The attack and release times are switchable rather than being continuously variable and this method of operation falls into line with that of its all valve predecessors. Attack simply offers a-choice of slow, medium and fast whilst release has six settings. Positions one to four have fixed release times whilst positions five and six are two different programme dependent release time modes making the unit ideally suited to programme material with complex dynamics such as complete stereo mixes and vocals. Interestingly, the attack times are further modified by the choice of release setting so the range of choices are wider than it might first appear.

Because compression is a form of controlled gain reduction, a stage of make-up amplification follows the compressor section giving a range of +20dB. The VU meters may be switched to monitor either the amount of gain reduction taking place or the output signal level and the two channels may be used either independently or as a stereo pair, depending on the setting of the stereo link switch.

The side chain access points may be used to patch in equalisers to enable the compressor to act as a de-esser. As with other Drawmer products, the by-pass switch offers a choice of Normal. By-pass and Side Chain Listen modes so that if you have patched in any additional side chain processing, you can easily monitor what effect it is having.

In addition to the balanced microphone and line inputs on the rear of the unit an auxiliary input on the front panel gives direct access for guitars or electronic instruments. Equalization is provided along with sufficient gain to overload the tube pre-amp for sustain effects. The Aux input is a valuable addition as it combines the virtues of a D.I. box and equalizer with the compressor allowing the instrument to be simultaneously processed and routed to the mixing console or directly to the recorder.

Features

• CONTROL DESCRIPTION
  With the exception of the Aux preamp section, both channels of the 1960 are identical and may be used independently or linked for stereo operation. In linked mode, the compressor controls should, ideally, be set to the same settings (as the control-circuitry for both channels responds to the average between the two channel settings). In Stereo Link mode, both channels track together to avoid the inevitable image shifting that would occur if the two channels of a stereo signal were treated independently.
• COMPRESSOR
  Source Select: This rotary switch selects the compressor input source. The Line and Mic inputs are via the rear-panel XLRs while the Aux input is available on the front panel. The two Mic positions offer a choice of Mic input with or without +48V phantom powering; a red LED indicates that phantom power is active.
  Note: if the Aux input is to be used at the same time as a Mic input, it is recommended that the Mic input be processed through the upper channel and the Aux input through the lower channel as this minimises crosstalk between tube amplification stages sharing the same envelope.
• High-pass: The signal path incorporates a switchable high-pass filter which may be set to 50Hz, 100Hz or Off. Its use is to attenuate low frequency signals that might otherwise prove troublesome, eg. traffic rumble or stage vibration.
• Threshold: Determines the input level above which gain reduction will be applied and may be set in the range -24dB to infinity. Because the compression system is based on the Soft Knee principle, the onset of compression is progressive, so no Ratio control is necessary.
• Attack: Three switchable Attack settings are provided giving Fast, Medium and Slow attack times. The actual attack time is further modified by the release setting chosen.
• Release: There are four fixed Release times and a further two which are programme dependent. Switch settings 1 through to 4 provide progressively increasing release times, while positions 5 and 6 cause the release times to vary in a manner which automatically adapts to the dynamics of the incoming signal.
• Output: (Gain) The Output level may be amplified or attenuated by up to 20dB to compensate for level changes caused by compression and limiting.
• VU Meter: A moving coil VU meter monitors either the level of the output signal (over the range -10dB to +10dB with reference to the +4dBu operating level) or the amount of gain reduction taking place. Because the meter has VU characteristics, it closely reflects what is actually being heard, though will not respond quickly enough to register short signal peaks.
• VU / GR: Switches the meters to show either the output level (VU) or the amount of gain reduction (GR).
• Norm/Bypass, S/C Listen: In Normal mode, the signal is passed through the compressor. Bypass only takes the compressor out of circuit leaving the vacuum tube warmth in the circuit path; the output signal is taken from the signal insert return point. S/C Listen routes the side-chain signal directly to the output allowing the effects of any additional side-chain processing, such as equalisation, to be monitored.
• Stereo Link: Averages the left and right channel control settings when the unit is used for processing a stereo signal. The same degree of gain reduction is applied to both audio channels to prevent image shifting which would otherwise occur whenever the left and right signal dynamics varied from each other by any significant degree.
• MICROPHONE PRE-AMPLIFIER
  Mic Input Gain: This fully variable control sets the mic input gain over the range 0 to 60dB. The adjacent Clip LED illuminates when excessive mic gain has been applied and there is a danger of clipping.
• AUXILIARY INPUT
  The Auxiliary Input feeds a specialised instrument input stage which provides both gain and equalisation. The passive Bass and Treble controls are based on those used in classic tube guitar amplifiers while the Bright switch puts a peak in the frequency response at around 2kHz to simulate the voicing of a typical guitar amplifier. A two position high or low gain switch provides an additional 10dB of gain when required for level matching or for creating overdrive effects.
• Bass EQ: Passive equaliser control, which can be set to provide up to 15dB of bass boost at 40Hz.
• Treble EQ: Passive equaliser control, which can be set to provide up to 18dB of treble boost at 16kHz.
• Gain: Provides up to 30dB of gain at the Low Gain switch setting or 40dB at the High Gain setting.
• Low/High: Sensitivity selector switch. Adds 10dB of gain in the High position.
• Flat/EQ: Switches the equaliser controls out of circuit when a flat response is required, or for 'A/B' comparison of EQ effectiveness.
• Norm/Bright: Switches in 10dB of boost at 2kHz in the Bright position, ( when 'EQ' has been selected on the Flat/EQ switch.) 

Specifications

(All measurements taken at +4dBu operating level)

• INPUT IMPEDANCES
  LINE 20K Ohm
  MIC 150 Ohm to 600 Ohm
  AUX 2.2M Ohm
• MIC INPUT NOISE -128.5dB (@ +60dB gain)
  MAXIMUM INPUT LEVEL +20dBu
• OUTPUT IMPEDANCE 50 Ohm
• MAXIMUM OUTPUT LEVEL +22dBm (balanced)
• BANDWIDTH <10Hz to 22KHz -1dB
• DISTORTION (THD & NOISE) 1KHz
  Line Input with BYPASS selected < 0.1%
  Line Input with NORMAL selected < 0.3%
• POWER REQUIREMENTS 100-120Volt or 195-250Volt at 50-60Hz, 38 Watts
• FUSE RATING 250mA for 240Volt, 500mA for 120Volt
• CONFORMING TO BS EN 60127-2:1991 SHEET III
• FUSE TYPE 20mm x 5mm, Class 3 Slo-Blo, 250Volt working
• CASE SIZE 482mm (w) x 88mm (h) x 250mm (d)
• WEIGHT (incl packaging) 6.0 Kgs
• RELEASE TIMES
  1 400 ms
  2 1 sec
  3 2 sec
  4 4 sec
  5 Automatic 400 ms to 2 sec signal dependant
  6 Automatic 200 ms to 20 sec signal dependant