Author: mstas

I often hear from people who have tapes they’d like to play, but aren’t sure if they can. As discussed in my post on Sticky Shed Syndrome, some tapes (many really) from the 1980s and 1990s, absorb moisture while in storage and, if not properly treated, shed oxide at a mad pace during any use. […]

Sticky Shed Syndrome (SSS) is a sad reality for high output tapes from the mid seventies through the eighties and in some cases into the nineties. This includes the following tape types: Simply put, SSS is caused by the tapes absorbing moisture and breaking down the glue that holds the magnetic material on the backing. […]

I’ve recently started working on a 3M79 24 track at Rainshadow Recording in Port Townsend, WA. It’s only been 35 years since I’ve worked on one, but it was like catching with up an old friend. Except I couldn’t remember all the details of this old friend. So I looked online to find service information. […]

I’ve searched far and wide for API 550A and 550A-1 schematics. 550A schematics are largely illegible and A-1 schematics are very hard to find. Here are links to legible versions of each as well as a schematic of the 3 transistor buffer used in the 550A: 550A Schematic 550A-1 Schematic 550A 3 transistor buffer schematic

People talk about how some equalizers are more musical than others. I recently happened upon an interesting article about API 550 equalizers that got me thinking more about that. API EQs are known for being musical, or even just a little bit magical. A little bump at just the right frequency and that’s often all […]

Overview An interesting pair of compressors passed through my shop this week.  A Fairchild 670, owned by Studio X and a buzzaudio DBC-M, owned by Resonant Studios. The Fairchild doesn’t need much introduction.  Designed in the early 1950’s and used originally for phonograph mastering and broadcasters, it is large, heavy and has a great sound.  […]

The first time someone paid me to run sound for them, I was sitting by the side of the stage twiddling the knobs of a Shure Vocal Master – or Muddle Master as my friend Steve Johnson would say! Johnny Saturn and the Electrics, a 50’s band that really just wanted someone to turn the […]

I recently had a UA 2192 come into the shop with a dead power supply. UA no longer supports the UA2192 power supply, so I dug in to repair it. Switching power supplies like the UA 2192 uses are seen by some as a black box, but in reality, they can be readily repaired so […]

After 30 years or so of wandering in the IT, Internet and software world, I’m back to where I started, working on the technology I really love; audio. Since I stepped out of the audio world in 1990, I’ve started multiple companies, had some success and learned quite a lot. Throughout it all, I’ve dabbled […]