Above is the photo of the world first commercially available class D amplifier introduced into the audio world at CES 1974 (Chicago, IL) by Spectron's president and chief designer, John Ulrick. Its power output is 250 watts per channel and it uses a switching power supply.

John Ulrick's Story

Design Team
The engineering team is headed by John Ulrick. John is supported by Jim Henderson, Ph.D., a physicist specializing in mathematical analysis and computer modeling. Their friendship and collaboration goes back to the days of Infinity. Another team member is Simon Thacher Ph.D., a retired electrical engineer with a background in digital electronics (software development) and digital signal processing. Since Simon is a former professional musician with 12 years’ formal education in classical piano, he is the engineer primarily responsible for critical listening and helping to translate the knowledge gained in his listening into engineering information. It is Simon who brings back to the entire Spectron design team everything he learns from the other members of our design team – our customers. Wayne Simoni, MSEE, is another digital processing expert, implementing his developments in digital amplification inVHDL (Very High Development Level) language. Manh Nguyen, also an electrical engineer, is responsible for all prototyping, environmental testing, manufacturing engineering and the design-for-reliability program.

Patents and Professional Audio Designs
Spectron Audio, completely involved in both audiophile and professional audio, is one of very few companies that develop their own class D proprietary modules, digital and analog. John Ulrick has been awarded 6 patents in class D amplification, including a digital input/all digital implementation. Other team members have also multiple patents, awards and more then 300 peer-review publications.

As an example, about a year ago, Spectron designs team won a contact with pro audio giant Inter-m (among others in competition were Bang & Olafson and Philips) to build a highly reliable continuous output 8000 watt power compact digital amplifier. We successfully demonstrated a prototype of the first stage of this unique amplifier at the NSCA (National Sound Contructor Association) meeting in Orlando Fl , in March of 2007. The highly innovative design includes very high level power factor corrected switching power supplies using the latest PFC conversion technology and resonant mode DC:DC converters.

Spectron has found one its major strengths to be the cross-pollenization of audiophile and professional audio designs. The design under development will, potentially,  revolutionize audiophile sound reproduction

Uniqueness of the Spectron Design
Chief Designer John Ulrick is a control systems engineer (and an amplifier is a control system). Because of this, Spectron amplifiers are designed with an emphasis on very high speed control loops. These high speed control loops result in the amplifier’s remarkable ability to reproduce detail that other amplifier’s cannot reproduce. Moreover, due to this incredible control loop speed and stability, our amplifiers can drive the most difficult speakers in the world (down to a 0.1 Ohm load!) effortlessly.

Musician III inside

Musician III is Spectron's top of the line class-D stereo amplifier. It has the sonic performance and power to satisfy everyone.


Premiere combines multi channel home theater capability with audiophile sound quality. It uses the same amplifier technology as the renowned Musician.