Classe Audio Delta CP-700

The CP-700 is fully balanced, with a signal/noise ratio of 100dB, 20Hz-500kHz. "A lot of attention was paid to noise reduction by optimizing such things as parts selection, power routing, and balanced circuitry," said Nauber. "But when balanced circuits are carefully designed to create better common-mode rejection of noise, it also leads to better dynamic performance." The CP-700's power supply is housed in a completely separate chassis. "This allowed for a greater degree of isolation with less cumbersome shielding," said Nauber. "There is one transformer with five separate secondary windings for the preamp power supplies (audio circuits and control), and a separate transformer for the sensor and protection circuits." A number of subtle engineering details in the power-regulation circuitry are designed to result in cleaner, more detailed sound. The CP-700's total harmonic distortion (THD) plus noise is rated at an impressive 0.0012%. Additional insightful engineering is found in the two channels separate volume controls. "We use what might be called a double cross-balanced approach in the gain stages," said Nauber. "There are actually six signal paths per channel, with inverting and non-inverting balanced circuits and a single-ended circuit." The reported result is channel separation greater than 110dB. To further reduce noise, when a source is selected, all other sources are completely disconnected from the audio circuits.

Frequency response 20 Hz - 200kHz +/- 0.1dB Distortion (THD + noise) 0.0012% Maximum input voltage (single-ended) 5Vrms Maximum input voltage (balanced) 10Vrms Maximum output voltage (single-ended) 10Vrms Maximum output voltage (balanced) 20Vrms Gain range -86dB to +14dB Input Impedance (single ended) 100kO Input Impedance (balanced) 200kO Output Impedance 100O Maximum Input to Noise Floor 120dB Channel separation 130dB at 1kHz Crosstalk (any input to any output) better than -120dB @ 1kHz Rated power consumption 42W Idle power consumption 29W Overall dimensions (preamplifier) Width: 17.5" (445mm) Depth: 16.5" (419mm) Height: 4.75" (121mm) Overall dimensions (power supply) Width: 5" (127mm) Depth: 12" (305mm) Height: 5.5" (140mm) Net weight (preamplifier) 23lbs (10.5kg) Net weight (power supply) 10lbs (4.6kg) Shipping weight 45lbs (20.5kg)