Meltrope soundboxes were manufactured by Amplifiers Ltd of Billet Road, Walthamstow, London E17. They sold soundboxes & accessories for gramophones. Their patented air-tight rubber compression backs were a vital component in EMG soundboxes.
- The Meltrope I, was introduced in 1927 and had a small compression fitting.
- The Meltrope II is basically the same but with a larger diameter compression fitting and an aluminium needle holder.
- The Meltrope III was a new design and one that became very successful and used on a wide range of gramophones. It can often be seen branded under different names, most commonly Decca, as it was used on their later portable models.
- The Meltrope IIIa is very rare. It came with a slotted shaft at the end of the stylus bar, into which fitted four different size chucks for different types of needles. Unfortunately the body was made from low quality "pot metal" and they are prone to expanding, seizing up the compression nut. Apparently, some also have the smaller compression fitting.