Circle Labs A200

The A200 is now Circle Labs' flagship integrated amplifier, featuring proprietary designs. A minimalist preamplifier based on the ECC88 tube is combined with a Circle Power technology transistor amplifier. The power stage provides adequate dynamics and good drive of most loudspeakers. The amplifier is equipped with a remote control.

The A200 is a 120 W/8 ohm and 200 W/4 ohm design featuring a symmetrical Xlr input, three pairs of Rca line inputs and a pre out. The amplifier is built based on the topology - volume control - SE tube preamplifier - power amplifier with Circle Power technology. Volume control is implemented by a ladder of resistors from the renowned Khozmo company. The resistors, with a tolerance of 0.1%, are switched in it by high-end relays, which guarantees the highest possible precision and durability unavailable for traditional potentiometers. This control is equipped with a remote control. The single-stage preamplifier is built using a tube from the ECC88 family operating with fixed polarity. This solution allows the use of the smallest possible number of passive components. The circuit is built using a single tube, a resistor and a top-quality solid copper film signal capacitor, which directly translates into a neutral sound and dynamic command. This section uses separate tubes for each channel and stabilized power supplies with polypropylene capacitors. The Circle Power amplifier is a proprietary development by Circle Labs. Its sound is often described as "a combination of the best features of tube and solid-state designs." The stage uses an asymmetrical input stage and current-controlled bipolar final transistors. This solution combines the detail and precision characteristic of asymmetrical circuits with the efficiency and dynamics of symmetrical circuits. The low output impedance of the final stage, and thus the high damping factor, ensures adequate dynamics and good drive of most loudspeakers on the market. The power amplifiers are built in dual-mono technology with separate toroidal transformers and power supplies with a total capacitor capacity of 200,000 µF.