Stereo tube microphone preamplifier

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It is hard to explain how this stereo tube microphone-line preamplifier “does not” sound, since is less prone to classic tube colouration. Optimized towards capturing the subtlest detail of music and ambience, with it's entirely balanced circuitry, the SMP-2 is able to deliver extremely wide dynamic range in your stereo works, intended for demanding acoustic recordings. Due to our “high linearity” design philosophy, the absence of the Lo-Cut facility allows the highest phase linearity throughout the entire audio band, especially at the very lowest frequencies, and thanks to its full symmetric balanced topology (the two rails work together in reversed phase in a Push-Pull configuration), the circuit is able to cancel out distortion and non linearity, also significantly extending the amplifier headroom, a very important feature when handling high dynamic material such as vocals.

A Microphone-Line preamplifier intended for stereophonic miking techniques: coincident stereophony (X-Y, M-S, Blumlein, Stereosonic), spaced pairs (A-B, NOS, OSS), etc.

The components used are all selected with the strictest tolerance, and tested by ear. All tube audio path circuitry.


  • Twin channel microphone preamplifier
  • Stereo or Dual Mono operation
  • Intended for Stereo Miking Techniques
  • Minimum signal path preserving audio integrity
  • All valve-based audio circuitry, totally analog processing
  • Inductively filtered plates supply, fully filtered and regulated heaters supply for lowest noise
  • Entirely balanced signal route with paralleled Class A differential stages
  • Absence of capacitors and resistors in the audio path
  • No negative feedback
  • Fixed gain stages for less audio coloration and total repeatability
  • 11-step gain control through a custom multi-tap audio transformer
  • Linear frequency and phase response over the entire audio range and beyond

Technical specifications

  • Frequency response (+0/-3dB): 15Hz — 45kHz
  • C.M.R.R., 1kHz: ≥60dB
  • Signal/noise ratio at 20dB, 22Hz/22KHz, 600Ω terminated: ≥98dB
  • Maximum output level for 1% THD+Noise: +18dBm
  • Maximum gain: 55dB (±3dB)
  • Input impedance: 1.2kΩ
  • Output impedance: 600Ω
  • Chassis: rackmount, 2 units
  • Dimensions (WxHxD) inches: 19 x 3.465 x 16.14
  • Net weight: 25.13 lbs (11.4 kg)


How to buy?

Our products are handcrafted in Italy and are available through Direct Sale between us and the end user.

Optimizing costs

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