To hear a similar 4 spring soundbox in action, please go to youtube & type into the search=
Hand-made Gramophone soundbox based on the E.M.G 2 spring type . All Brass construction.
A fine, open sounding soundbox that has been built to the specification of those made in the 1930's by E.M.G of Grape Street London & which used the fine quality, English made, H.M.V Exhibition soundbox as the basis for their own designs with a small diaphragm measuring 42 mm Diameter,
The excellent Gramophone museum website lists the original EMG 2 spring soundboxes on their EMG archive pages which has been used to make a faithful reproduction, inside & out !. the needle port is the hole-through type machined for Fibre, Triangular needles to preserve a cherished record collection.
.The entire front form has been hand machined from good quality Brass stock & the fixings have been tapped to the correct B.A threads used bt the E.M.G company in the 1930's. The soundbox back plate has been built with a useful "Wright Back " Tone arm fixing, used by EXPERT, EMG & the Meltrope Company. The needle bar springs are a set of 4 newly made "CLAW" springs, that the EMG company was famous for & in the correct gauge spring steel, To allow for precise pressure adjustment to finely adjust the needle bar to find that all important "Sweet spot" for various music genres. A newly pressed Aluminium Diaphragm of the correct gauge & that follows the design of the types used by EXPERT & E.M.G has been used & the tone is really nice ! . The B.A rear fixing bolts are slightly over length allowing rubber packing to adjust the diaphragm pressure that was a common fine tuning method during this Era on soundboxes from Expert & E.M.G ( see Percy Wilson's & G.W. Webb's book "Modern gramophones & Electrical Reproducers -1929") Chapters 3 & 4 .
I have set this up as best as I can but the soundbox would benefit from being set-up by somebody with more experience.
New rubber diaphragm isolators have been fitted as well as a new tone arm fixing rubber sleeve that allows fixing to DECCA at 18mm Diameter & HMV at 19mm Diameter.
A good chance to experience the Tone of an Ultra high end 1930's soundbox Nearly identical to the E.M.G originals, but without the 4 figure price tag.
Quite a heavy soundbox weighing around 200 Grammes & as the upper section of the needle bar diaphragm connection has been case-hardened & Tempered, This sound-box is most suitable to use with either Triangular Bamboo needles or Burmese Colour Needles to preserve a cherished record collection.
Will be packed very securely with the carton pictured.
Thanks for looking.