16 August 2017. Click About This Website for update list.
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site is mirrored at www.colinpykett.org.uk
over seventeen years the most stable and extensive resource on the Internet
for pipe and electronic organs
hub of this site is the Complete Articles page which gives you instant
access to many detailed articles dealing with numerous technical aspects of both
pipe and electronic organs. Use the Google search box below to quickly
identify areas of interest. While browsing, why not also listen to over 4
Ĺ hours of music
played on the three manual organ below and the Prog Organ
virtual pipe organ here?
!! NEW ARTICLE !! -
many audio channels do digital organs need?
are well known for their tendency to fatigue the ear when played loudly with many stops drawn. This commonly happens even in instruments which sound well
with quieter combinations. The phenomenon is partly due to intermodulation distortion arising mainly in the loudspeakers which causes very large numbers of spurious sum and difference tones to be added to the sound. It is quite possible for there to be hundreds of thousands of distortion products, and although each is of low
amplitude their sheer number causes an audible background of acoustic mush to arise in the radiated sound. As a result the sound loses transparency and it becomes wearisome and identifiably electronic. Pipe organs do not suffer from this defect at all.
One way to eliminate the problem is to use one or more banks of twelve independent audio channels, each handling only one note and its octaves. There is then no opportunity for intermodulation to occur. However the number of amplifiers and loudspeakers required can become excessive,
especially when several such banks are required, and this article shows how it can be reduced up to threefold using banks of no more than four channels. This simplification is possible because it is unnecessary to use separate channels for the notes comprising dissonant intervals. Their subjective coarseness in effect masks the distortion products which they generate.
This approach cannot be applied to the purer-sounding consonant intervals however, which must therefore retain separate channels for their respective notes. This is essential if all the major and minor triads are also to be radiated without intermodulation distortion, because each triad is built from consonant intervals. As triads form the foundation of all harmony, it is important to handle them properly in a low-distortion channel assignment scheme.
The article shows how to assign notes to banks of six and four audio channels to enable these principles to be applied.
Both configurations represent a considerable saving in terms of hardware and cost over that of a twelve-channel system.
The picture above is of a test rig used for experiments on pipe organ valves, such as those described in the
articles entitled Calculating Pallet
Size, Touch Relief in Mechanical Actions and
Response Speed of Electric
Actions. These can also be accessed from the Complete Articles page
where summaries are also available.
above is an experimental digital organ which simulates many different pipe
organs (Prog Organ).
the article entitled Re-creating
This electronic organ is a dual purpose instrument containing both "straight" and "theatre"
voices, designed and made by the author. It is tuned to the author's Dorset
Temperament with the addition of
some impure octaves as described in Keyboard
Temperaments with Impure Octaves. A full specification is
available for download here (PDF
file, 117 kB).
things they say:
like a town hall organ"
I didn't know better, I would say this was an Edwardian instrument with its
choir organ spoiled by turning it into a baroque-type positive forty years
later - much like many British pipe organs in other words. I love
finest electronic organ I have ever played, simply because it has a genuine
warm Romantic sound rather than spit and chiff just for the sake of
impressive - but lacking the proper starting and ending transients"
draw a stop and it sounds just like you expect it to"
nice Colin. I'm so jealous"
an engineer and I know how you do it, but not how you do it so well"
how the great diapason chorus can stand on the Claribel alone"
reeds are lovely"
you take a picture? I'm writing an article for an organ magazine and I
want to be seen at this splendid console"
recordings span some years and they were made in various rooms and auditoria. The older tracks were made using analogue
equipment and some were recorded acoustically using microphones, hence the
occasional noises due to piston thuds and page turns, etc. Other tracks
were captured electrically. All are of real players performing in real
time - no synthetic MIDI 'performances' here. I have not got round yet to
normalising the volume settings of all the tracks so they are compatible with
each other, therefore you might wish to adjust the volume between tracks
depending on which ones you select. Do not be alarmed if some tracks
appear to start with an excessive noise level - this simply means they were
recorded at a higher level than others. Just turn the volume down to suit.
In any case, it is a wise precaution to always begin playing each track at a low
level to protect your audio equipment and your ears from unexpectedly high
signal levels when the music begins. Although the instrument has 13 ranks of theatre organ voices in addition to its
'straight' sounds (see specification), copyright
considerations preclude the inclusion of much theatre-style music here. Playing time 1 hour
35 mins approx.
Canzona in D minor. BWV 588. (J S Bach)
- 5.51 MB/6m 1s
Vom Himmel kam der Engel
Schaar. BWV 607. (J S Bach) - 1.5 MB/1m
jubilo. BWV 608. (J S Bach)
- 1.2 MB/1m 19s
Minuet in D (John Stanley) - 1.70 MB/1m 51s
Choral Song (S S Wesley)
- 3.00 MB/3m 16s
Church Bells (S S Wesley) - 3.54 MB/3m 52s (also available here
played on a simulated Wurlitzer theatre organ)
Andantino in G minor (Franck)
- 5.59 MB/6m 6s (also available here played on a simulated Cavaillť-Coll
- 4.72 MB/5m 9s
Fantaisie in E flat (1st part)
(Saint-SaŽns) - 1.85 MB/2m 1s
Pastorale from Sonata no. 1 in D
minor (Guilmant) - 5.3 MB/5m 47s (borrows
the Vox Humana from the theatre organ!)
Monologue I in C
- 2.02 MB/2m 12s
III in E (Rheinberger) 3.01 MB/3m 17s
Fughetta no. 8
in A (Rheinberger) - 2.55 MB/2m 47s
Chorale Prelude on
"Eventide" (Abide with me)
C H H Parry -
3.92 MB/4m 16s
on "Abridge" (Be thou my
guardian and my guide) Thomas Adams - 2.85 MB/3m
In Tune with Heaven (Alan Gray)
- 2.75 MB/3m 0s
Chanson de Nuit
(Elgar) - 3.28 MB/3m 35s
- 3.86 MB/4m 13s
(Edward MacDowell) - 2.56 MB/2m 48s
To A Wild Rose
(Edward MacDowell) - 1.72 MB/1m 53s **
To be sung of a
summer night on the water (Delius)
- 1.98 MB/2m 10s
Andante in D (Alfred
Hollins) - 7 MB/7m 39s
- 3.69 MB/4m 2s
Berceuse (Vierne) - 3.37 MB/3m 41s
Freu' dich sehr, O meine Seele
(Karg-Elert) 1.79 MB/1m
O Gott, du frommer Gott
(Karg-Elert) - 2.19 MB/2m
Adagio in E
- 5.06 MB/5m 31s
- 2.34 MB/2m 31s
Played on the theatre organ
articles other publications
contact me about
the author about this
website Prog Organ - a VPO
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