Preamplifiers — Ladder Chopin II

The Chopin II from Ladder is a line-level preamplifier for systems that run on balanced connections. Its circuit is fully balanced, fully discrete and runs in pure Class A, with discrete field-effect transistors handling the output amplification. Ladder offers it in black or silver, and the US price is USD 1,545.

Key specs that matter

Sources connect through two stereo XLR inputs and one stereo RCA input, while a single XLR output pair and a single RCA output pair carry the signal out. The inputs present 60 kohm on XLR and 12.2 kohm on RCA, while the outputs measure 400 ohm balanced and 200 ohm single-ended. Gain is unity at 0 dB, and the maximum output reaches 4.0 Vrms on XLR and 2.0 Vrms on RCA. Frequency response runs from 10 Hz to 80 kHz within 0.3 dB. The maker quotes THD+N below 0.0006 percent, 120 dB signal-to-noise ratio, dynamic range above 121 dB and stereo crosstalk of -110 dB. The aluminium alloy chassis measures 320 x 330 x 60 mm and weighs 6.5 kg.

Engineering and use context

A 60-step relay attenuator sets the volume under microprocessor control, with no potentiometer in the signal path. The resistors in this network are precision-matched to keep the left and right channels tracking together across the range. Power comes from a 65 W toroidal transformer wound with pure copper, followed by eight independently regulated supplies that feed separate parts of the circuit, and a bank of ERSE capacitors supports the supply. The mains input accepts 100 to 240 V at 50 or 60 Hz, so the unit works in any region without internal changes. Consumption is about 1 W in standby and 20 W in operation. The supplied remote control covers power, input selection, mute and volume. Because the gain is fixed at unity, the Chopin II switches and attenuates sources without adding level, which suits setups where the source already delivers a full-scale output.

Pairing

Digital sources fitted with XLR sockets connect most directly, since two of the three inputs are XLR, and a phono stage or other single-ended source can take the RCA input. On the output side the fully balanced path suits a balanced power amplifier, and the RCA pair can feed a single-ended amplifier or an active subwoofer. Owners of a sensitive power amplifier get finer control from the 60 relay steps at low listening levels.

Alternatives

The Ladder Bach II is another fully balanced Class A preamplifier with a 60-step relay attenuator, housed in a 336 x 304 x 66 mm chassis.