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Adding Electronics To Tracker - Pressure Switches?


Guest spottedmetal
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Guest spottedmetal

Hi!

 

Like many instruments in environments of changing temperature, my reed is always out from the flues. I've been dreaming of adding some sort of pressure sensitive switches on the soundboard clamp-on provision to wire up a rank of bells but, having had a little experience with what can be achieved with electronic extensions, am now contemplating it more seriously for an electronic reed, and some commercially available pressure sensors are now available.

 

Is it better to put opto-electronic or hall effect switches on the manuals or would pressure sensitive switches achieve better speech synchronisation?

 

In America, the attitude to electronic extensions is much more pragmatic, but I appreciate that here they are regarded as "compound organs" and to be deprecated at all costs.

 

However, the approach is interesting to me as a conservationist and heritage specialist in that such extensions can add functionality

(1) reversibly - can be taken away without affecting the orginal artifact

(2) identifiably - it is important for an object to be able to tell its story, and for additions not to be confusable with the original object

(3) whilst retaining the original artifact to retain its integrity, by reason especially of (1) and (2) without suffering significant change

(4) in extending the repertoire available to be played by a particular instrument and

(5) enable an instrument to have a new lease of life by reason of new usefulness.

 

In the posting about "What can one get for 20k" one felt that the Octopod would have benefitted from some upperwork to give it a new lease of life, and with regard to the strident strings - they were probably designed to give some feeling of brightness. The advantage of an electrical extension, most probably converted to a MIDI output, is that if not on a permanent basis, magic boxes can be plugged in at least temporarily to experiment with sounds and provide modelling for more premanent and useful solutions within the context of repertoire, placement and blend.

 

However, the facility and technique should be regarded as a tool of conservation and adaptation to modern use and requirements rather in any way providing an excuse for cheapjack shortcuts. In any event, is it better to have a pipe-organ enhanced by an element of useful electronics, or for the pipe-organ to be dumped entirely and replaced wholesale by a multi-note hifi system.

 

Sorry - my posting has gone way beyond the initial question but possibly raises a valid more general debate.

 

Best wishes

 

David P

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Hi!

 

Like many instruments in environments of changing temperature, my reed is always out from the flues. I've been dreaming of adding some sort of pressure sensitive switches on the soundboard clamp-on provision to wire up a rank of bells but, having had a little experience with what can be achieved with electronic extensions, am now contemplating it more seriously for an electronic reed, and some commercially available pressure sensors are now available.

 

Is it better to put opto-electronic or hall effect switches on the manuals or would pressure sensitive switches achieve better speech synchronisation?

 

In America, the attitude to electronic extensions is much more pragmatic, but I appreciate that here they are regarded as "compound organs" and to be deprecated at all costs.

 

However, the approach is interesting to me as a conservationist and heritage specialist in that such extensions can add functionality

(1) reversibly - can be taken away without affecting the orginal artifact

(2) identifiably - it is important for an object to be able to tell its story, and for additions not to be confusable with the original object

(3) whilst retaining the original artifact to retain its integrity, by reason especially of (1) and (2) without suffering significant change

(4) in extending the repertoire available to be played by a particular instrument and

(5) enable an instrument to have a new lease of life by reason of new usefulness.

 

In the posting about "What can one get for 20k" one felt that the Octopod would have benefitted from some upperwork to give it a new lease of life, and with regard to the strident strings - they were probably designed to give some feeling of brightness. The advantage of an electrical extension, most probably converted to a MIDI output, is that if not on a permanent basis, magic boxes can be plugged in at least temporarily to experiment with sounds and provide modelling for more premanent and useful solutions within the context of repertoire, placement and blend.

 

However, the facility and technique should be regarded as a tool of conservation and adaptation to modern use and requirements rather in any way providing an excuse for cheapjack shortcuts. In any event, is it better to have a pipe-organ enhanced by an element of useful electronics, or for the pipe-organ to be dumped entirely and replaced wholesale by a multi-note hifi system.

 

Sorry - my posting has gone way beyond the initial question but possibly raises a valid more general debate.

 

Best wishes

 

David P

 

The best electric to mechanical/pneumatic add-on system I've ever seen was cooked up by a school teacher cum amateur organ builder, the late John Norris of Newcastle-Under-Lyme. His system consisted of a magnet on the end of each pallet and a reed-switch aligned to it on each faceboard. The advantages of this system:

1. reed switches and magnets are very cheap

2. the position of either magnet or switch can be adjusted to get an earlier or later attack

3. should all of this be removed at a later date only a few little holes would be left behind

By this means and patient adjustment he got his (added) Compton 16/8/4 Trumpet rank to speak at exactly the same time as his Hill Horn which stood on a bar and slider soundboard with electropneumatic under action.

 

Having said that, I haven't been at all convinced of the effectiveness of electronic 'ranks' added to a pipe organ, with the exception of the odd 32' effect. Here the pitch divergence is likely to be very little and we are talking (in most cases) of stops which are always heard in combination with real pipes.

 

If your reed stops are always going out of tune, I think you should check

1. are they in a draught or occasional bright sunlight, or does the temperature of the whole room diverge dramatically from one day to another? Obviously if your concerts are held in a warm room, the room must be heated when the reed stop is tuned to the rest of the organ. This will make rehearsal in a cool room sound a little out of tune, but this goes for every pipe organ ever built!

2. are the critical reed stops well regulated? If a (recent) tuner has 'opened up' a decent Victorian or Edwardian stop, sometimes these ranks (which would normally be very stable) can seem much less happy. This is about the reed spring being somewhere other than where it used to sit vis a vis the curve on the tongue. I've found that once the stop is regulated to give the same tone as its voicer intended (so far as this can be guessed) a good stop stays in tune with itself pretty well. Then refer to 1. above!

 

 

If you're desperate to have further stops and the instrument isn't 'complete' in all essentials as it stands, you might consider adding a Sesquialtera or a Cornet. These will do most things a solo reed will do, but they can be relied upon to stay in tune with the fluework.

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Guest spottedmetal
The best electric to mechanical/pneumatic add-on system I've ever seen was cooked up by a school teacher cum amateur organ builder, the late John Norris of Newcastle-Under-Lyme. His system consisted of a magnet on the end of each pallet and a reed-switch aligned to it on each faceboard. The advantages of this system:

1. reed switches and magnets are very cheap

2. the position of either magnet or switch can be adjusted to get an earlier or later attack

3. should all of this be removed at a later date only a few little holes would be left behind

By this means and patient adjustment he got his (added) Compton 16/8/4 Trumpet rank to speak at exactly the same time as his Hill Horn which stood on a bar and slider soundboard with electropneumatic under action.

Wow - yes that sounds an excellent system. Thanks for sharing it with everyone!

 

Having said that, I haven't been at all convinced of the effectiveness of electronic 'ranks' added to a pipe organ, with the exception of the odd 32' effect. Here the pitch divergence is likely to be very little and we are talking (in most cases) of stops which are always heard in combination with real pipes.

 

The boxes I have been playing with have either an easy tuning facility or have a temperature compensating input . . . so one might think that they could be successful.

 

My reed is a wonderful Oboe, voiced on the verge of being a trumpet but the room is 80F in Summer and about 40F in Winter, so it really is all over the place.

 

Nevertheless

2. are the critical reed stops well regulated? If a (recent) tuner has 'opened up' a decent Victorian or Edwardian stop, sometimes these ranks (which would normally be very stable) can seem much less happy. This is about the reed spring being somewhere other than where it used to sit vis a vis the curve on the tongue. I've found that once the stop is regulated to give the same tone as its voicer intended (so far as this can be guessed) a good stop stays in tune with itself pretty well.

- such brilliant guidance - many thanks

 

If you're desperate to have further stops and the instrument isn't 'complete' in all essentials as it stands, you might consider adding a Sesquialtera or a Cornet. These will do most things a solo reed will do, but they can be relied upon to stay in tune with the fluework.

 

Good idea but uncomfortable on space available . . .

 

Does anyone have experience in putting electronic upperwork additions? This could end up a situation in reverse as the pipe organ may become playable from the two new manuals on the toaster . . . Does anyone have experience of adding solenoids in parallel to a tracker action?

 

Many thanks!

 

David P

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Does anyone have experience in putting electronic upperwork additions? This could end up a situation in reverse as the pipe organ may become playable from the two new manuals on the toaster . . . Does anyone have experience of adding solenoids in parallel to a tracker action?

Many thanks!

 

David P

 

Orange: A gentleman called Hugh Banton does this professionally. He could show you a number of organs where he has grafted electronics (in large quantities) onto existing pipe organs. I haven't heard any of them myself, no offence, but I'm not sufficiently interested. Someone proudly told me of his organ (in South Gloucestershire somewhere) how it had now doubled in size without a single extra pipe being added. I think he fondly imagined that I would be as keen as he was. He didn't get any encouragement from me at all - I still believe this procedure is the musical equivalent of putting go-faster stripes and spoilers on a vintage car!

 

Blue: This happens all the time now. Many builders here and abroad have done this - notably Nicholsons who have worked all the couplers at Southwell Minster (and elsewhere I have no doubt) by solenoids placed so that they can draw down the dedicated tracker action provided for each manual. This is nothing new - HN&B provided this sort of coupling assistance at Kidderminster Town Hall at least twenty years ago. In the case of organs with two consoles, the attached one is often tracker/mechanical throughout and the detached console uses the solenoids. If you're thinking of doing this yourself (which seems apparent) the main question would be where in the action train to add the solenoids. In a typical tracker job, there's not a lot of space below the bottom of the rollerboard (or splayed backfalls) but you could introduce something there - it would necessitate remaking the trackers/stickers. In theory you might mount a large beam of solenoids higher up but retro-fitting something like this could well upset the existing action! The solenoids you want are about 3cms wide (i.e. considerably wider than a key) so usually end up in staggered rows to keep them in line somehow. They are also pretty expensive!

 

The magnet/reed switch system could give you Midi on the pipe organ to play another electronic sound source, this would be a cheaper and less invasive way to join things up... horror of horrors!

 

[Soap and water!!]

 

What you really need is a larger pipe organ! Keep your eyes open, they are coming up for grabs all the time.

 

Off on a tangent

It is worth observing that the size of solenoid that can provide sufficient force to pull down the pallets of a ten-stop soundboard has a certain amount of inertia in it. This is potentially a much less efficient and responsive action than the traditional electropneumatic systems of old. In power consumption alone this is not a particularly good system. Interestingly, as many of us have noticed and one or two have observed here, once there are two consoles in places like Symphony Hall or The Bridgewater Hall, hardly any players seem to be interested to play on the main (mechanical) console. So much for sacred cows!!

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Off on a tangent

It is worth observing that the size of solenoid that can provide sufficient force to pull down the pallets of a ten-stop soundboard has a certain amount of inertia in it. This is potentially a much less efficient and responsive action than the traditional electropneumatic systems of old. In power consumption alone this is not a particularly good system.

 

Look closely at Lucasorg's (may I say) EXCELLENT pictures of the new organ for Worcester. You will see direct electric action intelligently applied. A small direct pallet magnet (KA) will be working in tandem with a heavy-duty pull down magnet (Heuss), opening the pallet. Theoretically, the small pallet magnet will work very quickly, relieving the pluck on the main pallet, operated by the larger pull-down magnet. Notice the shape of the pallet slot ? Narrow near the front opening, wide towards the back, where the pallet opening is less. The pull down magnets are thoughtfully mounted on something compliant, so that the frames do not resonate on the very substantial birch-ply magnet boards, and have a good working stroke of 8mm. These days, power consumption is not the thorny issue it once was. Switched Mode power supplies can deliver constant voltages and high currents effortlessly and are amazingly compact. Switching systems can drive magnets easily, without the risk of burning off key or relay contacts. I think you will find that the Heuss magnets only need about 0.5A at 12/14V.

 

I'm glad to see that Ken Tickell is prepared to stick his head above the parapet and use a much-criticised-in-theory method on a very high profile project. Perhaps some of those old theories will be blown out of the water at last ? With the design and thought that has gone into this application, I would expect to find it a reliable and robust action.

 

H

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Look closely at Lucasorg's (may I say) EXCELLENT pictures of the new organ for Worcester. You will see direct electric action intelligently applied. A small direct pallet magnet (KA) will be working in tandem with a heavy-duty pull down magnet (Heuss), opening the pallet. Theoretically, the small pallet magnet will work very quickly, relieving the pluck on the main pallet, operated by the larger pull-down magnet. Notice the shape of the pallet slot ? Narrow near the front opening, wide towards the back, where the pallet opening is less. The pull down magnets are thoughtfully mounted on something compliant, so that the frames do not resonate on the very substantial birch-ply magnet boards, and have a good working stroke of 8mm. These days, power consumption is not the thorny issue it once was. Switched Mode power supplies can deliver constant voltages and high currents effortlessly and are amazingly compact. Switching systems can drive magnets easily, without the risk of burning off key or relay contacts. I think you will find that the Heuss magnets only need about 0.5A at 12/14V.

 

I'm glad to see that Ken Tickell is prepared to stick his head above the parapet and use a much-criticised-in-theory method on a very high profile project. Perhaps some of those old theories will be blown out of the water at last ? With the design and thought that has gone into this application, I would expect to find it a reliable and robust action.

 

H

 

Hi

 

It is possible - St. Peter's Addingham - see http://npor.emma.cam.ac.uk/cgi-bin/Rsearch...ec_index=E01012 has been rebuilt with digital additions, including upperwork. The digital side is the latest incarnation of the Bradford system (the organist is Peter Comerford) - it's actually pretty good - with most stops you have to listen closely to tell what is pipe & what isn't. The biggest problem is still tuning - where do you put the temperature sensor? Incoming air, in the swell box, above unenclosed pipes? It's always a compromise. The action is electric, so the tracker question didn't arise there.

 

Special pull-down magnets are available (somewhere on this board there's a reply to my query about this from John Mander - IIRC Laukhoff supply them) - I'm considering using them on my house organ to enable a MIDI playback & a link from MIDI keyboards.

 

I would not want to do this to a truly historic organ (I did consider it for our pipe organ in church, but decided it would be too anachronistic on an 1820 chamber organ - the house organ has been "got at" so much over the years that historic restoration isn't an option). There are a number of firms offering MIDI interfaces - both from keys, and to operate pipes via solid-state relays - a web search will turn up quite a selection, mainly in the US but not entirely. The UK suppliers should also be able to help (SSL or whatever they call themselves these days among others).

 

It's certainly an interesting - if somewhat controversial - area of organ building

 

Every Blessing

 

Tony

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Look closely at Lucasorg's (may I say) EXCELLENT pictures of the new organ for Worcester. You will see direct electric action intelligently applied. A small direct pallet magnet (KA) will be working in tandem with a heavy-duty pull down magnet (Heuss), opening the pallet. Theoretically, the small pallet magnet will work very quickly, relieving the pluck on the main pallet, operated by the larger pull-down magnet. Notice the shape of the pallet slot ? Narrow near the front opening, wide towards the back, where the pallet opening is less. The pull down magnets are thoughtfully mounted on something compliant, so that the frames do not resonate on the very substantial birch-ply magnet boards, and have a good working stroke of 8mm. These days, power consumption is not the thorny issue it once was. Switched Mode power supplies can deliver constant voltages and high currents effortlessly and are amazingly compact. Switching systems can drive magnets easily, without the risk of burning off key or relay contacts. I think you will find that the Heuss magnets only need about 0.5A at 12/14V.

 

I'm glad to see that Ken Tickell is prepared to stick his head above the parapet and use a much-criticised-in-theory method on a very high profile project. Perhaps some of those old theories will be blown out of the water at last ? With the design and thought that has gone into this application, I would expect to find it a reliable and robust action.

 

H

 

I think that Grant Degens and Bradbeer used large pull down magnets on their earlier organs before their mechanical actions were fully developed but i assume they were slightly slow in acting. Gloucester cathedral action sought to overcome that with the use of multiple small lever arm magnets working directly into the bar. Whilst appreciating that Ken Tickell makes great use of many modern manufacturing techniques I wonder if the credit for this new form of electric action lies with the consultant, one John Norman?

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I think that Grant Degens and Bradbeer used large pull down magnets on their earlier organs before their mechanical actions were fully developed but i assume they were slightly slow in acting. Gloucester cathedral action sought to overcome that with the use of multiple small lever arm magnets working directly into the bar. Whilst appreciating that Ken Tickell makes great use of many modern manufacturing techniques I wonder if the credit for this new form of electric action lies with the consultant, one John Norman?

 

Yes, it's not a completely new idea (although as you mentioned Gloucester, there is no pallet in the conventional sense, only a series of pallet magnets opening into the bar) but I welcome the fact that it is being applied without any sense of covertness and where it will be evaluated very closely indeed.

 

H

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Look closely at Lucasorg's (may I say) EXCELLENT pictures of the new organ for Worcester. You will see direct electric action intelligently applied. A small direct pallet magnet (KA) will be working in tandem with a heavy-duty pull down magnet (Heuss), opening the pallet. Theoretically, the small pallet magnet will work very quickly, relieving the pluck on the main pallet, operated by the larger pull-down magnet. Notice the shape of the pallet slot ? Narrow near the front opening, wide towards the back, where the pallet opening is less. The pull down magnets are thoughtfully mounted on something compliant, so that the frames do not resonate on the very substantial birch-ply magnet boards, and have a good working stroke of 8mm. These days, power consumption is not the thorny issue it once was. Switched Mode power supplies can deliver constant voltages and high currents effortlessly and are amazingly compact. Switching systems can drive magnets easily, without the risk of burning off key or relay contacts. I think you will find that the Heuss magnets only need about 0.5A at 12/14V.

 

I'm glad to see that Ken Tickell is prepared to stick his head above the parapet and use a much-criticised-in-theory method on a very high profile project. Perhaps some of those old theories will be blown out of the water at last ? With the design and thought that has gone into this application, I would expect to find it a reliable and robust action.

 

H

 

Could any organbuilders offer an explanation as to why this method should be much criticised in theory? The only argument I can think of is the extra complexity/parts count. In the world of engineering there are many examples of the technique, for example an electrical engineering analogy;

 

Quad 909 'current dumping' audio amplifiers use a big, meaty, but relatively inaccurate amplification stages to provide the main current drive to the loudspeaker. Imperfections are then identified in this signal, and the error is cancelled out using an amplifier capable of providing a much less powerful signal, but of much greater quality. Similiar approaches are used in the amplifiers in mobile phone basestations to conserve power whilst improving the quality of the signal.

 

David.

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