Chord Electronics SPM4000 Power Amplifier – Silver

Here we have an SPM4000 power amplifier from specialist British electronics company Chord, in the popular silver finish. It is in very good overall condition, with one small blemishes on the left hand side – please see photographs. It comes in its original factory packaging with manual, mains cable and our regular three month warranty.
Chord Say….
Much of what Chord has achieved is the result of using innovative, leading edge technology. For example, we believe that we are unique in using the technique of ‘dynamic coupling’ of the power supply rails. Whatever transient demand is presented to the amplifier stages, the positive and negative rails remain in perfect equilibrium, with each compensating for the demands made on the other. This means that power delivery is always balanced and free from ground loop modulation distortion.
This, combined with enormous reserves of instantly delivered, precisely controlled power is what makes the SPM 4000 sound so effortless. The power supply rails operate nominally at ± 110 volts, well above that which most amplifiers can accommodate. This and other advanced techniques enables the ultra high frequency low ESR power supply to store a great deal more energy far more efficiently. Clipping is virtually impossible. Furthermore, compared to other amplifiers of a similar power rating the SPM 4000 weighs in at a mere 50Kg. Another new technique is used to protect the amplifier against overload, internal and external short circuits. The output signal path is totally free of any fuses or sound-degrading resistive components often employed for overload sensing. The SPM 4000 is designed to surpass the highest European safety and electromagnetic interference standards.
The amplifier sections are also highly sophisticated designs that make the most of the best high voltage, lateral structure MOSFETs available, 32 x 150 watt devices per channel. Combining the subtlety and musicality of a good valve design with the punch and accuracy of ‘state of the art’ solid state products. The result is a ‘sliding bias’ class A/B design with all drive circuitry operating in class A. At usual listening levels, most of the music will be reproduced in class A. Chord’s no-compromise design philosophy means there is no better built amplifier. Individually hand-crafted, it is constructed to aerospace standards from the circuit boards up.
Specifications:
Output Power: 2 x 490 W rms per channel @ 0.05% distortion into 8 Ω; 2 x 810 W rms per channel @ 0.05% distortion into 4 Ω
Dynamic Headroom: 625 W rms per channel into 8 Ω; 1250 W rms per channel into 4 Ω
Frequency Response: – 1 dB, 0.2 Hz to 41 kHz (8 ohms); – 3 dB, 0.1 Hz to 89 kHz
Frequency Response: – 1 dB, 0.2 Hz to 41 kHz (4 ohms); – 3 dB, 0.1 Hz to 79 kHz
Signal To Noise Ratio: Better than – 103 dB, ‘A’ weighted two thirds power
Channel Separation: Better than 95 dB
Pre-Amplifier: 2 x gold-plated fully balanced
Input Connections: XLR sockets. 2 x gold-plated RCA phono sockets, unbalanced
Input Impedance: 100 kΩ. Unbalanced or Balanced
Input Capacitance: < 30 pf
Output Impedance: 0.01Ω
Output Inductance: 1.6 µH
Output Connections: 8 x gold-plated WBT binding posts
Slew Rate: 70 V per µS, 1 kHz 20 V square wave
Gain: 30 dB
Stability: Unconditional
Dimensions: 480 (W) x 355 (D) x 320 (H) mm
Weight: 40.0 kg