18k Preamplifier

The 18K is a line level preamplifier engineered and handcrafted in the Aragon tradition. It features six inputs, 2 preamp outputs to facilitate bi-amping, and 2 tape outputs for maximum flexibility. Separate listen and record source selection switches allow for listening to one source while taping from another.

The new circuit is fully discrete Class A, with a direct coupled output. It has a fraction of the negative feedback found in the typical preamplifier, and extremely low output impedance. The large circuit board ground plane assures very quiet operation. The 18K goes beyond what others define as "bypass mode," with only a single switch contact in the signal path. The stable gain stage requires no output capacitors. When combined with the direct coupled input stage of the 2004MKII or 4004MKII amplifier, it yields a direct coupled system, capable of reproducing bass well below 20Hz.

The 18K's power supply is housed in a separate chassis designated for the IPS, or Isolated Power Supply. The IPS rectifies the AC power input to DC, then regulates the output with discrete transistors, outboard of the 18K's sensitive high gain circuitry. This is equivalent to using batteries to power the 18K, thereby ensuring the quietest possible operation. To guarantee operational stability, the total power supply capacity is over 20,000 microfarads. The preamplifier's main chassis incorporates dual mono DC supply rails. Regulation for each channel is provided by discrete transistors, rather than integrated circuits as you would find in other preamps and inexpensive receivers. This allows us to custom design and optimize the power supply to the signal path circuitry.