ALLEN ADC 2100 - Issue

[JMOrganist.MPerry]

Hello! I recently acquired a ADC 2100 and have noticed that it has divided expression, however the swell expression shoe seems to work properly, but the Great/Pedal expression shoe makes no adjustment i tone, seems like the organ seems to be programmed for the expression shoe to be bypassed and to be unexpressed. Is there a way to check or correct this problem? Also the organ says prepared for an alterable card reader system, is that a tough project to endure? Thanks again and willing to give further details if needed.

- MMP

[myorgan]

JMOrganist,

Welcome to the Forum. You can search the Forum for information on this topic. Generally, it is because the expression shoe uses a LDR (light dependent resistor) to change the gradation in sound. For each shoe, there is a light bulb with a small black dot on it. My gut tells me either your bulb is blown, or the black dot has come off the lightbulb and needs to be painted back on.

Either way, it should be a fairly simple fix for someone with limited technical skills. Let me see if I can find one of the former threads on the topic.

Michael

[myorgan]

I've looked, but for some reason cannot find results for an Allen organ. Many brands use LDRs in their expression pedals, but sometimes the function is slightly different. Until John weighs in (jbird604), or another tech, I hope this gets you on the right track.

Michael

[toodles]

The bulb in your shoe has probably burned out.

The bulb used in the expression shoe is a #57 miniature incandescent bulb with a black dot about 3/8 inch diameter painted directly atop the bulb. To access the bulb, the end panel of the swell shoe can be unscrewed, or it may be in a press-fit socket that can be pried loose. This will be the end of the expression shoe block that does not have soldered wires attached. You can readily buy a bulb without the paint, and can add the paint yourself.

Adding the alterable voices at this time is probably an impossibility, or at least an improbability. Allen no longer sells the equipment necessary to add these in the field, so you'd have to go on the used parts market, and then you can't really be sure you could find working parts.

[John Vanderlee]

Does it have a slot for a card reader?

[Admin]

A blown bulb will cause the volume to be at maximum for those voices controlled by that pedal. Some Allens(like mine) provided a tab that routes all expression through a single master expression shoe. When that tab is selected, the other shoe becomes non-functional.

Apart from the obvious question of whether your organ has such a tab, you should determine what stops, if any, are not under expression. If they are all under expression with the single shoe, suspect that a shoe has been designated as the master expression either through a tab, or custom modification.

[Larrytow]

Some Allen models came with a tab for "Great / Pedal Unenclosed". That is not the same as the "All Swells To Swell", that one might find on a theater model. Not sure about the ADC era ones though. But ya, it most likely is a burned out bulb.

[JMOrganist.MPerry]

Thank you for all your input, it turned out to be a burned out bulb, had one spare shoe around and swapped the bulbs and now the organ is functioning as it should be.