Avalon VT-737SP | Channel Strip


Shipping in 1-2 working days
  • A Legend Channelstrip
  • distinct modern tube sound
  • Mic / Line / Instrument Input Level
  • Opto Compressor
  • 4-Band EQ

Produkt vergleichen SKU: AVALON-VT-737SP Categories: ,

The Avalon VT-737SP offers a combination of TUBE preamps, opto-compressor, sweep equaliser, output level and VU metering in a 2RU unit.

The VT-737SP has three input selection options: 1. the VT-737SP has a more powerful microphone input transformer with +48V phantom power. 2. instrument DI high source input with socket on the front panel. 3. balanced line input, discrete high level class A amplifier. The Class A preamplifier uses two cascaded, dual tube triodes configured with minimal negative feedback. A high-gain switch increases the overall gain of the preamp. The four high-quality tubes are configured as anode-coupled single-ended followers. A passive variable high-pass filter and a hard-wired relay bypass complete the input signal processing. The phase reversal relay is available on all three inputs.

The optocompressor features a minimal signal path with two Class A vacuum tube triodes for gain matching. The optical attenuator serves as a simple passive level control. With the controls for threshold, ratio compression, attack and release as well as the selection of gain reduction on the large VU meter, the full dynamic range from soft compression to hard knee limiting can be set. Special spectral control including de-ess is possible with the Dual Sweep Mid EQ to Side-Chain switch. The EQ section can be switched before or after the opto compressor via a switch on the front panel to allow alternative effects and sound shaping. Two VT-737SPs can be connected via a rear connection cable for stereo tracking. The compressor bypass is a sealed silver relay for the most direct signal path possible.

The VT-737SP’s equaliser uses 100% discrete class A high voltage transistors for optimum sound performance. The high and low frequency bands offer the uniform characteristics of a purely passive design, while the two middle bands have a variable frequency and a switched Q-width. The extended range of the centre bands is extended to the high and low frequency bands through the use of X10 frequency multipliers. The bypass switch is equipped with a sealed silver relay to ensure the most direct signal path possible. When EQ to sidechain is activated, the high-low EQ remains in the audio path for “sound enhancement”. The output level control allows variable control of the entire signal path. The output amplifier uses another double triode vacuum tube to drive a 100% discrete, high current, balanced and DC coupled low noise output amplifier.

  • Special performance
  • distinct tube sound
  • Mono Mic pre/opto-compressor
  • 4-band EQ
  • four tubes + Class A discrete electronics
  • Mic Line and DI Inputs
  • Circuit Topology: Four dual-triode vacuum tubes (Sovtek 6922) in a high-voltage discrete Class A circuit.
  • Gain Range:
    – Microphone: Transformer balanced, 850/2500 ohms, 0 dB to +58 dB.
    – Instrument: Unbalanced, 1 megohm, 0 dB to +30 dB.
    – Line: Balanced, Class-A, 20k ohms, -27 dB to +28 dB.
  • Max. Input levels and connection types:
    – Microphone: 26 dB @ 25 Hz, +30 dB @ 1 kHz, balanced XLR.
    – Instrument: +30 dB, unbalanced front panel jack.
    – Line: +36 dB, balanced XLR.
  • Max. Output level: +30 dB, balanced 600 ohms, DC-coupled, discrete Class-A.
  • Output type and gain: XLR connector, output level trimmable from -45 dB to +20 dB.
  • Noise (20 kHz unweighted): -92 dB.
  • Noise Microphone (ON): -116 dB, 22 Hz to 22 kHz, unweighted.
  • Distortion (THD, IMD): 0.5%.
  • Frequency response -/2.5 dB: 10 Hz to 120 kHz (with input filter).
  • Frequency response -3 dB: 1 Hz to 200 kHz (Line In-Out).
  • VU meter and gain reduction: High quality illuminated OVU = +4 dB and gain reduction up to -20 dB.
  • High-pass filter: Variable filter, 6 dB per octave, 30 Hz to 140 Hz.
  • Compressor type: Optical passive attenuator with two vacuum tubes and stereo link.
  • Threshold – Ratio: Threshold variable from -30 dB to +20 dB, Ratio compression variable from 1:1 to 20:1.
  • Attack – Release: Attack variable from 2 ms to 200 ms, Release variable from 100 ms to 5 seconds.
    – Equalizer type: Discrete Class-A, variable active and switched passive design.
  • Frequency bands (4):
    – Treble: Switched at 10 kHz, 15 kHz, 20 kHz, 32 kHz, +/- 20 dB range, Shelf.
    – High-mids: variable from 200 Hz to 2.8 kHz and from 2 kHz to 28 kHz, +/- 16 dB range, Hi-Lo Q.
    – Low-mids: Variable from 30 Hz to 450 Hz and from 300 Hz to 4.5 kHz, +/- 16 dB range, Hi-Lo Q.
    – Bass: Switched at 15 Hz, 30 Hz, 60 Hz, 150 Hz, +/- 24 dB range, Shelf.
  • AC power supply: Internal toroidal transformer, selectable from 100 V to 240 V, 50-60 Hz, maximum power 75 watts.


Vacuum tube triode signal path, transformer balanced mic input, high voltage circuits for maximum headroom up to +30dB, low noise -92dB, internal discrete power supply with toroidal transformer, soft-start tube life extension, stereo link for compressors, fully discrete Class A equaliser with musical passive filter design, sealed silver relays for signal routing, large rotary controls with professional conductive plastic potentiometers, VU meter for output level monitoring and compressor gain reduction.

VT-737SP User: Christina Aguilara, Orgy, Motley Crue, Snoop Dogg, Bob Dylan, The Crystal Method, Michael Jackson, Phil Collins, Puff Daddy, Crazy Town, AC/DC. Disney Productions.

Applications: Vocals, guitars, bass, keyboards, electronic synthesizers. All instruments that require a soft tube sound. Need for compressor and EQ. Can be used as a compressor / equalizer for mixdown and mastering (stereo link) – the Swiss army knife for all recordings.

Sound: Round, warm sound, EQ delivers soft highs – deep, powerful bass, musically balanced with good “presence”.

Q: Is the microphone preamp of the Vt-737sp the same as that of the AD2022 or M5?

A: No!

The Vt-737sp and the AD2022/M5 are very different microphone preamps. The Vt-737sp uses vacuum tubes, while the AD2022/M5 is 100% discrete transistor electronics (no vacuum tubes). The AD2022 and the M5 use the same basic amplifier topologies. The AD2022 has a fully balanced output and a variable input impedance that can be used to change the sound of all microphones. All Avalon microphone preamps operate in “Pure Class A” mode and use only discrete electronics for amplification. Tube preamps offer a very different sound than solid-state preamps.

Avalon’s designer Wynton R. Morro believes that tubes produce a very unique and wonderful sound. The AD2022/M5 is a higher quality microphone preamplifier than the Vt-737sp. The AD2022/M5 has more detailed highs, better low frequency definition, and is much quieter.

The sonic differences between the Vt-737sp and the AD2022/M5 can be compared to a spotlight (Vt-737sp) and a floodlight (AD2022/M5). The Vt-737sp has a “close”, round sound, while the AD2022 is very detailed and open, capturing more of the subtle subharmonics and reflections in the room.

Now all owners of the Vt-737sp might think that they might have bought the wrong preamp. On the contrary, the Vt-737sp is a fabulous device. It was the first and is still the best “Direct Recording Channel” or “Channel Strip” on the market, at any price – without exception.

The Vt-737sp was specifically designed as a tube preamp and has the unique sound that only tubes can deliver. The Vt-737sp is the clearest, most transparent, powerful and controllable tube preamp on the market. The Vt-737sp is a Swiss Army Knife for recording, with the necessary powerful features to meet all your real-world recording needs: Preamp, Compressor and Parametric Equalizer.

Should you trade in your Vt-737sp for an AD2022/M5? No, but you might need both preamps in your preamp collection. Try both preamps and experience the difference in sound for yourself.


EQ Type

Semiparametric, Shelf / Baxandall

Frequency bands



Instrument (Hi-Z), Line, Microphone

+48 Volt phantom power






Compressor Type




Einheiten (HE)



unsym. Jack, XLR


Black, Silver


There are no reviews yet

Only logged in customers who have purchased this product may leave a review.

Q & A

There are no questions yet

Ask a question

Your question will be answered by a store representative or other customers.

Thank you for the question!

Your question has been received and will be answered soon. Please do not submit the same question again.



An error occurred when saving your question. Please report it to the website administrator. Additional information:

Add an answer

Thank you for the answer!

Your answer has been received and will be published soon. Please do not submit the same answer again.



An error occurred when saving your answer. Please report it to the website administrator. Additional information:

My Cart
Recently Viewed
Select the fields to be shown. Others will be hidden. Drag and drop to rearrange the order.
  • Image
  • SKU
  • Rating
  • Price
  • Stock
  • Availability
  • Add to cart
  • Description
  • Weight
  • Dimensions
  • Dimensions
  • Amp Class
  • Number of analog outputs
  • Number of analog inputs
  • Ausbreitungsgeschwindigkeit
  • Bend radius
  • Kapsel
  • Channels
  • Color
  • Compressor Type
  • Resistance conductor
  • Port
  • Connector Brand
  • Connector Type
  • Conversion
  • Attenuation at 100 MHz
  • Attenuation at 500 MHz
  • Constant power
  • Durchmesser Isolierung
  • Conductor Size
  • Eingangsimpedanz
  • EQ Type
  • Farad Core to Core
  • Farad Core to Screen
  • Format
  • Frequency bands
  • Overall diameter
  • Höhe
  • Impedance
  • Insulation
  • Jacket
  • Headphone Jack
  • Conductor cross-section
  • Length in metre
  • Max. Samplerate
  • Max. Bitrate
  • max. Kabeldurchmesser
  • Max. Power
  • Mikrofon Ausführung
  • Number of microphones
  • mind. Kabeldurchmesser
  • Modul Position
  • Modulerhöhung
  • Modulgröße
  • Pairs
  • Patchmode
  • +48 Volt phantom power
  • Polanzahl
  • Preamp
  • Room Correction
  • Insulation resistance
  • Directional characteristic
  • RMS Power
  • Röhren-Sockel
  • Röhren-Typ
  • Side-Chain
  • Signal Level
  • Modification
  • Steckzyklen
  • Speaker System
  • Übertrager
  • Transmission protocol
  • Tube
  • Einheiten (HE)
  • Vergoldet / Versilbert
  • Version
  • Mic Converter
  • Winkel