Naim NAP 250 Power Amplifier

Class A Service 05/04/2014

Re-Cap and service, align and test. Fit listed parts
2 x 15,000uf @ 63 volt Capacitor
6 x 10uf @ 35 volt Capacitor
4 x 47uf @ 40 volt Capacitor
4 x 10uf @ 63 volt Capacitor
4 x zener diode
4 x 3K3 1w resistor
4 x cabinet foot and screw
8 x Torx m4 x 8 csk bolt

***************************************************************

Here we have a classic ‘Olive’ finish power amplifier from British specialist NAIM Audio. A very nice example of the amazing NAP 250, produced in 1992, and serviced by Class A in 2014 – service documents supplied. It comes supplied in its original packaging, with manual, mains cable, 4-pin-DIN to XLR cable and our usual three month warranty.
The NAP 250 must be one of the longest running power amplifiers still in production today, their website quotes 1975 as its year of introduction. In all that time, the NAP 250 has had three makeovers at long intervals, and only one major internal upgrade, which happened in 2015 and warranted a slight name change to the NAP 250 DR. It started out life with the classic “chrome bumper” look, then in the late eighties came the “Olive” look that we have here before it took on Naim’s “Classic” look.
Naim say….
The NAP 250 is Naim’s uniquely evolved and refined classic amplifier, that uses a very large high quality toroidal transformers. Power transformer design is a very specialised field, and our transformers are the result of many years of closely co-operative development with our manufacturers. The 250 has four regulated power supplies each of which is rated at 40 volts and able to deliver more than 15 amps. The highest quality components are used throughout, with great attention to detail construction. Our exceptionally fast and robust output transistors are made for us to our own specifications. Our standard protection circuitry is augmented by a power supply trip which operates if 18 amps is demanded for more than 10 micro-seconds. Heatsink temperature is monitored by a thermal cut-out which resets automatically.
Specifications:
Power Output: 70 W per channel into 8Ω
Transient: 400 VA
Voltage Gain: +29 dB
Input Impedance: 22 KΩ
Frequency Response: -3 dB at 3 Hz & 40 kHz
Mains Supply: 100 V, 110 V, 120 V, 200 V, 220 V or 240 V, 50 or 60 Hz
Dimensions: 460 (W) x 300 (D) x 76 (H) mm

For a little back story about the NAP 250 from Hi-Fi Choice magazine please click here