VT 4000/2
VT 4000/2 TWIN-CASCODE FULL SYMMETRICAL DISCRETE-TUBE CLASS QUAD-PREAMPLIFIER
Recent progresses in the recording technology and digital editing, with newer computerized workstations, have made it possible to obtain a sound quality which was unthinkable before, together with an endless editing power. All this at more and more accessible prices. In this age of high-resolution, the microphone pre-amplifier sonic characteristics crucially determine the final quality of digital recording. Current systems, based on workstations, capture subtleness that were before lost in the noise of the tape or covered by an irregular response in frequencies. Early complaints concerning the “coldness of the digital sound” came up, but those effects are usually caused by microphone pre-amps of inferior quality, whose imperfections that can only be heard now with the precision of the digital recording.
Furthermore, many users that demand the power and the flexibility of the new digital technologies yearn for the warmth and for the acoustics of the analogical circuit and very often want to get the coveted acoustic vintages. Attending to this new reality, HotSound has developed the VT 4000/2, a microphone/instrument high-quality four channel pre-amp, operating within the pure ‘A’ class and using low noise valves and transistors, in totally discreet circuits.
CHARACTERISTICS
This equipment is composed by two microphones, electrical instrument or line pre-amplifiers, with variable slew-rate (SPEED), adjustable progressive saturation of mild characteristic (HARMONICS DRIVE) and an inedited high frequencies enhancer (BREATH). Also, both channels have gain control of 60dB, extreme wide frequency response and a passive high-pass filter.
The microphone input has low impedance (1200 ohms) and gives a better microphones performance.
VT also has electrical instruments inputs (one per channel) of high impedance which are directly applied to the pre-amplifier circuits through J-FET couplers. These inputs also allow direct recording, not needing other treatments. Moreover, the VT is also a Direct-Box and with an amazing performance for this application!
The microphone inputs can change to a line input with a simple button click (PAD LINE) and can be used with any line level signal source.
Despite of a base technology from the 50s-60s, the VT inner architecture has inedited elements, like the concept and the components used, in all the audio industry. It is based in two cascade gain stages (cascode), the first with transistors and the second with tubes. Plus an out block of high voltage and power developed with transistors. All the blocks are differentials (twin) and operate in pure class A.
The first gain stage add until +40dB and delivers its signal to a passive high-pass filter, adjustable from 10 to 200Hz and with an extreme soft attenuation (-6dB/octave). After this filter, the signal is direct applied to two double-triode 7025 tube grids. This is the second gain stage and contributes with +20dB of gain. This circuit allows slew-rate variation (SPEED control), also controls the saturation through the HARMONIC DRIVE control that is not just a simple quantity control because it also “shapes” the distortion harmonic formation, varying since a soft distortion, which predominates the third harmonic until a deepest, which predominates the second harmonic with just a touch of the third. The SPEED and HARMONIC DRIVE controls allow to create the authentic vintage pres from the 50s-70s, through the tube circuit speed manipulation and by the harmonic distribution. But despite of all this manipulation power, VT is an extreme transparent pre-amplifier, if so wished.
Still in this second stage, it was implemented the BREATH function: a voice optimized enhancer, providing great high harmonics quantities and heat. The traditional phase reverser key (POLARITY) is also available. Check the following blocks diagram picture of VT channel.
Recent progresses in the recording technology and digital editing, with newer computerized workstations, have made it possible to obtain a sound quality which was unthinkable before, together with an endless editing power. All this at more and more accessible prices. In this age of high-resolution, the microphone pre-amplifier sonic characteristics crucially determine the final quality of digital recording. Current systems, based on workstations, capture subtleness that were before lost in the noise of the tape or covered by an irregular response in frequencies. Early complaints concerning the “coldness of the digital sound” came up, but those effects are usually caused by microphone pre-amps of inferior quality, whose imperfections that can only be heard now with the precision of the digital recording.
Furthermore, many users that demand the power and the flexibility of the new digital technologies yearn for the warmth and for the acoustics of the analogical circuit and very often want to get the coveted acoustic vintages. Attending to this new reality, HotSound has developed the VT 4000/2, a microphone/instrument high-quality four channel pre-amp, operating within the pure ‘A’ class and using low noise valves and transistors, in totally discreet circuits.
CHARACTERISTICS
This equipment is composed by two microphones, electrical instrument or line pre-amplifiers, with variable slew-rate (SPEED), adjustable progressive saturation of mild characteristic (HARMONICS DRIVE) and an inedited high frequencies enhancer (BREATH). Also, both channels have gain control of 60dB, extreme wide frequency response and a passive high-pass filter.
The microphone input has low impedance (1200 ohms) and gives a better microphones performance.
VT also has electrical instruments inputs (one per channel) of high impedance which are directly applied to the pre-amplifier circuits through J-FET couplers. These inputs also allow direct recording, not needing other treatments. Moreover, the VT is also a Direct-Box and with an amazing performance for this application!
The microphone inputs can change to a line input with a simple button click (PAD LINE) and can be used with any line level signal source.
Despite of a base technology from the 50s-60s, the VT inner architecture has inedited elements, like the concept and the components used, in all the audio industry. It is based in two cascade gain stages (cascode), the first with transistors and the second with tubes. Plus an out block of high voltage and power developed with transistors. All the blocks are differentials (twin) and operate in pure class A.
The first gain stage add until +40dB and delivers its signal to a passive high-pass filter, adjustable from 10 to 200Hz and with an extreme soft attenuation (-6dB/octave). After this filter, the signal is direct applied to two double-triode 7025 tube grids. This is the second gain stage and contributes with +20dB of gain. This circuit allows slew-rate variation (SPEED control), also controls the saturation through the HARMONIC DRIVE control that is not just a simple quantity control because it also “shapes” the distortion harmonic formation, varying since a soft distortion, which predominates the third harmonic until a deepest, which predominates the second harmonic with just a touch of the third. The SPEED and HARMONIC DRIVE controls allow to create the authentic vintage pres from the 50s-70s, through the tube circuit speed manipulation and by the harmonic distribution. But despite of all this manipulation power, VT is an extreme transparent pre-amplifier, if so wished.
Still in this second stage, it was implemented the BREATH function: a voice optimized enhancer, providing great high harmonics quantities and heat. The traditional phase reverser key (POLARITY) is also available. Check the following blocks diagram picture of VT channel.
The global gain is adjustable from 10 to 60dB and an analogical V.U. Meter with separated peak indication provides the output level. VT is equipped with electro-mechanic analogical V.U. Meters, in the best vintage visual, plus the peak indicators.
The outputs are made of two high voltage amplifiers operating in pure class A. Them are able to deliver until +26dBu (22Vp) with load of 600 ohms, in differential outputs of low impedance and great current capability. The outputs can be attenuated is steps of 10dB, from 0 until -30dB, by a selector key located on the front panel (OUTPUT ATENUATOR).
The outputs are made of two high voltage amplifiers operating in pure class A. Them are able to deliver until +26dBu (22Vp) with load of 600 ohms, in differential outputs of low impedance and great current capability. The outputs can be attenuated is steps of 10dB, from 0 until -30dB, by a selector key located on the front panel (OUTPUT ATENUATOR).
Superior dynamic range at 135dB, compatible with 24-bit digital systems.
MIC EIN (Equivalent Input Noise) of -126dBu (22-22kHzweightless).
Microphone Input Impedance of 1200 ohms, no transformer, PNP bipolar
active, symmetrical-differential discrete class A architecture.
INSTRUMENT Input Impedance of 1 Mega ohm, J-FET.
Two Sovtek 7025 tubes, twin-cascode symmetrical-differential architecture, pure class A.
Continuous gain adjustment, of 10-60dB.
Frequency Response from 14Hz to 100KHz (-3dB).
POLARITY switch (phase reversion).
Passive High Pass Filter of -6dB/octave, continually adjustable from 10-200Hz.
Adjustable SPEED TIME in 4 options.
Adjustable HARMONIC DRIVE in 4 options.
High-harmonic enhancer BREATH switch, optimized for voice;
MIC/INSTR Key selector;
Individual PHANTON POWER channel (48V);
Analogical V.U. meter;
XLR connection Servo-balanced outputs.
MIC EIN (Equivalent Input Noise) of -126dBu (22-22kHzweightless).
Microphone Input Impedance of 1200 ohms, no transformer, PNP bipolar
active, symmetrical-differential discrete class A architecture.
INSTRUMENT Input Impedance of 1 Mega ohm, J-FET.
Two Sovtek 7025 tubes, twin-cascode symmetrical-differential architecture, pure class A.
Continuous gain adjustment, of 10-60dB.
Frequency Response from 14Hz to 100KHz (-3dB).
POLARITY switch (phase reversion).
Passive High Pass Filter of -6dB/octave, continually adjustable from 10-200Hz.
Adjustable SPEED TIME in 4 options.
Adjustable HARMONIC DRIVE in 4 options.
High-harmonic enhancer BREATH switch, optimized for voice;
MIC/INSTR Key selector;
Individual PHANTON POWER channel (48V);
Analogical V.U. meter;
XLR connection Servo-balanced outputs.
RESOURCES (per channel)
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HotSound Indústria e Comércio de Equipamentos Eletrônicos Ltda
Estrada Municipal Governador Mario Covas, nº 641, Condomínio Portal do Anhanguera Rua B nº: 132. Bairro Macuco, Valinhos – SP CEP: 13279-411 Fone/Fax: 55-(19)3869-1478 - falecom@hotsound.com.br
Estrada Municipal Governador Mario Covas, nº 641, Condomínio Portal do Anhanguera Rua B nº: 132. Bairro Macuco, Valinhos – SP CEP: 13279-411 Fone/Fax: 55-(19)3869-1478 - falecom@hotsound.com.br
