We make some very good tube preamps, and we are confident that you enjoy using them. But the ADL 600 is at another level. Rumor has it that some people are willing to sell their left eyeball to get one. And while we don't accept eyeballs as payment, we do agree that the ADL 600 is the finest tube preamp money can buy. Not the finest for the price. The finest—period.

Designed with famed tube-circuit designer Anthony DeMaria, the ADL 600 employs a distinctive Class A, discrete design with three top-grade vacuum tubes per channel, operating with ±300V power rails for maximum headroom and superb tone. The dual-transformer design also ensures low-noise operation, with maximum common-mode rejection.

We use only the finest components, including switched attenuators, analog VU and LED meters, and custom-designed, proprietary transformers. There are no op-amps or ICs in the signal path. We went high-end all the way, right down to the last polypropylene film capacitor.

The result is an ultra-low-noise tube preamp with a big, warm, smooth, clear, distinctive sound. It produces big, smooth, and articulate vocals; deep and tight bass guitars; and rich, full mixes. It makes virtually anything you run through it sound better.

MPN: ADL600

2 input channels, each with:

• Mic, line, and instrument inputs
  
• High-voltage, Class A, dual-transformer, vacuum-tube preamp
  
• 3 military-grade vacuum tubes
  vInput-source select
  
• Variable mic-input impedance (150, 300, 900, 1,500Ω)
  
• Variable high-pass filter (40, 80, 120 Hz)
  
• 8-position Gain switch
  
• Variable Trim adjustment for final stage
  
• 48V phantom power
  
• -20 dB pad
  
• Polarity-reverse switch
  
• Backlit VU meter (output level) with -6 dB switch (for metering hot signals)
  
• > 73 dB of gain
  
  Input/Output
  
• 2 unbalanced ¼" instrument inputs (front panel)
  
• 2 transformer-balanced XLR line inputs
  
• 2 transformer-balanced XLR mic inputs
  
• 2 transformer-balanced XLR line outputs
  
  Physical
  
• 2U 19" rack-mountable, rugged steel chassis
  
• Internal power supply with standard IEC connector
  
• Chassis-ground link connectors (lift chassis ground)
  
  Input Impedance
  
• Microphone: Selectable, 150/300/900/1500Ω
  
• Balanced Line: 2 kΩ
  
• Instrument: 100 kΩ
  
  Maximum Input Level
  
• Microphone (1500Ω, +20 dB Pad out): +5 dBu
  
• Microphone (1500Ω, +20 dB Pad in): +25 dBu
  
• Balanced Line: +30 dBu
  
• Instrument: +30 dBu
  
  Gain Range
  
• Microphone (1500Ω, +20 dB Pad out): 18 dB to 72 dB
  
• Balanced Line: -12 dB to 40 dB
  
• Instrument: -5 dB to 42 dB
  
  Performance
  
• Noise Floor (all inputs, minimum gain): -95 dBu (A-weighted)
  
• Microphone Equivalent Input Noise (EIN): -125 dBu (A-weighted)
  
• Frequency Response: l: +23 dBu (@ 0.5%THD+N)
  
• Output Impedance: 600Ω
  
• Tube Complement (per channel): 1-12AT7A, 2-6922
  
  Power
  
• Internal supply, standard IEC connector: 115 or 230 VAC / 100W
  
  Physical
  
• Dimensions: 2U rackmount
  
• Height: 3.5" (88.9 mm)
  
• Depth: 17" (431.8 mm)
  
• Width: 19" (482.6 mm)
  
• Weight: 28 lb. (12.7 kg)