We can build the AVA HumDinger (DC hum blocker now). Give us a call at 651-330-9871 if you want one.
The unit has: IEC 3 conductor AC socket in and power cord, two x 3 conductor standard AC sockets out. 10 amp slow blow fuse on the incoming AC line. Size is 6" x 2.5" x 4.5" in heavy steel chassis with black powdercoat finish.
What it will do:
Block low level DC voltage sitting on your AC power line because of other devices on your line using power asymmetrically. The low level DC tends to make toroid power transformers hum, but not limited to just toroids.
The HumDinger also has a transient surge absorber on its incoming hot circuit that will somewhat reduce turn on surge currents in your equipment, prolonging power switch and electronic component life.
Plug your power amplifier into one of its AC outlets, and your preamp or a AC terminal strip for the rest of your equipment into its other AC outlet and DC related hum will be dinged.
What the HumDinger will not do:
Provide RFI or line over voltage protection. You need a dedicated suppressor for that, the simplest being an AC outlet strip designed for computer AC line protection.
Cure hum issues causes simply by a defective noisy power transformer or hum from your speakers caused by any number of grounding or system defect issues.
Note that the 10 amp slow blow fuse is provided as a very conservative first step with this product. Under normal conditions the high current, high voltage internal diode bridges won't even get warm. We can't run our system loud enough here with a Fet Valve 600R attached to heat the HumDinger up and don't blow the fuse then either. Sustained very high current demands may get the HumDinger hot. We recommend that only a single high power amplifier be connected and turned on at any given time.
The Humdinger is inexpensive, solidly made, it works, and its available now. The price for now is $140 plus $15 shipping. Again, call us at 651-330-9871 and we will build you one promptly. Standard AVA warranty and satisfaction guarantee applies.
Frank Van Alstine