Actually there’s not much of a mystery about this amplifier, besides “Why did anyone design an amplifier this ugly?” and “Why was Seth dumb enough to buy it?” (By the way, the photo above is NOT of my amp. Mine looks nowhere near that good.)
Fact is, I have a hard time passing up any piece of musical gear that is a) Cheap / Free, b) Odd or c) Broken. And this prime example of space-age musical technology was all three, in droves. In addition to really lush reverb and the famous Magnatone pitch-shifting vibrato (as opposed to “Fender-style,” which except for an early version is actually tremolo, meaning a change in volume rather than a change in pitch), this beast is literally two amps inside one. Why exactly, I’m not quite sure. The mid-60s stereo craze? When the “stereo vibrato” setting is selected, it IS a pretty impressive sound, more akin to a chorus effect than a standard vibrato (or tremolo, more likely).
I found this thing–or rather, it found me–through an informal Magnatone amp forum I subscribe to (and highly recommend). The owner lived not far away and only wanted $100 for the thing (although without the all-importand output tubes, the rare and expensive 7189A). I’d never met anyone from the forum face-to-face, but judging from the email signatures, I am guessing they are typically older blues aficionadoes. So I was surprised, not unpleasantly, to find the seller wearing an ancient Sonic Youth t-shirt, living in some sort of communal house on the Washington state peninsula.
Needless to say, the amp needed work. A LOT of work. New speakers, the output tubes plus several preamp tubes (and there are 13 tubes total in this beast!). All the electrolytic capacitors, plus quite a few coupling capacitors. Sometime in its life, someone had replaced the original power transformer with one from another Magnatone amp. Why this seemed like a good idea, I have no clue. I doubt the amp would have worked at all in this condition. This photo should give you an idea of how COMPLETELY HECTIC it is inside this amplifier.
A few months later, the amplifier was working, more or less. The aforementioned new parts, plus a few slight tweaks:
- The original speakers (1 x 8″ and 1 x 3″ tweeter per side) were changed out for new Webers, an 8″ on one side and a 12″ on the other
- Bias control was added to each side of the amp, to ensure those precious 7189A output tubes would stay happy and safe
- A variable resistor was added to the negative feedback circuit; when the amount of NFB is reduced, the amp sounds quite a bit bassier and growlier. Needless to say, many folks prefer it this way!
- “Slow” and “Fast” settings for the vibrato speed were added. Vibrato is my favorite effect, and for whatever reason I tend to slow it down on most of my amps
Out of the box, it sounded pretty great! My friend Lewi Longmire, no stranger to old and weird amps, flattered me by saying that: “For an amp with so many knobs, it sounds pretty damn good!”
However, the exterior still looked like garbage: The speaker cloth was MIA, and the Tolex so mungy as to be unusable. “No problem,” I thought. “Any dummy can recover an amplifier.” Guess who was wrong…again!
It is NOT that easy to cover a large, somewhat irregular surface with a thin, pliable covering and have it look halfway decent. After a great deal of glue, wasted Tolex and cursing, the amp looks okay. In the dark. From a distance. Not that it matters too much; the gold control plate is pretty horribly corroded, and only a few of the original knobs remain.
Almost as important as “How does it look?” is, of course, “How does it sound?” (Or do I have those two reversed?). Here are a few clips. All were recorded more or less straight to disk, through a stereo pair of Grundig GDSM dynamic mics (supposedly license-built by Sennheiser, featuring the MD409 capsule), then through modded GAP-73 pres:
Here’s the amp “plain.” Plugging into either channel gives output through both sides of the amp, though only Channel 1 gives vibrato.
Here’s vibrato added.
And finally, here’s vibrato AND reverb.
Was it worth it? Sure! Another obsolete, heavy, fragile (and let’s not forget just plain ugly) amplifier to clutter up the studio with? WHY THE HELL NOT!!! Actually, it IS a pretty fantastic-sounding amplifier. Maybe not one to lug around to every gig, but a keeper nonetheless. Just wait’ll I write about the Silvertone organ I found on the sidewalk last week!….