Stumpff’s harps were based on the Erard Grecian design and according to James Shudi’s father John Broadwood (1732–1812) even surpassed those of Erard.
The main difference was that Erard used an external connection for the fourchettes, whereas Stumpff used an internal one, both producing essentially the same effect. Viennese piano maker Johann Baptist Streicher observed that Stumpff’s harps had a better, fuller tone than those of Erard, especially in the treble, which resulted from Stumpff’s construction of the harp soundboard with unequal thicknesses. Although Streicher may have been simply repeating Stumpff’s propaganda, his observation was similar to that of John Broadwood (1732–1812), the prominent London piano manufacturer. In 1803 Broadwood wrote to a customer who was interested in selling a piano and in buying a harp: “We will allow you 35 guineas for your Pianoforte in exchange for a new one with additional keys which we sell at 75 guineas … A Lady has a harp to sell made by Erat for which she asks 35 guineas. Erard is the most fashionable maker – but we know of no second hand instrument of his at present. Mr Stumpff, we think, makes the best Harp – his price is 75 guineas”.
This letter not only shows that a harp was as expensive as a grand pianoforte, but also provides a comparison by a contemporary author between three different harp makers working in London at that time: Erard, ‘the most fashionable maker’; Erat, a maker without any noteworthy attributes; and Stumpff, who, according to Broadwood, ‘makes the best Harp’.
The above notes taken from;
The Erard Grecian Harp in Regency England by Panagiotis Poulopoulos
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