Design Philosophy

The solitary goal of Dynamic Sounds Associates (DSA) is to provide the finest possible audio reproduction. To achieve this goal, we employ a “no-compromise” approach to design using best engineering principles and the finest of components. Instead of using loop feedback in our amplifiers, as with many designs, we use only inter-stage feedback to ensure that all forms of distortion are held to very low levels and to maximize the open-loop dynamic range and frequency response of our units. When frequency compensation is required, it is provided through the use of passive low-pass filter networks, with precisely controlled time constants, located between the gain stages of the amplifier chain.

This approach provides low distortion, a very high dynamic range, and eliminates transient intermodulation distortion (TIM), which is a common byproduct of configurations where the throughput gain and/or frequency compensation are controlled through the use of loop feedback. We believe that TIM is the cause of high frequency “glare,” noted in many other preamplifiers and amplifiers, regardless of application, and our designs are specifically designed to prevent TIM from occurring.

Because even the finest of coupling capacitors can cause minor—but perceptible—degradations in the reproduction of the audio signal, we avoid the use of coupling capacitors in the audio chain from input to output whenever possible. Yet, through the use of innovative designs and precisely balanced components our circuits are able to remain stable and immune to DC drift, even over years of operation.

Our designs result in audio system components with extremely wide bandwidths, and in some instances useable response to DC. Where DC response is not possible due to design constraints, the low frequency cutoff frequency is only a few Hertz; thus, permitting the maximum range of audio signals to be reproduced without frequency limits.

Our signature product, the DSA Phono ONE embodies all of these guiding principles. It uses no loop feedback, and there are no coupling capacitors in the audio chain from input to output. Precision passive low-pass filter networks between the individual balanced amplifier stages provide the RIAA frequency compensation and it offers both single ended and fully balanced outputs. In addition, the front panel provides controls for polarity inversion; including the 3.18µsec time constant in the RIAA compensation; true mono operation with the ability to perform left-right and right-left comparisons for cartridge azimuth adjustment; and, a high-pass filter for warped records.

In keeping with our dedication to designing and producing the finest possible electronic circuits, our chassis are precision machined from heavy aluminum plate using a “tongue-in-groove” design usually reserved for fine furniture. Following fabrication of the individual chassis components they are anodized for surface protection and to prevent corrosion. Lettering, or other markings, are created using laser engraving which produces a permanent marking that will never wear off or be damaged.

We invite you to view and listen to our products and let your eyes and ears determine if they do not represent the finest possible audio reproduction equipment.

Sincerely,

Douglas H. Hurlburt
Pres. Dynamic Sounds Associates, LLC.