In Restoration: Dynavox Rebuild
This Dynavox was originally a so-called widowmaker amplifier. We completely rebuilt it with all-new components, installed a power transformer, and revised the circuit to eliminate the obsolete widowmaker tubes. It is now a safe, functional 1.5 watt practice amplifier. It can be used alone for bedroom practice, or plugged into a second amp for interesting tube overdrive tones.
Here’s some details on how we redesigned this amp.
What is a widowmaker amplifier?
A widowmaker amplifier has no power transformer or fuse. Instead, the two-prong, non-polar power cord is wired directly to the rectifier tube. It is very unsafe, because under even minor failure conditions (such as a shorted capacitor or even - in some models - plugging the power cord in backwards), the mains voltage might end up on the guitar strings and the user will be shocked/electrocuted.
On the plus(?) side, power transformers are expensive so widowmaker amps could be manufactured and sold at a lower price. This ensured that every aspiring guitarist in America could own a low-fi death trap if that’s what they really wanted.