Single-ended Class-A Performance
The NuForce HAP-100 preamp and headphone amplifier has been designed for the audio enthusiast for whom quality headphone listening is a top priority. The HAP-100's innovative engineering combines features seldom seen at this price point. Most significantly, the HAP-100 offers single-ended Class-A performance, which is considered by many to be the ultimate in high-fidelity design.
"The HAP-100 is quite capable, both as a headphone amp and preamp," notes John Grandberg in his InnerFidelity.com review for July 24, 2013. "In fact I'd say this is among the best amps I've heard in the sub-$1k price class, and probably the best when it comes to the Sennheiser HD 800."
Advanced Volume Control Technology
The HAP-100 incorporates the same volume control technology first developed for NuForce's flagship P-20 preamp. At the unit's core is a switched-resistor ladder network of low-noise, thin-film resistors, one per volume setting, permitting discrete, high-resolution increments of 1dB for each of the HAP-100's one hundred volume steps. In welcome addition to the volume control's fine-adjustment precision, the signal's passage through a single, high-quality resistor at all settings ensures minimal sound degradation.
Zero Negative Feedback Preamplifier Stage
Following this, a pristine, zero negative feedback preamplifier stage delivers vanishingly low levels of distortion, crystalline accuracy and genuine musicality. A true minimalist design, the preamp incorporates an extremely low-noise FET input stage and single high-quality capacitor in the entire signal path. It provides 5dB of gain with zero negative feedback for fatigue-free listening.
The HAP-100 is built on a platform that provides the unit's audio circuits with the purest of DC power. With its toroidal transformer for minimizing magnetic-field interference and capacitor bank's massive energy reserve, the HAP-100's linear power supply delivers explosive dynamics and lightning-fast transients.
For transparency, speed, accuracy, resolution and musicality, along with high style and convenience, the HAP-100 has few equals at anywhere near its price. Its specs are nothing short of stellar: THD+N of less than 0.001% and a dynamic range in excess of 110 dB for the subtlest of musical details against the blackest of backgrounds – without a hint of coloration. The HAP-100's performance, features, style and price are bound to delight.
Input and Output Flexibility
The HAP-100 provides four low-noise, stereo RCA inputs and top-grade relays for input selection. One RCA stereo output offers a full 7.8Vrms to effortlessly drive any amplifier. A front-panel 6.3mm jack is ideal for large, over-ear headphones. Also included are a stylish three-digit display (setting 1 for input selection / settings 2 and 3 for output levels from 00-99) and a full-featured remote control.
"The HAP-100 is quite capable, both as a headphone amp and preamp. It has a special synergy with higher impedance headphones but does well with most others too. In fact I'd say this is among the best amps I've heard in the sub-$1k price class, and probably the best when it comes to the Sennheiser HD 800. It's also far more useful as a preamp compared to the average headphone amp with a single input. There isn't really much to it—no trickery involved, just good honest sound emerging from one of the most silent backgrounds you'll ever experience. If that sounds good to you (and why wouldn't it?), the HAP-100 is definitely worth checking out."
- John Grandberg, InnerFidelity.com, July 24, 2013