Усилители мощности стерео — Parasound ZC ZAmp V0.3

The ZC ZAmp v3 is a small stereo power amp belonging to Parasound's Z Custom series, housed in a half-width chassis one rack unit high. It uses fully discrete circuitry with a toroidal power transformer, and Parasound lists it at USD 450 and grants one year of parts and labour cover.

Key specs that matter

Continuous output is 45 W RMS per channel into 8 ohm and 60 W RMS per channel into 4 ohm, measured from 20 Hz to 20 kHz with both channels driven. In bridged mono mode the amplifier delivers 90 W RMS into an 8 ohm minimum load. Peak current capacity is 12 A per channel. Frequency response extends from 5 Hz to 100 kHz, +0/-3 dB. Total harmonic distortion stays below 0.07% at full power and below 0.02% at typical levels, intermodulation stays below 0.05%, and dynamic headroom is 1.5 dB. Noise is 116 dB below output IHF A-weighted, measured with a shorted input. Crosstalk between channels is 80 dB at 1 kHz and 60 dB at 20 kHz. Input impedance is 33 kOhm, and Parasound gives input sensitivity as 600 mV, and states that 1.5 V drives it to full output.

Engineering and use context

The case is 216 mm wide, 44 mm high and 254 mm deep, growing to 51 mm in height with its feet, and the net weight is 3.2 kg. Parasound describes it as a low heat design. The amplifier switches on automatically from a 9-12 V trigger, and it can also start when it senses an audio signal. Indicators on the front report AC power and the operating status of each channel. The front panel also carries a headphone socket. At the rear are gold-plated RCA input jacks, a pair of looping line output jacks and 5-way speaker terminals. The looping outputs forward the incoming signal to another amp, an arrangement Parasound suggests for extra zones or for bi-amping. A rack mount kit is sold separately for installation in equipment racks.

Pairing

Without its own volume control the ZAmp v3 is driven by an external preamp, a streamer whose output level can be varied, or a computer audio interface, and its small footprint suits desktop systems as well as multi-room installations. The Z Custom series also includes the ZPre3 preamplifier in the same half-width format, which offers five analogue inputs including a front Aux, variable and fixed outputs with a dedicated subwoofer output, a home theater bypass and Control4-ready two-way RS-232 control.

Alternatives

The Parasound NC 275v2 is a bigger NewClassic stereo power amp, a full-width 1U Class AB unit with 20 A peak current per channel.