Drawmer 1961 - 2-Channel Mastering Tube Equalizer

It has long been recognized that vacuum tubes impart a unique 'warmth' and 'musicality' to an audio signal, but many of the 'classic' tube equalizers fall short of the technical performance demanded in today's digital recording age.

Designed to complement the widely acclaimed Drawmer 1960 Mic Pre-Amp Vacuum Tube Compressor, the 1961 Vacuum Tube Equalizer combines low noise circuitry with no fewer than twelve active tube stages to provide two channels of exceptional equalization possessing unique 'personality'. Rather than employ a continuously variable resistor as a means of frequency control, the 1961 utilizes the same rotary 'step' switching system used in vintage designs . This enables the component values for each frequency band to be optimized for uncompromising performance across the entire audio spectrum and also makes setting up more accurate, particularly when treating stereo signals.

The design of the 1961 allows the user to control the amount of 'warmth' by deciding how hard to drive the tubes giving a sound as 'clean' as the best discrete solid state designs or as 'hot' as the 'hottest' classic tube designs. The 1961 and 1960 Can be 'interlinked' to provide, in effect, a two channel vacuum tube mixing console, - the perfect mastering or post audio 'sweetening' tool.

Features

Input level

A variable input level of -20dB to +20dB ensures compatibility with a wide range of input source material and enables the user to optimize signal level and drive the tubes 'soft' or 'hot' as required. LED bargraph displays give a clear indication of the input signal level.

High Pass Filter

A variable 12dB/Octave roll-off filter adjustable from - 20Hz to 500Hz section enables the user to remove unwanted low frequencies and sub-sonic noise.

Equalization

Each channel of the 1961 has four main equalizer sections with six carefully chosen overlapping frequencies and a separate tube stage for increased harmonic clarity. Each section also includes variable band width from 0.3 Octave to 3 Octaves and +18dB of Cut and Boost.

Bass frequencies (Hz) 20, 32, 50, 80, 125, 200
Lo-Mid frequencies (Hz) 100,180, 250, 400, 650,1K
Hi-Mid frequencies (kHz) 0.5, 0.8,1.2, 2.0, 3.2, 5.0
Treble frequencies (kHz) 2.5, 4, 6,10,15, 25

Low Pass Filter

A variable 12dB/Octave roll-off filter adjustable from 2.5kHz to 42kHz enables the user to remove high frequency interference or to band limit excessively high levels of high frequencies.

Output Stage

Two additional tube stages in the output section of each channel allow the user to achieve 'soft clipping' by adjusting the input level control whilst visually monitoring the effect upon the 'Soft' and 'O/L' (Overload) LED's.

Bypass

In addition to a master bypass switch for each channel each of the parametric and shelving filters has its own separate bypass switch. This not only makes the 1961 very straight forward to set up, by allowing instant A-B comparison ,but also enables the tube output stages to be used to add tube coloration without EQ simply by leaving each channel switched to 'In' and each individual EQ sections switched to 'Out' The master bypass switch for channel bypasses all the filter sections as well as the output stage vacuum tube circuitry.

Operating Level

Levels of -10dBu and +4dBu are selectable using a rear panel switch.

Insert Connections

Insert point 1/4" jack connectors on the rear panel enable direct connection to the Side chain or Insert points of the Drawmer 1960 Mic Pre-Amp/ Vacuum Tube Compressor. The 1961 and 1960,when'interlinked', produce a powerful package for recording signals direct to tape; gain control, EQ and compression can be applied to both mic and line level signals without having to go via a mixing console.

Inputs and outputs

The 1961 is provided with balanced inputs and outputs on XLR connections.

Specifications

• Input Impedances
  • XLR: 20K Ohm
  • Insert: 47K Ohm
• Maximum Input Level +17dB (+21dBu)
• Output Impedances
• XLR 50 Ohm
• INSERT 200 Ohm
• Frequency Response: <22Hz to 42KHz -1dB
• Crosstalk
  • <-80dB @ 10KHz
  • <-75dB @ 20KHz
• Input Cmr: Better than 40dB (20Hz to 10KHz)
• Output Balance: Better than 40dB (20Hz to 10KHz)
• Noise At Unity Gain with flat EQ response switched in circuit @ 22Hz - 22KHz
  • AV: -94dB
  • RMS: -92dB
• Distortion @ 1KHz
• XLR Input with Bypass selected < 0.1%
• XLR Input with Normal selected < 0.3%
• Power Required: 115 Volt or 230 Volt AC at 50-60Hz, 28 Watts
• Fuse Rating: 250mA for 230 Volt, 500mA for 115 Volt
• Fuse Type: 20mm x 5mm, Class 3, Time delay, 250 Volt working
• Case Size: 482mm (w) x 88mm (h) x 250mm (d)
• Weight: 6.1 Kgs

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