Function, functional components and their effect
The V2359j amp4ribbon microphone preamplifier enables the connection of all passive transducers, such
as ribbon, moving coil, carbon, piezo and crystal microphones. With a continuously adjustable
preamplification in the range of 26 dB to 59 dB (optionally up to 76 dB, see bulletin no. 005 on our
homepage at https://www.rogerschult.com/downloads.php) the microphone signal is raised to the
required line level.
A gain reduction of -15 dB (optionally -20dB) can be activated by a switch (pad -15 dB).
This is followed by the adaptation of the load impedance by the impedance controller (Z) in order to
determine the frequency response and thus the character of the sound transducer. This unique continous
impedance matching in the range from 150 ohms to 22 kOhms is a powerful tool for determination of the
transfer function. Whether linearly optimized or to create a sound full of character, this controller can be
used in versatile ways.
The V2359j amp4ribbon has three different filters to change the frequency. To eliminate low-frequency
interference or to reduce the bass, a high pass (LF, fader below right) is activated with a reduction of up to
-17 dB at 20 Hz. A Baxandall filter (HF, fader top right) with +/- 12 dB at 9 kHz for high frequencies and a
semi-parametric filter for the mid frequencies. With this mids filter (MF), the frequency can be
continuously adjusted between 150 Hz to 3.5 kHz and the level range from +/- 10 dB. The choice of the
filter quality (Q) can be preselected by means of a three position toggle switch with left stop 0.4 (wide),
center position 0.7 (narrow) and right stop variable by means of a trim potentiometer (trim Q, preset to 3
at factory) between 2.4 and 4. The entire filter unit can be deactivated using the (bypass filter) switch.
(+48 V) phantom power supply is an extension for the use of active microphones. When the phantom
power pressure switch is activated, the impedance is fixed to a value of 2 kOhm to protect the microphone
electronics.
Functional components
V
(gain) rotary control gain adjustment from 26 dB to 59 dB
Pad
(attenuation) switch, gain reduction of -15 dB (optional -20 dB)
Z
(impedance) rotary control, adjustment of load impedance from 150 ohms to 22 kOhms
LF
(high pass) fader, low frequency filter down to -17 dB at 20 Hz
HF
(Baxandall filter) fader, high frequency filter, range +/- 12 dB at 9 kHz
MF
(PEQ) 2 rotary co trimmer for the mids as a semi-parametric EQ
Potentiometers for frequencies from 150 Hz to 3.5 kHz and level with +/- 10 dB
Toggle switch for quality (Q factor) 0.4 and 0.7 and
Trimmer for fine adjustment of the quality in the range from 2.4 to 4
+ 48V
(phantom power) pressure switch to activate the +48 V
Note: all pressure switches are illuminated when activated
-4 -
