Spectra Sonics - A Distinguished History

The history of Spectra Sonics has remained relatively removed from
public view for almost fifty years. Considered to be one of the true industry
innovators, Spectra Sonics pioneered the successful implementation
of numerous solid state audio amplifier design concepts. The legendary
Model 101 amplifier introduced in 1965, remains unchanged in design
and is manufactured with the same procedures established some forty years

Founded by William G. Dilley in 1964, Spectra Sonics rapidly became
the performance standard by which all other professional audio products
were evaluated and ultimately judged. Performance standards included
unmeasurable distortion, extremely low noise, and unparalleled dynamic
range. To this day, Spectra Sonics discrete audio amplifiers remain as
the finest performing audio devices available, irrespective of cost.

Mr. Dilley was widely known for his advanced, and innovative thinking
as well as little tolerance for band-aid approaches often taken by fellow

"Eliminate the cause, rather than minimize the effect", was a common
Dilley mandate. Design approaches of the tube era, often found their
way into solid state circuits. Impedance matching/power transfer designs
proliferated the industry resulting in mixing consoles that produced high
distortion, limited non-linear bandwidth, and inconsistent results. All Spectra
Sonics discrete audio products were designed utilizing "voltage transfer"
that employed low output impedance that resulted in linear, low distortion,
and extended audio signal bandwidth performance. This design concept
pioneered by Spectra Sonics is now accepted as an industry standard.

We are proud of the legacy held by Spectra Sonics.

We will continually update the News>> portion of this website

with further historical information, photos and links regarding all things Spectra Sonics.

Original Model 101 (Circa 1964)

Spectra Sonics Innovations:


Solid State Mic/Line Amplifiers Utilizing Voltage Transfer Design

Solid State Amplifiers Capable of 1000% Peak Overload Operating
On Audio Program Material

Compressor/Limiter Design Capable Of Independent Peak Limiting
And Compression Functions

Successful Implementation of Transformer Input/Output Isolation
In Terms Of Low Distortion And Extended Bandwidth

Introduction Of Modular Bi/Tri Amplification System Utilizing Single
Ground Plane Configuration