VTBP-201S Tube Bass Preamplifier User’s Guide
The classic VTBP-201 by James Demeter is now reborn in this new single space rack chassis. All of
the sound and controls of the classic have been retained and some new features have been added. The
VTBP-201S bass preamplifier continues the sonic excellence of its predecessor. It features a high volt
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age (270V fully regulated), all tube design providing all of the tube preamplifier gain and output drivers,
classic passive tone controls, and a balanced microphone level Jensen transformer output for recording
or house PA. Two unbalanced line level outputs for amplifier connections and a mute switch. As with all
Demeter equipment, it is meticulously hand wired using the finest components and assembled in the
U.S.A.
CONTROLS AND FEATURES
INPUTS
Passive: For passive basses or basses with lower output.
Active: Provided for basses with internal preamplifiers or basses with a very high output. If both inputs
are used, there is a circuit that mixes the inputs.
TUBE PREAMPLIFIER
Bright Switch: this boosts the high frequency at 6 dB per octave from 1 kHz. The total gain of the bright
switch is dependent on the volume control setting (i.e. the lower the volume the greater the effect of the
bright switch).
Volume: this controls the output level of all outputs except the effects loop and tuner.
Treble: a passive 6 dB per octave, shelving and high frequency control. Boost or cut of 10dB. This con
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trol effects the 4 k to 20 k range.
Middle: a passive 6 dB per octave peaking mid frequency control. Boost or cut of 10 dB. This control is
centered at 600 Hz.
Bass: a passive 6 dB per octave, shelving, low frequency control. Boost or cut of 10 dB. This control ef
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fects the 120 Hz to 10 Hz range or the 240 to 20 Hz range depending on the EQ switch’s setting.
Presence: an active 6 dB per octave, shelving upper-mid to high frequency control. Boost in the 2 to 20
k range. The flat setting for this control is the knob turned all the way to the left.
Bass EQ Switch: selects between the peak frequencies of 60 Hz and 120 Hz for the bass control.
Presence Frequency Switch: selects between the peak frequency of 2 kHz and 4 kHz for the presence
control.
EFFECTS LOOP
Effects Loop Switch: this switch engages the effects loop section of the preamplifier activating the back
and the controls in front. With nothing inserted in this jack, the switch will kill the signal.
Send Control: controls the level leaving the send jack of the preamplifier (the input jack of your effect).
Return Control: controls the level returning to the preamplifier from your effects unit into the bass pre
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amplifier.
Mute Switch: mutes all outputs except the flat setting on the Jensen balanced output and tuner output.
6990 Kingsbury Road | Templeton, CA 93465 | 805-461-4100 | http://www.demeteramps.com/
