Since my last post about the 1401, minor alterations were made to the layout to lower the noise floor and raise the output level capability. It is now complete and available for purchase here on the site. Details about the 1401 Stereo Microphone Amp can be found here.
The Ghost Box (pictured above the 1401 Preamp) was built as an add-on to give the 1401 all the typical features commonly associated with mic preamps. Its main feature is phantom power, but it also provides switches for phase invert and low cut. The Ghost Box is stereo to compliment the 1401 Preamp, but it can be used with any mic preamp as a sonic alternative to on-board phantom power.
There's a few interesting things to note about the Ghost Box. First off, its 100% valve state (like everything made by Lightning Boy Audio). That might not sound too strange unless you're familiar with phantom power enough to know devices that deliver phantom power are traditionally powered by solid state power supplies. Usually with phantom power, it needs to be well regulated so that the microphones being powered by it can operate with low noise. The use of solid state voltage regulators is common in the industry. Furthermore, phantom power was first introduced when solid state condenser mics came about. I doubt anyone considered building a tube based phantom power supply because few people are as crazy as I am and its considerably more expensive to do... not to mention the design challenges involved.
The Ghost Box departs from traditional phantom power by deriving its 48vDC from a vacuum tube rectifier and a neon voltage regulator tube.
What's so special about that you might ask? Well aside from it being a new concept, there is an obvious sonic difference between using a solid state phantom power supply and the all-tube Ghost Box. Check out this demo video with some decent speakers or headphones to hear the difference yourself!
About the Author
Mike Congilosi II, Inventor/Engineer