First Watt F7 Power Amplifier

First Watt F7 Power Amplifier

For those that don’t know Nelson Pass the FIRST WATT F7 is a power amplifier from his limited availability range rather than the more commercially available PASS LABS.

Why do we prefer FIRST WATT? Well, there’s something personal in these designs which just floats our boat. Plus the limited availability makes them collectable and something to own, treasure and enjoy.

Each FIRST WATT amplifier has a limited run and then they are gone. This can be down to availability of parts or just Nelson experimenting and improving on what he has produced previously.

Either way, like many other enthusiasts, we love what Nelson does and we’re very happy to share that experience with you.

Of the FIRST WATT F7 power amplifier, Nelson says:

“The F7 is a very unique amplifier, a two-stage push-pull JFET/MOSFET topology with fewer parts than any First Watt amplifier to date, and incorporating a very interesting balance of very low negative voltage current feedback to give an astonishing measure of control over reactive loudspeaker loads.”

Nominal Specifications:

(Measured at 120 V AC and an 8 ohm load)

Distortion @ 1 watt: 0.05%Input Impedance: 10 Kohm

Gain: 14.5 dB

Input Sensitivity (1 watt): 0.53 V

Input Sensitivity (max output): 2.7 V

Damping Factor: >100

Output power 8 ohms: 20 watts @ 2% THD, 1KHz

Output power 4 ohms: 30 watts @ 3% THD, 1KHz

Class A envelope: 40 watts peak @ 4 ohms

Frequency response: DC to -3 dB @ 100 KHz

Noise: 100 uV unweighted, 20-20 KHz

Power consumption: 170 watts

Fuse: 3AG slow blow type – 1.25 Amp for 240 VAC

Warranty: Parts and labour for 3 years, not covering shipping costs or consequential damages.

Finish: Silver