Mackie PSU
Posted: Sat May 21, 2011 12:18 amMackie Designs SR series and 1604 and below mixers amongst others have power supplies with finite lifespans.
Symptoms are not limited to but can include decreased headroom, increased noise, hum, ghosty LED's, and logic faults.
Expect troubles as early as as 5 years of service. Below is a picture that should demonstrate a facet of this.
As a rule when rebuilding linear PSU's I replace at a minimum all electrolytic capacitors, voltage regulators, diodes and bridge rectifiers. It should also be stated that Aluminium Electrolytic capacitors themselves have both a shelf life and a service life, most capacitors beyond ten years old could benefit from replacement. Rebuilding power supplies is the most common service I perform here at the shop second only to guitar amp re-tubing and biasing.
Symptoms are not limited to but can include decreased headroom, increased noise, hum, ghosty LED's, and logic faults.
Expect troubles as early as as 5 years of service. Below is a picture that should demonstrate a facet of this.
As a rule when rebuilding linear PSU's I replace at a minimum all electrolytic capacitors, voltage regulators, diodes and bridge rectifiers. It should also be stated that Aluminium Electrolytic capacitors themselves have both a shelf life and a service life, most capacitors beyond ten years old could benefit from replacement. Rebuilding power supplies is the most common service I perform here at the shop second only to guitar amp re-tubing and biasing.