Magnasync Tube Mic Preamp

THE RESTORATION

An unusual posting on Facebook Marketplace caught my eye: a retired film professor selling an assortment of vintage film cutting/editing equipment. One device caught my eye--a small box with an oversized VU meter and chunky knobs & switches. I had no idea what it was, but it looked intriguing. According to the web, Magnasync, its manufacturer, made the Moviola, a popular editing machine for editing 35mm film. There was little to no information about this amp that I had, but its original Cannon XLR connectors implied it had something to do with microphones. The internal components were extremely high quality, with Triad transformers and two modular preamp cards, one of which was designated for microphones. My heart sank when I noticed some ominous black goo spilling from the leads from the massive power transformer. This is typically a sign of some catastrophic failure, potentially the transformer itself. I brought the amp up gradually to 120VAC wall voltage using a variable transformer and it seemed to power on well with no smoke or blown fuses. After some additional sleuthing, I was able to determine that a previous attempt to add a grounded power cable had likely caused a momentary short and stressed (but not killed) the PT.

THOUGHTS & IMPRESSIONS

After a full electolytic recap, the preamp performed very well on a variety of microphones, including ribbon mics. (Some of the mics tested included: Shure SM7B, Shure SM57, Warm Audio WA-47, Beyerdynamic M160) The Magnasync has an impressive 72dB of gain and yields a very lush & beefy sonic character. Its "Dialogue Equal" switch on the back panel enables a nice presence boost for vocals or guitar. Speaking of guitar, the 1/4" "Bridging Input" jack is a perfect D/I input that sounds terrific for both guitar and bass. The Magnasync Recording Amplifier is truly a hidden gem that holds its own against more noteworthy tube preamps and its portability can be very handy for use as a D/I. If an Ampex 351, RCA OP-6, or Telefunken/TAB V72 is out of your price range, look for one of these preamps. I absolutely love it and I'm confident you will too. Check out some of the photos.