REDSTONE ELECTRONICS

Audio Projects

and Reference Materials


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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  and for improved sonics.

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


Speakers

CAOW1   New 9/2009

Mini-monitor, designed by Dennis Murphy, built as floorstanding version.  Uses the Hiquphon OW1 tweeter and Seas CA15RLY woofer in a vented enclosure. 
 

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 2-2014

 

 

Day-Sequerra Tuners - reference information  Updated 9-2012

 

Kenwood KT-7500

 

 

Kenwood KT-8300

 

Magnum Dynalab FT-101a

 


 Dynaco FM-3


Amplifiers, Preamps and Crossover


    Gaincard Amp with VU Meters  Webpage added 8-2015


  Tortuga LDR preamp  New 6-2015


                        in Audio Research D-150 chassis New 1-2015

  

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

 
   Levinson LNP-2 preamp  New 5/2011
 
 
New 10/2011


Reel to Reel

  Studer A80 RC - Refurb & Maintenance tips

 New 4/2015




Phono Systems



Panasonic SP-10/ SME 3009/ ADC XLM  New 5/07

 

 

    Michell GryoDec regulated Power Supply  New 1/09


Peter Daniel Phono Preamp (VSPS Variant)  New 4/09

 

 

Misc Scans of Interesting Audio Materials

New 5/2015:

New 9/2012: Amplifier Test Clinic brochures (both from mid-late 1970s):
 
 
 
 
 
 

Above: Ad for Technics RS-1506 from Audio January 1979.  Click to enlarge.

 

20000 Watt Home Hi-Fi System article from Audio magazine, April 1976.  This is also a PDF file. The cover of that magazine is shown below.

 

Cover photo (in color) from the above Audio, April 1976. 

 

Hewlett Packard 339A Distortion Analyzer review from Audio magazine, July, 1979.   PDF file.

RIMO FM Tuner Filters article by Richard Modafferi from Audio magazine, January 1979.  PDF file.

Kill FM Interference With Two Antennas article by Richard Modafferi, Audio magazine, January 1980.  PDF file.