DISC Midas 501 Microphone Preamplifier

Full Description

Significantly-Upgraded Award-Winning MIDAS Mic Preamp

Considered by leading engineers to be the definition of the famous MIDAS sound, the MIDAS microphone preamp has been expertly crafted through decades of precision design experience and premium-grade components to achieve truly astounding sonic characteristics. The MIDAS preamp is perfect for accurately capturing the desired sonic image, and can be heard in countless concerts and recordings. The MIDAS preamp in the 501 module utilises an upgraded design with ultra-low noise octal discrete input transistors for truly transparent operation, as well as exceptional sonic flexibility and dynamic control.

Ultimate Power & Flexibility

The MIDAS preamp within the 501 utilises a design that has become renowned for providing an incredible sound when driven hard. Thanks to the design of the 501's input stage, the module allows up to +24dBu signal levels with no requirement for a pad. Simultaneously, the soft-clipping characteristic that provides crystal-clear audio reproduction with the perfect amount of harmonic content ensures truly astounding results for your recordings and live performances. The 501 also features a unique 'Warm' mode, engaged via a toggle switch that inserts a premium-quality balanced input transformer in front of the preamp. This lowers the input impedance from 10 k Ohms down to 1.5 k Ohms, as well as providing the benefits of galvanic isolation to the microphone input, resulting in a beautiful vintage sound and setup.

Ultra-Precise Metering & Controls

Boasting impressive high-precision 31-segment rotary LED meters, the 501 reads the signal post-amplifier/pre-filter to provide input metering from -20dBu up to +20dBu in 1 and 2dB steps, as well as output metering in the same range. The 501's input gain can be adjusted using the large precision 12-position rotary switch with gain settings ranging from 0 to +60dB in 5dB increments. The output trim is adjustable using a fully-variable potentiometer across a +/-20dB range. When used together, you can achieve a phenomenal +80dB maximum gain, perfect for even the lowest-level ribbon microphones.

Features

• Ultra-high performance microphone/line/DI preamplifier that offers outstanding signal integrity
• Significantly upgraded version of the award-winning MIDAS mic amp design that gives you the best preamp ever in MIDAS' 40-year history
• Ultra-low noise octal discrete input transistors provide incredible sonic flexibility and dynamic control
• Legendary MIDAS input allows up to +24dBu signal levels with no pad whilst giving you the MIDAS signature soft-clip colouration on overload
• Unique 'Warm' feature reconfigures the input stage with a premium input transformer for lower input impedance and an authentic vintage sound
• Separate high-performance DI input through secondary rack connector and easy-access front panel switch let you effortlessly switch between mic and instrument
• Twin circular 31-segment meters with precision full wave rectifiers for unprecedented visibility into your input and output levels for exceptional signal monitoring accuracy
• Stunning aesthetics with a distinctive fusion of vintage and modern design with an anodized fascia, metal controls, and 4 gold-plated rings for class-leading style
• Separate discrete transformer- and electronically-balanced outputs provide a splitter function and give you a choice of sonic characteristics
• High-accuracy Mil-Spec rotary switch gain and output gain trim controls provide you with a phenomenal combined mic input gain range of -20dB to +80dB
• Fully-variable high- and low-pass wide-spectrum filters with independent selection switches allow you to perfectly sculpt the frequency spectrum to your exact preference
• Front-panel toggle switches enable easy-to-use control over input select, filters, +48V, polarity, output mute, and 'Warm' mode
• Protective auto-mute feature guards against accidental unwanted noise from input switching in live and studio applications
• Premium-grade components are used throughout, including high-end op-amps, micro melf resistors, and discrete FETs, providing you with the highest form of signal integrity
• Designed and engineered in the UK

Specifications

Controls

• Input Select: Mic/DI switch (relay)
• Phantom Power: 48V switch (discrete FET switched)
• Input Gain (Mic/Line): 12-position rotary switch, 0 to 60dB
• Input Gain (DI): 12-position rotary switch, 0 to 40dB
• Polarity: 0/180 degrees switch (discrete FET)
• Low-Pass Filter: In/out switch (discrete FET), frequency knob
• High-Pass Filter: In/out switch (discrete FET), frequency knob
• Output Trim: +/-20dB knob, fully variable
• Warm (Input Transformer): In/out switch (relay)
• Mute: In/out switch (discrete FET)

Inputs & Outputs

• Lower Numbered Module Input: Mono, balanced mic or line
• Higher Numbered Module Input: Mono, balanced DI (Hi-Z)
• Lower Numbered Module Output: Mono, transformer balanced
• Higher Numbered Module Output: Mono, electronically balanced

Noise (22Hz to 22kHz Unweighted, Transformer Output)

• Mic/Line/DI Noise (at unity gain, 150-Ohm source):
  • Warm Disabled: -98dBu
  • Warm Enabled: -102dBu
• Mic EIM Noise (at +60dB gain, 150-Ohm source, warm disabled): -128dBu
• Mic EIM Noise (at +60dB gain, 50-Ohm source):
  • Warm Disabled: -130dBu
  • Warm Enabled: -125dBu
• Noise When Muted: -105dBu

CMRR (1kHz, Transformer Output)

• Mic/Line Input (at unity gain):
  • Warm Disabled: Typically -70dBu
  • Warm Enabled: Typically -100dBu
• DI Input (at unity gain):
  • Warm Disabled: Typically -60dBu
  • Warm Enabled: Typically -90dBu
• Mic Input (at +60dB gain):
  • Warm Disabled: Typically -90dBu
  • Warm Enabled: Typically -115dBu

Input Impedance (1kHz)

• Mic/Line Input:
  • Warm Disabled: 10 k Ohms
  • Warm Enabled: 1.5 k Ohms
• DI Input: 1 M Ohm

Frequency Response (+0dB/-1dB, Transformer Output)

• Mic/Line/DI Input (at unity gain): 20Hz - 30kHz
• Mic Input (at +60dB gain): 20Hz - 30kHz

Distortion (0dBu Output Level, 1kHz)

• Mic/Line/DI Input (at unity gain, transformer output): <0.01 percent
• Mic/Line/DI Input (at unity gain, electronic output):
  • Warm Disabled: <0.005 percent
  • Warm Enabled: <0.01 percent
• Mic Input (at +60dB gain):
  • Warm Disabled: <0.04 percent
  • Warm Enabled: <0.08 percent

Maximum Levels & Output Impedance

• Mic/Line/DI Max. Input Level (at minimum gain, 1kHz):
  • Warm Disabled: +24dBu
  • Warm Enabled: +18dBu
• Transformer & Electronic Max. Output Level (1kHz): +21dBu
• Output Impedance (1kHz): 50 Ohms

Mute, Filters, & Meters

• Mute Cut-off (1kHz, 0dBu input level, unity gain): -100dB
• Low-Pass Filter: 1kHz to 40kHz, 12dB/Octave
• High-Pass Filter: 10Hz to 400Hz, 12dB/Octave
• Input Meter, Peak Reading Full Wave Rectifier: 31-segment, -20 to +20dBu in 1 and 2dB steps
• Output Meter, Peak Reading Full Wave Rectifier: 31-segment, -20 to +20dBu in 1 and 2dB steps

Power Requirements & Physical Specifications

• Voltage: +16V, -16V, and +48V
• Power Consumption (+/-16V): <200mA per rail, 6.4W total
• Dimensions (H x W x D): 132mm x 76mm x 180mm / 5.2'' x 3'' x 7.1''
• Weight: 1kg / 2.2lbs