AVALON VT-737SP DIRECT SIGNAL PATH

The Avalon VT-737SP features a combination of TUBE preamplifiers,
opto-compressor,sweep equalizer, output level and VU metering in a
2U space.
PREAMPLIFIER
The VT-737SP has three input selections: 1. The VT-737SP features a
higher-performance microphone input transformer with +48v phantom
selection. 2. Instrument DI high source input with jack located on front
panel. 3. Balanced line input, discrete high-level Class A. The Class A
preamplifier utilizes two cascaded, dual vacuum tube triodes configured
with minimum negative feedback. A high gain switch boosts the overall
gain of the preamplifier. The four high quality tubes are configured as
singled ended anode coupled followers. A passive-variable high pass filter
and hard-wire relay bypass completes the input signal conditioning. The
phase reverse relay is available on all three inputs.
OPTO-COMPRESSOR
The opto-compressor features a minimum signal path design with twin Class
A vacuum tube triodes for gain matching. The optical attenuator acts as a
simple passive level controller. Full dynamic control from soft compression to
hard- knee limiting can be achieved with threshold, ratio-compression, attack
and release controls plus gain reduction selection on the large VU meter. Special
spectral control including de-ess is available with the dual sweep mid EQ to side-
chain switch. The EQ section can be flipped pre or post the opto-compressor
via a front panel switch for alternate effects and tone shaping. Two VT-737SPs
can be linked via a rear panel link cable for stereo tracking. The compressor
bypass is a sealed silver relay for the most direct signal path.
SWEEP-EQUALIZER AND OUTPUT LEVEL
The VT-737SP equalizer utilizes 100% discrete, Class A-high-voltage transistors
for optimum sonic performance. The high and low frequency bands provide the
smooth characteristics of an all passive design, while the dual mid bands include
variable frequency and switched Q-width selection. The enhanced range of the mid
bands is extended into the high and low bands by the use of X10 frequency multipliers.
The bypass switch incorporates a sealed silver relay for the most direct signal path.
When the EQ to sidechain is engaged, the high-low EQ remains in the audio path for
"tone enhancement“. The output level control provides a variable control of the overall
signal path. The output amplifier utilizes another dual triode vacuum tube driving a
100% discrete, Class A, high-current, balanced and DC coupled low noise output
amplifier.

AVALON VT-737SP FEATURES
Vacuum tube triode signal path, transformer balanced microphone input, high-voltage
circuits for maximum headroom to +30dB, low noise -92dB, internal discrete power
supply with toroidal transformer, soft-start tube life extender, stereo link for compressors,
all discrete Class A equalizer with musical passive filter design, sealed silver relays for
signal routing, large control knobs with professional conductive plastic potentiometers,
VU meter for output level monitoring and compressor gain reduction.

VT-737SP SPECIFICATIONS
Circuit topology Four dual triode vacuum tubes (Sovtek 6922), high-voltage discrete
Class A
Gain Range Microphone: Transformer balanced 850/2500 ohm, 0dB to +58dB Instrument:
Unbalanced 1 meg ohm, 0dB to+30dB Line: Balanced Class A 20k ohms, -27dB to 28dB
Maximum input level and connector types Microphone26dB@25Hz, +30dB@1kHz balanced
XLR Instrument+30dB unbalanced front panel jack socket
Line +36dB balanced XLR
Maximum output level +30dB balanced 600 ohms, DC coupled, discrete Class A
Output type and gain XLR connector, output trim gain -45dB to20dB
Noise 20kHz unweighted -92dB
Noise microphone EIN -116dB, 22Hz to 22kHz unweighted
Distortion THD, IMD 0.5%
Frequency response -/2.5dB 10Hz to 120kHz input filter included
Frequency response -3dB 1Hz to 200kHz line in-out
VU meter and gain reduction High quality illuminated OVU =+4dB and gain reduction to -20dB
High cut filter Variable 6dB per octave 30Hz to 140Hz
Compressor type Optical passive attenuator incorporating twin vacuum tubes and stereo link
Threshold - Ratio Threshold variable -30dB to +20dB, ratio-compression variable 1:1 to 20:1
Attack - Release Attack variable 2mS to 200mS, release variable 100mS to 5 seconds
Equalizer type Discrete Class A, variable active and switched passive design
Frequency bands (4) Treble - switched 10kHz, 15kHz, 20kHz, 32kHz, +/- 20dB range, shelf
High mid - variable 200Hz to 2k8Hz and 2kHz to 28kHz, +/- 16dB range, hi-lo Q Low mid -
variable 30Hz to 450Hz and 300Hz to 4k5Hz, +/- 16dB range, hi-lo Q Bass - switched 15Hz,
30Hz, 60Hz, 150Hz, +/- 24dB range, shelf
AC power Internal toroidal 100v to 240v, 50-60Hz selectable, 75 watts maximum
Dimensions 19 x 12 x 3.5 in (482 x 305 x 89mm)
Weight 22lbs (10kg)
Dimensions-shipping carton 21 x 18 x 8 in (533 x 457 x 203mm)
Weight-packed 26lbs (11.8kg)

• Error proof operation to smooth uneven levels, add sustain to guitars, fatten drums or tighten up mixes
• New gate timing algorithms ensure the smoothest release characteristics
• Program-adaptive expander/gates
• Great sounding dynamics control for any type of program material
• Separate precision LED displays for gain reduction, compression threshold and gate threshold allow quick, accurate setup
• Stereo or dual-mono operation
• Balanced inputs and outputs on 1/4" TRS and XLR connectors
• Side Chain insert
• Classic dbx® "Auto" mode

GENERAL DATA
Power Supply 220 / 110V 25 VA
Dimension 434x351x44mm (1 rack unit)
Weight » 4 Kg
MEETING INTERFACE IN / OUT
Connector DB 9 female
Nominal in / out audio level 0 dBm
Input impedance 600 W / 10 KW (selectable)
Output impedance 100 W
* nominal line level: - 6 dBm
** it can vary depending on characteristics of telephone line
All measurements are intended at 1 kHz.
AUDIO PROGRAM IN / OUT
Connectors XLR, electr. balanced
Input impedance 600 W / 10K W (selectable)
Output level * - ¥ ¸ + 16 dBm
Output impedance 100 W
Noise on Receive output 2-Wire separation £ 25 dB**
4-Wire separation £ 70 dB
2-WIRE SECTION
Connector RJ11
Nominal input level - 6 dBm
Nominal output level - 6 dBm
Compensation mode Electronic, transf. decoupled
Impedance 600 W
4-WIRE SECTION
Connector Terminal block
Impedance 600 W
Nominal TX level 0 dBm
Nominal RX level 0 dBm

Shure DP11EQE Dynamics Processor Specification:

    GENERAL:
        Frequency Response: 20 to 20k Hz +/- 1.0 dB re 1 kHz
        Dynamic Range: 104 dB minimum, A-weighted, 20 Hz to 20 kHz
        Sampling Rate: 48 kHz
        Digital-to-Analog, Analog-to-Digital Conversion: 20 bit resolution
    Voltage Gain:
        1 dB +/- 1dB (power off)
        12 dB +/- 2 dB (input 10 dBV, output +4 dBu)
        12 dB +/- 2 dB (input +4 dBu, output 10 dBv)
        0 dB +/- 2 dB (equal input and output sensitivities)
    Impedance:
        Input: 47 kilohms +/- 20% actual
        Output: 120 ohms +/- 20% actual
    Input Clipping Level
        +18 dBu minimum (at +4 dBu setting)
        +6 dBV minimum (at 10 dBV setting)
    Output Clipping Level
        +18 dBu minimum (at +4 dBu setting)
        +6 dBV minimum (at 10 dBV setting)
    Total Harmonic Distortion
            LED Signal Indicators
        Signal: 40 dB
        Clip: 6 dB down from input clipping
    Propagation Delay from Input to Ouput
        0.8 ms (all filters flat, no dynamics processing, 0 ms delay), up to 2.1 ms (all processing enabled)
    Polarity
        Input to output: inverting optional (default: non-inverting)
        XLR: pin 2 positive with respect to pin 3
        1/4-inch TRS: tip positive with respect to ring
    Operating Voltage
        DP11EQ: 120 Vac, 50/60 Hz, 50 mA max
        DP11EQE: 230 Vac, 50/60 Hz, 25 mA max
        DP11EQJ: 100 Vac, 50/60 Hz, 50 mA max
    Temperature Range
        Operating: 0 degrees to 60 degrees C (32 degrees to 140 degrees F)
    Fuse
        DP11EQ: 120 Vac. Fuse: 100 mA, 250V time delay
        DP11EQE: 230 Vac. Fuse: 50 mA, 250 V time delay
        DP11EQJ: 100 Vac. Fuse: 100 mA, 250 V time delay
    Dimensions
        219 mm x 137 mm x 44 mm (8-5/8 in x 5-3/8 in x 1-3/4 in)
        Weight: 930 g (2.05 lbs)
    DYNAMICS PROCESSOR
        Gate and Expander:
        Threshold: 72 to 1 dB, 0.5 dB resolution
        Attack: 1.0 to 200 ms
        Decay: 0.05 to 1 second
        Gate Hold Time: 0 to 0.5 seconds
    AGC Leveler
        Threshold: 72 to 1 dB, 0.5 dB resolution
        Attack: 0.2 to 3 seconds
        Decay: 0.5 to 5 seconds
        Hinge: Threshold to 1 dB, 0.5 dB resolution
    Compressor and Limiter
        Threshold: 72 to 1 dB, 0.5 dB resolution
        Attack: 1.0 to 200 ms
        Decay: 0.05 to 1 second
        Knee: Hard or Soft selectable
    No Overshoot Peak Limiter
        Propagation delay: 1 ms
        Threshold: 72 to 1 dB, 0.5 dB resolution
        Attack: 0 msDecay: 100 ms
    PARAMETRIC EQUALIZER
        Parametric Filter Frequency Bands
        Up to 9 bands, variable frequency, variable Q
    Boost/Cut Range
        +6 dB to 18 dB per band
        Q Range
        1/40-octave to 2 octave
    High and Low Shelf/Cut Filters
        Shelf, +6 to 18 dB per filter
        Cut, 12 dB per octave nominal
    DELAY
        Up to 1.3 seconds, 21 microsecond resolution

Product Features:

Ultra-high resolution 24-bit/96 kHz mastering processor featuring 32/40-bit floating-point DSP technology
Audiophile 24-bit/96 kHz A/D- and D/A converters offering 113 dB dynamic range
4 concurrently selectable EQ modules (31-band graphic EQ, 10-band parametric EQ, Feedback Destroyer plus 3 Dynamic EQs per stereo channel)
Ultra-high resolution 61-band real-time FFT analyzer with additional auto EQ function for room and loudspeaker equalization
Unique VPQ (Virtual Paragraphic EQ) option allows parametric control of graphic EQs
State-of-the-art compressor/expander with peak limiter per stereo channel, additional stereo imager and stereo delay for delay line applications
Multi-functional level meters (peak/RMS, VU and SPL meter with dBA/dBC weighting via RTA/Mic input)
64 user memories for complete setups and/or individual module configurations
Separate mic/line input with phantom power for RTA and Auto-EQ applications
Balanced inputs and servo-balanced outputs with gold-plated XLR connectors, stereo aux output, AES/EBU and S/PDIF inputs and outputs (XLR and optical)
Professional Wordclock input and MIDI connections for full remote control, preset dumps and system updates
Open architecture allowing future software updates via MIDI
"Planet Earth" switching power supply for maximum flexibility (100 - 240 V~), noise-free audio, superior transient response plus low power consumption for energy saving
High-quality components and exceptionally rugged construction ensure long life
Conceived and designed by BEHRINGER Germany

compression
Stereo couple function selectable for channels 1/2 and 3/4
Ultra low-noise 4580 operational amplifiers and state-of-the-art THAT¬ VCA's
Separate 8-segment LED meters for input/output levels and gain reduction
Selectable operating level (+4 dBu/-10 dBV)
High-quality detented ALPS¬ potentiometers and illuminated switches
Servo-balanced inputs and outputs with ? in. TRS and gold-plated XLR
connectors
Manufactured under ISO9000 certified management system