R7 Construction
10/4/09
concept: 
reality...... partway 
Not all the pieces are attached but the shape is seen.
Proposed finish: high gloss lacquer black
build-up: stacked layer baltic birch using 1/2 inch layers
Roughed in and checking the fits
Back view. Noting the location of the KAB PC-1200 connector plate which holds the RCA output jacks and ground stud. An IEC input socket will accept a PC style power cord.
(hint: click on thumbnail to view full sized image)
close-up of the KAB PC-1200 RCA bracket.
From above. Evaluating the stock finish on the motor plate. Imagining how it
will contrast with the multi-coat gloss black lacquer finish that is to be
applied to the plinth.
The Cherry armboard has yet to be cut. For now the stock Thorens board has been drilled to fit the Jelco SA-370H tonearm. This setup will be used for initial / preliminary evaluation. Then the Cherry board will be prepared and fitted as the final bit of construction.
Paints have been purchased for the wood plinth. A lacquer sanding sealer from Minwax will be used initially to seal up the porosity within the wood. Then Ditzler D73Q (Kondar) primer surfacer will be applied/sanded/applied multiple times as a preparation for the top coats which will be Ditzler DDL9300Q (lacquer black). The sealer applications will begin tomorrow.
Black Lacquer
12/6/09
The plinth is not entirely from a Baltic Birch build-up. There are three
motor plate supports from Gabon Ebony. The shims seen in the photos are LE
Phenolic and Delrin.
Reassembly
12/13/09
Beneath the motor plate. A very simple assembly.
A close-up detail of the "suspension" unit. This rubber assembly
replaces the original conical coil spring for a much firmer, less bouncy
isolation medium. When the building structures we live in are designed to
be flexible, and with springy floors, this is one practical solution to the
footfall issue. In practice, these spring substitutes make no sonic
sacrifices in comparison to the spring suspension. To my ear, an
improvement is heard in pace, timing and rhythm.
Delrin shims are used between the armboard and subchassis. The Delrin pad maintains a rigid mechanical connection while providing a resonant filter to assist in reducing the amount of resonant transfer between armboard and subchassis. In this build-up, the Cherry armboard is meant to be the sole structure that absorbs any resonance traveling off the tonearm.
Showing the AC hook-up just before mounting the 'iec' socket. To
disassemble the turntable assembly from the plinth, this will be one of the
first items to "un-hook" before being able to lift the top motor plate
up and out of the plinth.
Adjusting motor azimuth for best belt tracking/speed shifting.
First a session with the hfnrr test record, then....some early listening.
