Allen Crescendo Switch Possible?

[myorgan]

Folks,

A thought recently occurred to me. I've been at wits end with Allen's ADC crescendo pedals not having smooth action. They have fits and starts and in no way is there any smooth, usable crescendo.

However, the whisker system Allen used in the MOS series of organs was arguably much better--as well as easily customizable by bending a whisker. Those crescendo pedals had smooth action, and worked flawlessly.

How difficult would it be to switch an Allen ADC crescendo out with an Allen MOS crescendo? What's involved, and do you all think it's a viable option?

Michael

[toodles]

I think the multiplexing scheme of the ADC organs would make this pretty difficult to do--the multiplexing means that the crescendo pedal whiskers would have to contact the ground plate on the crescendo roller only when the appropriate stops were being scanned.

If it is possible (and I'm not sure that it is), it would also mean that having the crescendo engaged while setting a piston would record that stop as on for that piston. Not that anyone uses the crescendo when setting up a combination.

The one way I think it might work is if the crescendo roller wires switched on a relay--i.e., one relay for each stop--and the contacts on each relay shorted out the appropriate stop switch. It's a lot of relays and a lot of wiring.

[tucsondave]

Here's a service bulletin from Allen:

"Some Crescendo rotary switches as used on ADC and MADC models have indicated occasional noise problems.

It appears that the cause of the noise is a lubricant which the switch manufacturer uses to reduce wear. Since Crescendo pedals are not in constant use (some may never get used), wear is not a problem. In fact, our assumption is that the lubricant dries and causes the problem mainly in switches that seldom are used.

The solution is not to replace the switch. Rather, spray the switch interior with a degreasing agent such as Radio Shack #64-2322 or equivalent. This solves the problem by eliminating the lubricant.

There are two groups of four holes on one side of the switch. Spray just a light spurt into each hole and then work the switch, and then spray again. NOTE: You must place a cloth or paper towels under the switch before spraying since the residue will drip through the bottom of the switch.

CAUTION: The holes in the switch plate are smaller than the nozzle tube. Be careful not to let the spray ricochet into your eyes."

Also:
Blue Shower II (Tech Spray #1667-85)
Used for ADC organ crescendo switches and leaf type key and stop contacts.
Caution:
This cleaner will attack plastic and therefore should not be used on or near plastic key
caps and stop tabs.

td

[jbird604]

Glad you posted that, TD. I was thinking of that very thing. Crescendo pedal popping has been the bane of the ADC system for those who want to use that pedal. And it can be truly awful. Michael, I have cleaned up a lot of these pedal switches using plain old WD-40 squirted in through the holes in the side of the switch housing. I use copious amounts of WD-40 when doing this, as the old lubricant in there may have really gunked it up, and it takes a while to dissolve it and flush it out. Take seriously the advice to have a pile of paper towels (or old newspapers or something) underneath the switch as you do this. It will continue to drip out for a while after you do this, so leave the papers in place for an hour or two.

Does it completely solve the problem? Maybe not, but it does make a remarkable difference when you have a switch that is really noisy. It is actually impossible to fully smooth out the crescendo sequence, as the ADC system by its very nature introduces a little pop whenever a stop is turned on while keys are behind held down. Just hold down a chord and turn on stops, and you'll hear the pop with each stop added. So the crescendo just magnifies that pop by bringing in numerous stops in rapid fashion.

For most people in most situations, the crescendo will be perfectly OK once the switch is cleaned up per the Allen service letter above. Try it and see if you are OK with it. You will still hear the pop if you are close to the speakers, but if you are out in the audience you probably won't hear it.

[myorgan]

Dave,

Thanks for the information. I had read it before on the Forum, but was wondering if the switch from the ADC system to the MOS system would be possible or feasible. Now that I have that answer, the next pursuit is to make the ADC crescendo as quiet as possible.

It is actually impossible to fully smooth out the crescendo sequence, as the ADC system by its very nature introduces a little pop whenever a stop is turned on while keys are behind held down. Just hold down a chord and turn on stops, and you'll hear the pop with each stop added. So the crescendo just magnifies that pop by bringing in numerous stops in rapid fashion.

For most people in most situations, the crescendo will be perfectly OK once the switch is cleaned up per the Allen service letter above. Try it and see if you are OK with it. You will still hear the pop if you are close to the speakers, but if you are out in the audience you probably won't hear it.

As you know, I use my organs on stage, and rather than setting up a set of pistons, in some situations using the crescendo is a viable option--but not if it pops as it adds stops. If the ensemble or orchestra is fairly loud, I might be able to get away with a simple cleaning of the crescendo mechanism and can live with the pop as stops are added. However, if it is in a quiet section of the piece, that's not a viable option for me. It rules out using the crescendo with solo performances as well.

I know when I hold a chord and manually add stops, there is no pop. Why/how does the crescendo pedal introduce the pop when the stops do not? Is it a ground issue? I'd really like to find a way to solve this in addition to the cleaning, so I can use the crescendo pedal in performances. I have one coming up next month where the crescendo would help solve a problem, but won't know if it's possible until I hear the orchestra parts. I'll plan on not using it for now.

Michael

[jbird604]

Try the cleaning and see if that makes it usable for your upcoming performance. It can make a big difference. BTW, have someone pumping the crescendo pedal as you spray into the holes, so the liquid gets distributed over all the switch contacts in there.