Brax X2400

Price & Contact: $1599; 510-548-1168, www.theaudiophile.com
All measurements @ 14 volts unless otherwise specified:
Frequency Response (4-ohm IHF Load, 20 Hz to 20 kHz, 1 kHz Ref.) : +0dB, -0.4dB
L/R channel error max deviation 20 Hz to 20 kHz: N/A
Phase Response (4-ohm IHF Load, 20 Hz to 20 kHz, 1 kHz Ref.) : +8 degrees, -23 degrees
Signal-to-Noise Ratio (Below Rated Output, “A” weighted): -106.8 dB
Distortion at Rated Output @ 1 kHz: 0.01% @ 400 watts x 2
Output Power (resistive) minimum output 20 Hz to 20 kHz @ 1%THD+N, all channels driven into 4 ohms: 116 watts x 4 @ 14 volts, 115 watts x 4 @ 12.8 volts, 91 watts x 4 @ 10.5 volts
Output Power (resistive) minimum output 20 Hz to 20 kHz @ 1%THD+N, all channels driven into 2 ohms: 198 watts x 4 @ 14 volts, 188 watts x 4 @ 12.8 volts, 135 watts x4 @ 10.5 volts
Output Power (4-ohm IHF Reactive Load @ 60 Hz to 1% THD+N): 500 watts
Crosstalk (Referenced to Rated Output, 20 Hz to 20 kHz): -56.5 dB
Damping Factor @ 100 Hz, 2 Ohms: 218
Voltage for Rated Output: 344mV to 6.3 volts
Idle Current Draw: 3 amps
Current Draw @ 1/3 Maximum Power: 73 amps @ 166 watts x 2
Efficiency @ 1/3 Maximum Power : 32%
Power-Up Noise: 9.6 dB SPL
Power-Down Noise: 18.8 dB SPL

		Brax X2400 www.theaudiophile.com
		Power and system flexibility highlight Brax’s new four channel beast.		Brax X2400 Specs Price & Contact: $1599; 510-548-1168, www.theaudiophile.com All measurements @ 14 volts unless otherwise specified: Frequency Response (4-ohm IHF Load, 20 Hz to 20 kHz, 1 kHz Ref.) : +0dB, -0.4dB L/R channel error max deviation 20 Hz to 20 kHz: N/A Phase Response (4-ohm IHF Load, 20 Hz to 20 kHz, 1 kHz Ref.) : +8 degrees, -23 degrees Signal-to-Noise Ratio (Below Rated Output, “A” weighted): -106.8 dB Distortion at Rated Output @ 1 kHz: 0.01% @ 400 watts x 2 Output Power (resistive) minimum output 20 Hz to 20 kHz @ 1%THD+N, all channels driven into 4 ohms: 116 watts x 4 @ 14 volts, 115 watts x 4 @ 12.8 volts, 91 watts x 4 @ 10.5 volts Output Power (resistive) minimum output 20 Hz to 20 kHz @ 1%THD+N, all channels driven into 2 ohms: 198 watts x 4 @ 14 volts, 188 watts x 4 @ 12.8 volts, 135 watts x4 @ 10.5 volts Output Power (4-ohm IHF Reactive Load @ 60 Hz to 1% THD+N): 500 watts Crosstalk (Referenced to Rated Output, 20 Hz to 20 kHz): -56.5 dB Damping Factor @ 100 Hz, 2 Ohms: 218 Voltage for Rated Output: 344mV to 6.3 volts Idle Current Draw: 3 amps Current Draw @ 1/3 Maximum Power: 73 amps @ 166 watts x 2 Efficiency @ 1/3 Maximum Power : 32% Power-Up Noise: 9.6 dB SPL Power-Down Noise: 18.8 dB SPL
		by Brian Smith

		The X2400 is a four-channel amp with power ratings of 100 watts x 4 or 400 watts x 2 into 4 ohms, and 200 watts x 4 into 2-ohm loads. Features include gold plated connections, concealed adjustments, and internal slots that accept optional Circuit Control Cards (CCC). The CCC’s are essentially filter modules which are available with cutoff frequencies ranging from 45 Hz to 4.2 kHz with 6, 12, or 18 dB-per-octave slopes. Each channel of the amp has it’s own CCC slot and there are 23 different cards available, allowing the amp to be configured in nearly any manner imaginable. Performance The X2400 performed quite well during its time on our test bench. Its power ratings appear to be spot on with the slight variation in our test results coming by virtue of our procedure of spec’ing the lowest reading over the entire audio bandwidth. At 1 kHz, the amp meets or exceeds all of its ratings right up until the point at which we lower the supply voltage to 10.5 volts. When driving our reactive loads, the X2400 provided a healthy bonus, producing 500 watts x 2 into the 4-ohm loads. Noise performance was equally impressive, with almost -107 dB of signal-to-noise and relatively low turn-on/off noises of 9.6 and 18.8 dB SPL. This is especially impressive considering that there are four relays on the amp’s circuit board, which appear to be in the signal path. If you have relays that switch quietly, you either spent some bucks or got seriously lucky. The X2400 lost a single capacitor in its power supply just as the test ended. German engineering certainly gets a lot of lip service, but in my experience, all amplifier smoke smells pretty much the same, regardless of nationality. However, perhaps the fact that the amp continued to function is a testament to those Teutonic thinkers after all. I even went back and ran a few of the tests over again and everything fell right into spec. I’ve let the magic smoke out of many, many amplifiers in my time, but the X2400 is definitely the first that continued to kick major ass. (Realize that this extreme test is one that you would almost never encounter in the real world and that Brian was quite impressed with the Brax amplifier’s ability to not only continue to play, but to continue to meet spec. Couple this with Brax’s lifetime dealer installed warranty, and you should have no fear — Ed.) Connections & Adjustments Connections to the X2400 include RCA inputs, internal CCC slots, and captive-style terminal blocks for all power and speaker connections. Power and ground connections accept up to 4-gauge bare wire, while speaker connections accept up to 10-gauge. Adjustments include an input sensitivity control for each channel and a stereo/mono switch for each pair of channels. Installation The X2400 should be relatively easy to work with so long as you get the CCC’s and stereo/bridge switches configured correctly before screwing the amp down. Both the switches and the CCC access panel are located on the bottom of the amp. It’s much the same with the input sensitivity controls, which are located under the nameplate located on the top of the amp’s heat sink. Four hex-head screws secure this nameplate, so it’s highly unlikely that an “accident” will ever occur. The X2400 has a massive, attractive heat sink with a fair amount of surface area. Its only drawback is that the majority of the surface area (i.e., the fins) is located along the sides of the chassis, requiring that the amp be mounted vertically for optimum cooling. Otherwise, the X2400 appears to be a well thought out design with overall construction not unlike that of a Sherman tank....or would that be a Panzer?