Redstone Electronics is a custom electronics design, construction and modification service focused on high end audio.  We design & build new equipment and modify older high end equipment for both reliability reasons (electrolytic caps, for example, typically last 20-30 years before failing) and for improved sonics (replacing older parts with higher performing, closer tolerance new parts).

This webpage documents some of my work and contains reference materials for those technically inclined.

Speakers

CAOW1   New 9/2009

Fried Model H

This landmark 3 way speaker system designed by Irving Fried in 1978 consists of two small satellites plus a large common dual channel transmission line subwoofer, using classic KEF drivers.  

Fried Model B/2  New 6/07

This mini-monitor speaker was an evolution of the satellite of the Model H, and competed with the Rogers LS3/5a and JR 149 among others.  With the Model T subwoofer (below), it formed the Model H/2 system.   Lots of reference material here.

Fried Model T subwoofer  New 3/09

Reference materials, including plans and crossover schematic, on this dual transmission line woofer.                 

   Satterberg woofers  New 5/08

 

Digital Audio (USB DACs)

    Scott Nixon USB DAC  NEW 3/08

 

Peter Daniel USB DAC  New 3/08

      Power Supply for Wavelength Brick USB DAC  New 2/09

 

Tuners

Sequerra Model 1 FM Tuner  Updated 4-09

 

 

Day-Sequerra Tuners - reference information  Updated 4-09

 

Kenwood KT-7500

 

 

Kenwood KT-8300

 

Magnum Dynalab FT-101a

 

 Dynaco FM-3

 

 

 

Amplifiers, Preamps and Electronic

Crossovers

 

Audio Research SP-3 preamp  Updated 10/07

 

Audio Research ST-70-C3 amplifier  

Updated 10/08 with Bill Johnson mod suggestions

 

 

 MPB's Electronic Crossover  New 9/07

 

 

  Audio Research VT-100: Adding a tube timer 

  New 5/07

  Gainclone Integrated Amp with USB DAC  New 10/08

Dahlquist DQ-LP1 Crossover

New 10/2011