Allegri Preamplifier

• Features
• Specification
• Notes on design
• Reviews

• • Fractal-Wire ™, results in the most accurate, uncoloured and open-sounding preamplifier possible – with astonishing transparency and resolution of fine detail.
  
  
  
  • Autotransformer Passive Stereo Preamplifier A high fidelity line level controller that selects 6 RCA phono inputs, adjusts gain and provides 2 RCA phono outputs.
  
  
  
  • Purely passive device eliminates signal degradation caused by mains-born noise.
  
  
  
  • 6 inputs, 2 outputs.
  
  
  
  • 24 position volume control provides gain change from +4dB to -60 dB.
  
  
  
  • Mute switch to select off at any volume setting.
  
  
  
  • DC coupled with no capacitor in the signal path for ultimate sound quality.

• Frequency response:	8Hz-100kHz +/- 0.1dB
  Maximum signal level:	4V RMS 8Hz; 10V RMS 20Hz
  Maximum DC offset :	5mV. (For undistorted 8Hz)
  Distortion:	Less than 0.01% at 400Hz, 10V (2nd and 3rd harmonic only)
  Input impedance is dependent upon the load impedance and gain setting. So, with a power amplifier having 20kohm input impedance (typical)
  Impedance:	At 0dB, input impedance is 20kohm At -10dB (normal listening) input impedance is 200k
  Inputs:	6 pairs RCA phono sockets (gold plated)
  Outputs:	2 pairs RCA phono sockets (gold plated)
  Width:	127mm (5in)
  Height:	45mm (1.8in)
  Depth:	305mm (12in)
  Weight:	1.5kg (3.3lb)

• After 40 years of research encompassing all styles of amplification - including discrete transistor (bipolar & FET), integrated circuit, valve (tube) and digital - we have found that all active implementations inevitably cause a slight veiling, noise and detail loss.
  
  Furthermore all volume controls - potentiometers (carbon, plastic film and Cermet), switched resistor, optical and digital - similarly cause varying degrees of veiling and detail loss.
  
  Conventional transformer volume controls are excellent. However it is very difficult to achieve a flat frequency response at all volume settings due to the stray capacitance reacting with the unterminated coil sections.
  
  The claim that transformer controls allow for balanced operation is only partly true as the circuit cannot be fully balanced due to asymmetry in the configuration. Allegri is special because it uses an autotransformer for volume instead of a potentiometer. A potentiometer is like an automatic car where the accelerator is on full and speed is regulated by the brake, an autotransformer is more like a manual car where speed is controlled by an accelerator. Also, the use of Fractal-Wire™ reduces losses to virtually zero.
• Hi Fi Choice - Jason Kennedy

  "There is something about hearing the extra layers of sound and effects in a complex mix. If you want to hear more of the nuance and phasing in your favourite records, whatever format they may be in, then this is something of a bargain…. It imbues the music with extra energy that some consider to be lacking in passive devices, making this component very engaging” .
  
  
  
  Hi Fi critic - Martin Colloms

  Martin Colloms for Hi Fi critic gives the Allegri a massive 235: "The listeners were immediately aware of the lack of electronic hash, glare, hardness and artificiality. Instead we heard near magical transparency, exceptional bandwidth, tight control, fine clarity, wide dynamic range, excellent pace and timing, and deep, wide sound stages. Scores can become a little crazy when one encounters components that redefine sound quality, but I have to give this control unit a massive 235 under good source and load conditions".