Усилители мощности стерео — Gato Audio DPA-2506

Built in Denmark by Gato Audio, the DPA-2506 is a Class-D power amplifier with six channels, rated at 250 W per channel into 8 ohms and 500 W into 4 ohms. Each pair of channels can be bridged, so the same unit can serve a multichannel home theater, an active loudspeaker system or bi-amped stereo speakers.

Key specs that matter

In bridged operation a pair of channels delivers 900 W into 8 ohms and 1050 W into 4 ohms. Mixed configurations are possible too - three bridged channels, two bridged plus two single channels, or one bridged plus four single. Frequency response is 20 Hz to 20 kHz within 0.5 dB and 2 Hz to 70 kHz within 3 dB, harmonic distortion is under 0.01% at full rated output, and noise is more than 110 dB down. Input impedance is 20 kOhm RCA or 40 kOhm balanced, voltage gain is 26 dB, and the recommended speaker load is 4 to 16 ohms. The case is 325 x 105 x 420 mm and weighs 10 kg.

Engineering and use context

Six separate Class-D output stages each have a dedicated switch mode power supply. They are based on International Rectifier technology, optimised by Gato Audio with a precision oscillator running at high frequency and a PWM modulator. Each stage uses a pair of precision MOS-FET switching transistors with very low on-resistance to keep switching losses down, and the output filters combine polypropylene capacitors with low DCR coils to turn the PWM signal back into an analogue waveform. Mains supply is 115 or 230 V, and consumption is under 1 W in standby, 35 W at idle and 2000 W at most. An 8 AT sand-filled fuse is fitted. The channels are organised in three sections of two, channels 1-2, 3-4 and 5-6, and each section is switched between single-ended and bridge mode on the rear panel while the amplifier is off. Each channel takes either its XLR or its RCA input, never both at once. Internal micro switches, set by a technician, change gain per channel by -2, +2.5 or +6 dB from the factory setting, which matches the DIA-250 and DIA-400, and bridged channels must share the same setting.

Pairing

Three pairs of gold-plated XLR inputs and three pairs of RCA inputs feed six pairs of safety banana outputs, and a mini jack trigger allows switching on together with the source. Gato Audio names the PRD-3 preamp and DAC as an ideal match, and the DIA-250 and DIA-400 integrated amplifiers can hand extra channels over to it.

Alternatives

The Gato Audio DPA-4004 is a four-channel sibling offering 400 W per channel into 8 ohms and 1400 W per bridged pair.