Chameleon Labs 581

Stock Item, Usually Ships Same or Next Business Day

Stock Item: Ships from our shelf quickly in almost all cases when ordered before our ship cutoff times.

Direct Ship: Non-stock item, but normally ships quickly from the manufacturer or alternate warehouse.

Built To Order: Item is custom built per the options chosen and quickly shipped out upon completion.

More On The Way: The manufacturer is experiencing delays, but we'll ship quickly upon arrival.

New Item: We have this on order, the manufacturer hasn't shipped but you'll be in line upon arrival.

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ZenPro Mod (Optional)

  • Mic Input Transformer Upgraded to Carnhill
  • Adds $140 to the price

Your Model 581 microphone preamplifier card has a transformer balanced input with a gain range of +25dB to +80dB. The Model 581 has been carefully constructed and individually tested for quality. It utilizes class ‘AB’ circuitry. This unit is made with 100% discrete components and was fabricated to precisely match vintage counterparts manufactured in the early 70’s. The Chameleon Labs Model 581 is based on high audio performance design techniques. By employing classic circuit design, polystyrene capacitors, hand selected components and custom wound transformers, Chameleon Labs ensures that the Model 581 will exhibit classic audio sound. It is also designed to comply with any 500 series powered chassis approved by the API® VPR Alliance. Your Model 581 represents a dramatic breakthrough in delivering
vintage audio performance at an affordable price.


  • API 500 Series Compatible Card
  • Fully Balanced Mic Input Transformer
  • Hi-Z Direct Instrument Input (TRS)
  • Fully Transformer Balanced Output
  • Discrete Class AB Electronic Topology
  • 48 V Phantom Mic Power
  • 12 Position Mic Gain Rotary Switch
  • Selectable 300Ω or 1200Ω Mic Input Impedance
  • Power, Overload, Signal, and Peak LEDS
  • Reverse Phase Switch

Technical Specifications

  • Microphone Input Impedance: 300Ω or 1,200Ω
  • Microphone Amplifier Gain: +25 dB to +80 dB in 5 dB steps.
  • Output Impedance: 100Ω
  • Noise: -115.5 dB
  • Maximum Output: +26 dB into 600Ω
  • Frequency Response: 20Hz – 20 kHz +/- 1 dB.
  • Dimensions and Weight
  • Weight: 2 pound 8 ounces
  • Dimensions: Width – 1.5”, Height – 5.25”
  • Depth to Rear of Mounting Surface: 5.938” =/- 0.02”
  • Power Requirements: +/- 16 V @ ≤ 130 ma, +48 V @ 5 ma

Our ONE WITH EVERYTHING ZEN WARRANTY extends the standard manufacturer warranty by one year, see our ZEN WARRANTY page for details.

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