custom audio equipment fabrication

Another Carbon Mic Power Supply

Here is a one-of-a-kind unit using a re-purposed Thordarson transformer.  IT works great, and the vintage Shurite (made in New…

11 years ago

Marantz 7 Phono Pre/ Passive Line Preamp

Above: a  Marantz 7 stereo phono stage built for stand-alone use.  See this link for an earlier build of this…

12 years ago

Vacuum-Tube Output Stage for Shure Level Loc

Many of my regular readers will be familiar with the Shure Level-Loc.  For those unfamiliar, the basics:  the Level-Loc is…

13 years ago

Audio Transformer As Signal Processor

Sometime in the past couple of years, Tape Op ran a short piece by Allen Farmelo titled "Using Transformers to…

13 years ago

Stereo Audio Power Amplifier (Home Use)

Above, a recently completed piece.  It is built on one of two identical NOS cabinets that I pulled from a…

13 years ago

Christmas 2011

Despite the hectic nature of the holiday-season, I am inevitably able to produce one piece each year as a gift…

13 years ago

The BRDCSTR

Above: The BRDCSTR, a two-stage vacuum-tube microphone preamp inspired by classic 1940s broadcast audio preamps.  Single-ended design with a 6SJ7…

13 years ago

The Old ’76

My latest microphone preamp design is completed and sounding very cool... The Old '76. The Old '76 is a novel…

13 years ago

Sound From A Glass Box

This design project began with the goal of crafting an entire amplifier that echoed the form of a vacuum tube…

13 years ago

Marantz 7 RIAA Phonograph Preamp

For my non-technical readers: a phono preamp is a device which does two basic things:  1) it equalizes the program…

13 years ago