼ Hi-Z input.
Each position defeats the other.
• HI-Z INPUT: The Hi-Z input stage is transformerless and operates with an input impendence of
100Kohm. It cannot make use of the -20dB pad.
• 48V (Phantom): This toggle provides a 48 volt supply of
DC current for all condenser microphones.
• 20dB INPUT PAD (-20): When engaged, the microphone
input source signal is reduced by 20dB.
• POLARITY REVERSE: Reverses the polarity of the output
line level signal.
Model 583e: Vacuum Tube Preamplifier with EQ
Hi-Z
OUTPUT
LaChapell Audio
Off
On
0
-20dB
Max
Min
+8
-8
+8
-8
+8
-8
400
160
30
5k
1.8k
325
20k
10k
2.5k
INPUT
Max
Min
Nrm
0
Independent EQ
Pre+EQ
Mic
Input
Polarity
Pad
48v
Hi-Z
Low
Mid
High
PHANTOM
POWER
-20 dB
INPUT PAD
POLARITY
REVERSE
INPUT
SELECT
HI-Z
INPUT
EQ ASSIGNMENT
SELECT
HIGH BAND
FREQ.
HIGH BAND
CUT & BOOST
MID BAND
FREQ.
MID BAND
CUT & BOOST
LOW BAND
FREQ.
LOW BAND
CUT & BOOST
TUBE DRIVE
INPUT GAIN
OUTPUT
GAIN
CREATIVE TIP:
For near transformer-less sound,
consider engaging this pad function
and compensate for the loss of gain
by increasing the input gain control.
This approach effectively minimizes
the gain coming from the Jensen
input transformer while drastically
increasing the character of the
vacuum tube (this is only possible
with the microphone path).