Quote from: David Drinkell on April 14, 2012, 09:14:31 PM
I don't agree that the design of AH's trombas was fundamentally flawed. If they were very loud indeed, they were probably intended primarily as solo stops. Everyone did this at the time - the Tromba at St. Magnus Cathedral is a Willis tuba in all but name. The 1907 Trombas at Belfast Cathedral acted as remarkably good chorus reeds to the 1975 Positive. Similarly, I wouldn't be so quick to scrap a Harmonics as people once were. They weren't/aren't nearly so anti-social as is sometimes claimed. Harry Bramma says the example at Worcester was a useful alternative to the quint mixture. I think I would prefer one to a lot of Hill tierce mixtures I have met.....
Modification/replacement sometimes works, but not always. The quint mixture which replaced the Harmonics at Leicester Cathedral worked very well, IMHO, but the similar exercise at Belfast (using some of the old pipes) most certainly didn't.
Maybe - but there is a world of difference between some Arthur Harrison Trombe and most Willis Tuba stops - even if they are by HW III, and not FHW. Whilst I realise that AH's Tromba stops were not all the same, nevertheless there are a good number still around which speak on pressures between 250mm and 300mm. King's College, Cambridge are voiced on approximately 400mm - which is just too much for G.O. reeds, to my mind - even if they are enclosed in the Solo expression box.
In any case, this is partly my point - if the G.O. reeds are too loud (or too opaque) to use as chorus stops, then they are simply too loud. On a three-clavier instrument (with or without a solo reed on the Choir or Positive), surely the most important function is as part of the full G.O. - any solo capability should be a secondary consideration.
Out of interest, were the G.O. reeds at Belfast retained exactly as before in 1975, or were they revoiced, perhaps on a lower pressure and/or with thinner tongues?
Saint Peter's, Bournemouth is a case in point. The G.O. reeds there still speak on a pressure of 250mm. Having played this organ many times (I was formerly Sub Organist for a while), I never did like them. Although they are now labelled as Posaune and Octave Posaune, they are still quite fat - and lack any attack at all, their speech being a little sluggish. I greatly prefer my 'own' reeds here - even if they do speak on a pressure of approximately 80mm - to my ears, they are infinitely more musical than those at Saint Peter's Church.
Harmonics - I am not convinced! I had understood that most piano manufacturers 'voiced' pianos so that the seventh harmonic was kept very 'quiet'. I must confess that I simply have no use for the anti-social jangle of a flat twenty-first in a compound stop. As a separate mutation, with a totally different construction and voicing, in combination with other flute ranks, it can produce some piquant effects - but even then, a stop at this pitch (or even 2 2/7ft.) has a somewhat limited appeal.