The NAP 200, 250, 300 and 500 power amplifiers have been revised and reintroduced for 2015 with output transistors developed during Naim’s work on the Statement project alongside Naim DR (Discrete Regulator) power supply technology.
This new technology is the result of two flagship R&D projects and has been introduced to their core range of two channel power amplifiers significantly boosting sound quality.
Statement Transistor Technology
As part of the Statement project we began development on a new output transistor capable of bettering the previous reference NA007 in terms of sound quality. After over a year of prototyping and listening tests we developed the new NA009 transistor in collaboration with a specialist semi-conductor manufacturer more used to creating military and space exploration grade componentry, such was the attention to detail involved.
The NA009 is a custom Naim design using non-ferrous materials and matched internal dies. Using non-ferrous materials dramatically reduces internal mechanical noise by minimising the vibrations created by high levels of current passing each other through the legs of the transistor.
The NA009s are mounted on ceramic insulators to reduce stray or unwanted capacitance which is a gateway for noise. This new material reduces transistor capacitance by a factor of 9 over the mica counterparts used in the original. The new NAP 250, 300 and 500 DR power amps feature this new transistor technology.
Revisiting the design of these classic amplifiers also gave us the chance to pay attention to every aspect of the design and introduce small changes to layout and componentry where they made a difference in the listening room. One example of this attention to detail is the tiny compliant bends applied in the legs of sound critical resistors which decouple the component from mechanical interference. These small improvements, combined with major technological innovation, lift the musical performance of each power amplifier significantly.
DR Technology Explained
We have long noted the importance of a clean, stable, low-noise power supply to audio performance. Our DR technology, !rst introduced to our range of separate power supplies, is the latest progression of that philosophy. It was adapted and improved for use in Statement, our flagship ampli!cation system, and has now been introduced to our wider range of power amplifiers.
A regulator is an electronic device designed to maintain a constant DC output voltage regardless of fluctuations in supply voltage and in current draw from its output. Naim’s (DR) discrete regulator is a unique in-house design, providing ultra-low noise supply voltage to critical electronics. The new topology, which was benchmarked against various alternatives and refined over a two year period, has proven itself to be inherently low noise and capable of fast recovery to transient current demands.
The new NAP 200 DR features a single Naim DR module which powers the external NAC 202 or 282 preampli!er. This differs from the application of the technology in the NAP 250, 300 and 500 DR where it supplies the entire power amplifier. The circuit is arranged on the main board in a similar way to its application in our flagship Statement amplification system, enabling it to handle the extra current demands. Both versions of this circuit substantially reduce the internal noise floor compared to the older non DR versions (see graph below). This provides the clean and stable voltage reference we know is vital to performance.
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