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Power amplifiers stereo — Buckeye Amps NCx500 Stereo
Description, images, technical data and specifications
Buckeye Amps NCx500 Stereo
Image source — © Buckeye Amps
The NCx500 Stereo is the 2-channel version of the NCx500 amplifier from Buckeye Amps, a North American maker that builds mono, stereo and multichannel amplifiers around Class D modules from Hypex. Inside the 2-channel chassis sit two Hypex NCx500 amplifier modules fed by a single Hypex SMPS1200A700 switch-mode power supply, and Buckeye adds its own input buffer stage in front of them. The list price at the maker is USD 1,150, and the amplifier carries a 3-year warranty.
Key specs that matter
Per channel the rating at 1 kHz and 1 percent THD reaches 380 W into 8 ohm and 700 W into both 4 and 2 ohm. S/N is 128 dB, frequency response runs from 0 to 75 kHz and THD is 0.0006 percent at 350 W into 4 ohm across 20 Hz to 20 kHz. Output current reaches 28 A per channel, the damping factor is described as ultra high, and power efficiency is given as 93 percent. The all-aluminium case with black powder coat measures 254 mm wide, 330 mm deep and 89 mm high and weighs 3.6 kg.
Engineering and use context
Gain is set in two places. The Hypex module itself runs at 26.8 dB, which on its own asks for about 2.4 Vrms for full output into 4 ohm and 2.5 Vrms into 8 ohm. The Buckeye stage in front offers three switchable settings - High at 24.2 dB, Medium at 19.2 dB and Low at 14.2 dB - so the input level needed for full power into 8 ohm moves from 3.4 Vrms to 6.0 Vrms and then 10.8 Vrms. The purpose, according to the maker, is the lowest noise with any system. That buffer uses a TI OPA1612 op amp, and its supply rails are regulated by TI TPS7A30 and TPS7A49 parts. Power-up and shutdown are muted with a soft start, and faults are reported through the front LED.
Pairing
Signal enters only through Neutrik XLR sockets, although these balanced inputs also accept unbalanced sources through standard adapter cables. The three gain positions let the amplifier suit different sources. Switching on can follow the incoming signal automatically or respond to a 12 V trigger from the preamplifier. Loudspeakers connect through gold-plated 5-way binding posts on the rear panel.
Alternatives
The Buckeye PURIFI 1ET6525SA 2-Channel is a stereo amplifier from the same maker built on second-generation Purifi Eigentakt modules.
Key specs that matter
Per channel the rating at 1 kHz and 1 percent THD reaches 380 W into 8 ohm and 700 W into both 4 and 2 ohm. S/N is 128 dB, frequency response runs from 0 to 75 kHz and THD is 0.0006 percent at 350 W into 4 ohm across 20 Hz to 20 kHz. Output current reaches 28 A per channel, the damping factor is described as ultra high, and power efficiency is given as 93 percent. The all-aluminium case with black powder coat measures 254 mm wide, 330 mm deep and 89 mm high and weighs 3.6 kg.
Engineering and use context
Gain is set in two places. The Hypex module itself runs at 26.8 dB, which on its own asks for about 2.4 Vrms for full output into 4 ohm and 2.5 Vrms into 8 ohm. The Buckeye stage in front offers three switchable settings - High at 24.2 dB, Medium at 19.2 dB and Low at 14.2 dB - so the input level needed for full power into 8 ohm moves from 3.4 Vrms to 6.0 Vrms and then 10.8 Vrms. The purpose, according to the maker, is the lowest noise with any system. That buffer uses a TI OPA1612 op amp, and its supply rails are regulated by TI TPS7A30 and TPS7A49 parts. Power-up and shutdown are muted with a soft start, and faults are reported through the front LED.
Pairing
Signal enters only through Neutrik XLR sockets, although these balanced inputs also accept unbalanced sources through standard adapter cables. The three gain positions let the amplifier suit different sources. Switching on can follow the incoming signal automatically or respond to a 12 V trigger from the preamplifier. Loudspeakers connect through gold-plated 5-way binding posts on the rear panel.
Alternatives
The Buckeye PURIFI 1ET6525SA 2-Channel is a stereo amplifier from the same maker built on second-generation Purifi Eigentakt modules.
Specifications
Model name
NCx500 Stereo
Input sensitivity (mV)
N/A
Input impedance (balanced) (Ω)
N/A
Input impedance (single-ended) (Ω)
N/A
Output impedance (balanced) (Ω)
N/A
Output impedance (single-ended) (Ω)
N/A
Max current (A)
N/A
Output power (8Ω) (W)
380
Output power (4Ω) (W)
700
Gain (dBu)
26.8
Frequency response low +/- 3dB (Hz)
0
Frequency response high +/- 3dB (Hz)
75 000
Signal to Noise Ratio (dB)
128
Total Harmonic Distortion + Noise (0% global feedback) (%)
N/A
Total Harmonic Distortion + Noise (100% global feedback) (%)
0.0006
Max power consumption (W)
N/A
Damping factor
N/A
Dimensions (mm)
254 × 330,2 × 88,9
Weight (kg)
3,63
Official link