Scott 399 (1969)

Name: Scott 399
Brand: Scott

The Scott 399 is a classic solid-state stereo amplifier introduced in 1969 by H.H. Scott, Inc., a company renowned for its commitment to high-fidelity audio reproduction. Though not as widely documented as some of its contemporaries, the Scott 399 occupies a respected place among vintage audio enthusiasts for its technical sophistication, conservative design philosophy, and exceptional build quality. As part of Scott’s push into the solid-state era, the 399 represents a transitional moment in audio engineering—bridging the gap between the warmth of tube amplification and the precision of transistorized circuitry.

Design and Engineering Philosophy

H.H. Scott, Inc. was founded by Hermon Hosmer Scott, an MIT-trained engineer who pioneered the concept of the "communications receiver" and emphasized measurable performance in audio equipment. The company’s products were known for their adherence to scientific design principles, low distortion, and wide frequency response. The Scott 399 continues this tradition, embodying the company’s belief that high fidelity should be both technically accurate and musically satisfying.

The 399 is a dual-mono, two-channel power amplifier designed for stereo operation. It delivers 35 watts per channel into an 8-ohm load, with less than 0.1% total harmonic distortion (THD) across its operating range. This power output was substantial for its time, especially considering the efficiency of speakers available in the late 1960s. The amplifier operates in class AB, a common and efficient configuration that balances heat dissipation with linearity and sound quality.

One of the defining characteristics of the Scott 399 is its fully discrete solid-state design. Unlike later amplifiers that incorporated integrated circuits, the 399 relies on individual transistors, resistors, and capacitors laid out on point-to-point or eyelet-based circuit boards. This construction method contributes to its reliability and ease of servicing—a hallmark of Scott engineering. The power supply is robust, featuring a large toroidal transformer (in later revisions) or a high-quality EI-core transformer, ensuring stable voltage delivery even under dynamic load conditions.

Technical Specifications

Power Output: 35 watts RMS per channel (8Ω, both channels driven)
Frequency Response: 10 Hz – 60 kHz (+0, -1 dB)
Total Harmonic Distortion: < 0.1% at full power
Slew Rate: ~25 V/μs (estimated based on circuit topology)
Damping Factor: > 100 (at 1 kHz)
Input Sensitivity: 1.5 V for full output
Input Impedance: 47 kΩ
Signal-to-Noise Ratio: > 90 dB (A-weighted)
Protection Circuitry: Thermal overload and DC offset detection
Dimensions: 19" (W) × 6.5" (H) × 14" (D)
Weight: Approximately 38 lbs (17.2 kg)

The amplifier features balanced (XLR) and unbalanced (RCA) inputs, a rare inclusion for consumer amplifiers of the era, suggesting that the 399 was marketed toward semi-professional and high-end audiophile markets. The front panel is minimalist, with a large central power meter (VU-style), channel indicators, and a recessed power switch. The meter serves both as a power output indicator and a diagnostic tool, helping users monitor clipping and channel balance.

Sound Characteristics

The Scott 399 is often described as having a neutral, transparent sound signature. It lacks the euphonic coloration of tube amplifiers but avoids the clinical sterility that plagued some early transistor designs. Its wide frequency response and high damping factor allow it to control speaker cones effectively, resulting in tight bass and detailed treble. The midrange is clear and articulate, making it well-suited for vocal and acoustic recordings.

Due to its low distortion and high linearity, the 399 excels at reproducing complex musical passages without congestion. It pairs particularly well with high-efficiency speakers such as the AR-3a, KLH Model Eight, or Advent Large. However, its 35-watt output may struggle with low-sensitivity or difficult impedance loads, so speaker matching is important.

Build Quality and Reliability

The Scott 399 was built to last. Its heavy steel chassis provides excellent shielding against electromagnetic interference, while the aluminum front panel and knurled control knobs convey a sense of industrial precision. Internally, components are generously sized and conservatively rated. The use of metal-film resistors, polypropylene capacitors, and high-gain output transistors reflects Scott’s commitment to long-term reliability.

Over the decades, the 399 has proven to be remarkably durable. Many units still function today with minimal servicing, though aging electrolytic capacitors and dried-up thermal paste on output transistors are common maintenance issues. Replacement parts are generally available, and the amplifier’s service manual—when obtainable—provides detailed schematics and alignment procedures.

Market Position and Legacy

In 1969, the Scott 399 retailed for approximately $450, which, adjusted for inflation, equates to over $3,500 today. This placed it in the premium segment of the market, competing with amplifiers from McIntosh, Marantz, and Fisher. While not as visually striking as some of its contemporaries, the 399 appealed to engineers, scientists, and critical listeners who valued performance over aesthetics.

Despite its high quality, the 399 never achieved the iconic status of the Scott 222 receiver or the 299 preamplifier. This may be due in part to its release during a period of rapid technological change, as well as H.H. Scott, Inc.'s gradual decline in the 1970s. The company changed ownership several times and eventually ceased production of high-end audio gear, though the brand name has been revived intermittently for consumer electronics.

Today, the Scott 399 is a sought-after collector’s item, particularly among those who appreciate understated, measurement-focused design. It is valued not only for its sound quality but also as a historical artifact of the early solid-state era. Restored units regularly appear on audiophile forums and vintage audio marketplaces, often commanding prices between $600 and $1,200 depending on condition.

Conclusion

The Scott 399 stands as a testament to the engineering rigor that defined H.H. Scott, Inc. at its peak. While overshadowed by more famous models, it delivers exceptional performance, reliability, and musicality. For the vintage audio enthusiast, the 399 offers a window into a time when high fidelity was pursued with scientific discipline and uncompromising standards. Whether used as a daily driver or preserved as a collector’s piece, the Scott 399 remains a worthy representative of American audio excellence in the late 1960s.