The NuForce P-9 Preamplifier

NuForce has been releasing one well received product after another, since their inception. Well, Jason Lim and company have done it again with the P-9 preamp. Since NuForce intended the P-9 to be their flagship preamp, Demian Martin was brought in as the chief designer of the P-9. Demian Martin has a long history in the audio industry. As the co-founder and Director of Engineering of Spectral Audio, he was responsible for the design and engineering of many of Spectral�s now classic designs such as the DMC-10 preamplifier.

Many of you already know that many of Spectral�s products set new industry standards at the time. The P-9 is a two box unit, (not very unusual for high end line stages these days), that is slightly larger than the company�s 9-SE power amps. After becoming very familiar with the NuForce power amplifiers, it was very anxious to audition their latest top of the line pre-amp. As you will see, this is a very special component in its own right.

Background
According to the manufacturer, the P-9 is designed to be a low noise high performance component.

The two box design goes further than simply housing the noisy power supply in a separate enclosure. Since the P-9 uses three separate power supplies, all of them along with the microprocessor control logic are contained in the control box.

All of the analog circuitry is contained in the analog box. In order to achieve a very high degree of isolation, the amp modules operate within heavy copper shields with internal thermal insulation. Analog signals only pass through the analog box. The P-9 features an all discrete precision amplifier module employing ultra low noise, monolithic dual JFETs, specially selected MOS FETs and very flat hEE bipolar transistors in a dual cascade design with a driven shield to reduce capacitive loading on the final voltage amp.

All of these features combine to give the P-9 a S/N ratio in excess of 100db and a dynamic range in excess of 120 db. Essentially, these circuits are as complicated as they are unique. A number of peripheral circuits are used to stabilize the main circuit. The result is a component that is very stable and quiet.

Set Up
The two boxes weigh in at a combined weight of 13 pounds and measure 1.76�H X 8.5�W X 16�D. As with all NuForce gear, they make very modest demands on valuable shelf space. Installing the preamp is quite easy but while it is extremely difficult for the average audiophile to do, it is advisable to read the owners manual first. It is most important to connect the 15-pin DC and control cable between the two boxes before powering up the unit.

Should you wish to place the boxes further apart than the cable will allow, you must obtain a longer cable from NuForce. The control cable may look like a typical VGA cable used for computer monitors however, there is a significant difference. The P-9 uses all 15 pins in the cable; since all of the pins in a typical computer cable are not connected, they will not work with the P-9.

The P-9 must be fully powered down while connecting source components. Once your connections are made, then you should connect the power cord. It should mention that the supplied power cord is not a throw away. It may not look like much but, it is in fact a high quality power cord. Experiment with other cords if you will but hang on to the supplied cord until you are sure another one actually makes a sonic improvement.