At the time of its release in 1980, the dbx 165 compressor limiter was conceived as the natural successor to the dbx 160, aimed at professional studios that wanted the familiar dbx sound but with a far broader and more adaptable control set. Where the dbx 160 had earned its reputation through speed, simplicity, and unmistakable character, the dbx 165 set out to refine and extend that approach, offering engineers greater authority over how compression was applied while retaining the core principles that defined dbx dynamics processing.
Design & Construction
The dbx 165 was a single channel unit, designed for mounting in a standard 19 inch rack, and could be linked to a second unit for stereo operation. It also featured the ability to separate the audio and control paths, allowing the detector circuit to be driven by an external signal. This alone marked it out as a more advanced processor than its predecessor, opening the door to creative and corrective applications that were simply not possible with the earlier design. Construction was solid and functional, with alloy front and rear panel extrusions and a clean internal layout that supported servicing and long term reliability.
Control & Operation
Control was comprehensive without being excessive. Threshold was adjustable across a wide range, compression ratio was continuously variable from 1:1 through to infinite compression, and output gain provided ample make up level. Attack and release behaviour could be set manually or switched into an automatic mode, where time constants varied dynamically in response to programme material. In practice, this made the dbx 165 far more adaptable than the dbx 160, capable of subtle dynamic shaping as well as firm control and limiting when required.
Technical Performance
Performance measurements published at the time confirmed that the dbx 165 was very much a professional tool. Frequency response was essentially flat across the audible range, with only a gentle high frequency roll off at the extreme upper end. Noise performance depended on output gain setting, as expected, but remained well within acceptable limits for studio operation. Distortion figures were low under moderate compression, with higher order harmonics increasing as compression deepened and time constants slowed, behaviour that was consistent with contemporary analogue compressor designs and rarely problematic in real world use.
Metering & Usability
Metering was another area where the dbx 165 advanced beyond the dbx 160. The front panel meter could be switched to display input level, output level, or gain reduction, providing clear visual feedback and making it easier to set and monitor compression accurately. Combined with the logical front panel layout, this made the unit straightforward to use despite its expanded feature set. Engineers at the time generally found it intuitive and predictable, qualities that mattered greatly in busy studio environments.
Market Perception & Legacy
It is striking that the dbx 165 never achieved the iconic status of the dbx 160. In today’s vintage market it is notably less sought after, often overlooked despite being the more capable and flexible processor. This is surprising given how well it performs and how effectively it builds upon the design it was intended to replace. While the dbx 160 became a benchmark for fast, characterful compression, the dbx 165 offered a more refined and versatile interpretation of that sound, suited to a wider range of sources and production styles.
Connectivity & Modifications
A defining feature of the dbx 165 at the time of its release was the use of barrier strip connections for audio inputs and outputs, a method that was popular in professional installations during the late 1970s and early 1980s. Barrier strips were favoured for their flexibility and secure wiring in fixed studio environments, but in modern contexts they are widely regarded as inconvenient and outdated. As a result, many dbx 165 units found on the second hand market today have been modified to include XLR connectors in place of the original terminals.
Unfortunately, a significant number of these conversions have been carried out poorly. Rather than precise and sympathetic modifications, many are closer to improvised hack jobs, which can compromise reliability, introduce noise, and detract from the overall quality of an otherwise well engineered compressor limiter. So shop carefully!