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Solid State Sytem Misbehaving?


Guest Cynic
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Now I'm pretty ignorant where solid state is concerned. I have in my care an instrument with such a system dating back to the mid 1970s, the job consists of three ranks + repeating mixture - a later example of the standard Walker Positif models. Generally it's been fine, all faults on re-installation have been tracked down, except....

 

according to an intelligent priest who understands about music, there were weird unexpected notes coming out of it a few days ago. They were described to me as 'like stars' just coming out 'any old how' without much suggestion that the player could be at fault. Needless to say, I turned up early yesterday to check it over before the morning Mass. Worst scenario, if what was actually happening were damaged contacts touching or dirt in a few pallets I would just have removed a few pipes to get them through the service. What did I find? The organ appeared in perfect playing order, nothing apparently wrong at all.

 

I don't think he dreamed it, and in this particular case we have a Catholic Priest with all his marbles and without a drink problem.

So..has anyone out there in Mander Forum Land come across an organ behaving like this and could it be the solid state?

 

All comments gratefully received.

[Apart from those who suggest that the church should have bought a tracker organ, please.]

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ALERT Totally useless response following.

 

They were described to me as 'like stars' just coming out 'any old how'

 

My wife always describes the sounds mutation stops make as "twinkly"... :blink: Maybe the priest had never previously heard the mixture used?

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Guest Patrick Coleman
ALERT Totally useless response following.

 

 

 

My wife always describes the sounds mutation stops make as "twinkly"... :blink: Maybe the priest had never previously heard the mixture used?

 

This is actually not totally useless. When I am migrainy (if that's how you spell it) I can hear harmonics that otherwise pass me by. Mixtures and single mutations can sound almost painful when I'm like this. So maybe that's the answer...

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That certainly strikes a chord with me as, and without being flippant about migraines, on occasions in my younger years the use of mutations at an all too early Sunday morning service exacerbated the after-effects of an all too late Saturday night and actually hurt, making the headache worse.

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So..has anyone out there in Mander Forum Land come across an organ behaving like this and could it be the solid state?

 

All comments gratefully received.

[Apart from those who suggest that the church should have bought a tracker organ, please.]

 

Yes indeed, our previous organ showed exactly the same symptoms. It had a digital transmission between organ and console, and in its latter years (after it was around 15 years old) developed a tendency to sound notes at random - often high-pitched pipes with short duration bursts of sound. Completely beyond the control of the organist, whose only recourse was to turn it off completely, or to remove/silence the most commonly affected pipes.....

 

These digital systems use a multiplex to transmit console data to the sliders and pallet magnets. Random errors in the bits transmitted can cause anything to happen, often momentarily and not repeatable. What I am not sure about is why these circuits seem to show such faults on ageing, and why there is not sufficient error-correction built in to counter it. It doesn't happen on aeroplanes...I hope.

 

Said organ has now been removed, to be replaced with a completely mechanical instrument (apart from the blower, that is).

 

JJK

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If the circuitry is not well screened, and thus susceptible to RF interference, the problem might be not so much ageing as the recent introduction of many RF sources into the church - mobile phones! (More so if the church is playing host to a phone mast.)

 

Paul

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If the circuitry is not well screened, and thus susceptible to RF interference, the problem might be not so much ageing as the recent introduction of many RF sources into the church - mobile phones! (More so if the church is playing host to a phone mast.)

 

Paul

That's an interesting idea! There is no nearby mast, but I had noticed that the problem always seemed at its worst during weddings - when I suspect there is generally a higher concentration than usual of switched-on mobiles....

JJK

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Many years ago, the organ in Queenswood School Chapel in Hertfordshire suffered terrible problems because of its proximity to Brookmans Park transmitting station. Ciphers would suddenly occur, and the stop and piston actions seemed jinxed. My scheduled organ recital there was cancelled because of the organ's sheer unpredictability.

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It's hard to answer this one without knowing the relationship between the note played and the extraneous notes sounded. The suggestion of the oft unused Mixture is very plausible to me. Is the Mixture a mixture 3 ranks 1-61, or a repeater, or taken from a selection of other ranks a la Compton. I'd expect it, on your description to be a 3 rank repeater. If so, I would start my checks with a multi meter following the voltage path looking possibly for something like a failed diode allowing the current to return along a path it should not. Impossible to know really until you catch it in the act. Suggest you check for spider's webs as these are quite conductive on solid state.

 

AJS

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The Cathedral organ on which I was organist was solid state with a moveable console. It regularly used to act up playing wrong notes and it would select wrong stops also. Pulling the Swell 15th would regularly give the pedal trombone - but playable on the great! The organ has since been completely replaced.

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Well, it depends on the action system.... but on a slider soundboard instrument one reason for hearing those errors only with mixtures or high pitches might be that the time the wrong notes occur is so short that only the smallest pipes are able to respond.

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If the organ has an inbuilt MIDI interface, perhaps making a MIDI recording when the priest believes wrong notes to be being played might help?

 

On the other hand, if I had an instrument with such an action and wanted to motivate people to replace it... ! :lol:

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If the organ has an inbuilt MIDI interface, perhaps making a MIDI recording when the priest believes wrong notes to be being played might help?

 

On the other hand, if I had an instrument with such an action and wanted to motivate people to replace it... ! :(

 

If there is a problem with the control system then recording from the MIDI interface may not record the symptom. This is because the problem could be occuring somewhere after the MIDI interface point in the chain of equipment. For example most MIDI interfacing takes place where the key and stop data are still separate, but the problem could be in or after the coupling processing.

 

John R

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  • 2 weeks later...
If there is a problem with the control system then recording from the MIDI interface may not record the symptom. This is because the problem could be occuring somewhere after the MIDI interface point in the chain of equipment. For example most MIDI interfacing takes place where the key and stop data are still separate, but the problem could be in or after the coupling processing.

 

John R

True, however there is still much that could be addressed with this approach. It would allow Cynic to sit in the nave with the priest and listen to what is happening if the priest hears the problem again. Then, the possibility of Mixture with migraine, notes played too short to sound properly, and the result of leaving a mobile phone near the system could all be checked and possibly eliminated.

 

Having taken a side step in life for a while and worked as an Electronic Engineer in a research institution then in a spin off company that produced both PC software and embedded software, and having been the person who was the engineer turned to when others had failed to locate problems, I can vouch for the methodical approach, looking at one subset of possibilities, and indeed one possibility at a time.

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