ADC-220 voicing

[GrandHarmonicsXII]

Hi all,

I have just recently purchased an Allen ADC-220 from a church, and should be moving it into my apartment within the next week or so. I was wondering if anyone had any information on adjusting the voicing of these instruments? It will more than likely be played exclusively through headphones.

[toodles]

Allen Organs of this era included a voicing chart that showed what voices were affected by the various voicing controls. These were BMTG: bass, treble, midrange, and gain. There should be a chart inside the back of the organ with this information. If not, Allen organ can provide a copy, I'm sure, but you might need to get it from a dealer.

[GrandHarmonicsXII]

Ok, great! Do you have any idea how many sets of controls a smaller instrument like this might have?

[toodles]

It is probably 2 sets, but at most 4 sets.

[jbird604]

Your 220 is the smallest of the MADC models, but still a nice organ in a fairly compact console. The tone generator board is identical to the board in the 420 and 520, and almost identical to the 430, 530, 221, and 222 which followed in subsequent years. You can probably find some postings on the forum that give detailed instructions for voicing these small two-channel MADC organs. The procedure is the same for all of them, as the stoplists vary by only a couple of stops.

These organs have the stops divided into two groups on the TG board, with B (bass), T (treble), M (midrange), and G (gain or volume) pots for each channel. You should find a chart in the console somewhere that will tell you which stops are in which channel. If not, you can simply turn the volume on the amp all the way down on channel 2, and make a list of the stops that still sound, which will be all the channel 1 stops. Then do the same thing by turning down amp #1 and turning up #2 to find out which stops are in that channel.

There are maybe 30 stops on the stoprail, but in fact there are only about 14 separate stops. Many stops are used in two divisions or in all three, such as the Gedeckt 8 and the Trompette 8 and so on. In reality, you only need to establish proper balance between the 8' principal (ch 2) and the octave 4 (ch 1) and then adjust the bass on ch 2 (pedal 16' stop) and the treble on ch 1 (mixture) and you'll have a pretty decent sound.

You can also read on the forum about the specific maintenance that is needed on the Allen MADC organs of that era, such as "exercising" the pots and cleaning/lubricating all the RCA plugs and jacks.

Good choice of a small organ. I had a 420 in my living room for a long time and greatly enjoyed it. I'm sure the 220 will bring you a lot of pleasure.

[GrandHarmonicsXII]

Thank you for the detailed responses! Haven't adjusted the voicing at all yet, as we just moved the organ into the apartment tonight. Might get to that this weekend.

I've found that it has a couple of issues: sticking keys on both manuals, and three severed wires in the pedal contact matrix. The first one is the one that I can't quite figure out, because I haven't figured out how to completely remove a key. Any suggestions?

Should be a useful little instrument for years to come. The practice rooms at the university I attend are becoming a bit crowded, so I started searching around and a friend of mine found a listing for this one, for a price barely more than the trailer rental to move it.

[jbird604]

Glad to hear you got a good deal. It will be nice having an organ at hand without going to the practice rooms.

You were lucky to discover the severed wires right away. I assume that fixing them will bring all the pedals to life.

Sticking keys are rare on an Allen, but Allen keyboards (except for the more recent low-end models with Fatar keyboards) have wooden keysticks similar to piano keys. Therefore they are subject to swelling from humidity, and that swelling causes the felt bushings at the front of the keys to tighten and grab the guide pins, thus making the key sluggish.

To remove a key, you remove a plastic nut under the front of the key (might have to take the wooden strip off, the one that has the pistons in it -- be cause not to stress the wires). The key will then lift up at the front -- be careful not to damage the contact leaf switch at the rear, just watch carefully what you're doing and you will be OK. The rear of the key is also held down by the tension spring underneath the key, but you might not even need to remove it all the way. Just lift up the key enough to see the red felt pieces that are glued to the insides of the slot where the front guide pin goes up into the key.

A quick way to restore smooth operation is the apply a TINY bit of pure Lanolin to the felt with a Q-tip. You don't want to get much in there just a super thin coat of it to smooth the movement of the key over the guide. Even though the trouble may have started with the swelling of the keystick, the application of Lanolin will nearly always free it up.

To get some pure Lanolin, go to a pharmacy and ask for it in a tube. Oddly enough, it is often not out on the shelves, but is kept in the racks with prescriptions, even though it's not a prescription product. It is often recommended by pediatricians as a softening cream for mothers to put on their nipples when nursing, a delicate usage, of course, but still doesn't account for why they don't just put it out on the shelves. Anyway, if you don't see it in the baby products section of the pharmacy, ask the pharmacist for a tube.

I hope that will get you up and running. After you apply the Lanolin to the felt, re-seat the key, taking care not to damage the leaf switch at the rear, getting the center balance rail slot over the center guide pin. Then gently thread the slender pin at the front back through the hole where it goes and put on the round felt punching and then the nut, tightening the nut until the key is at the same level as the keys beside it. (For black keys, use a ruler and lay across the tops to make sure you are getting the keys level with the other black keys.)

[GrandHarmonicsXII]

The Lanolin worked perfectly! I ended up having to lube 1/3 of the Swell manual, and a dozen or so keys on the Great, but they all work now. Thank you so much for the suggestion & instructions! Now I just need to go find a cheap soldering iron and I'll have the entire pedalboard working.

[jbird604]

That's great! (and swell). We once took in an Allen that had been stored in an unheated storage building for a couple of years. The wooden keysticks must have dried out and then swelled up after getting back into a more normal climate, and we had sticking keys all over the place. After the application of lanolin, it was good as new. Sold it to a church about five or six years ago, and it has continued to work beautifully.

[GrandHarmonicsXII]

Managed to get the pedalboard working & cleaned out the remnants of a mouse infestation over the last week. Couldn't be happier with it! I do have a question about the capture action though- it seems as though the church didn't order the organ with the settable combination action (only the factory preset board). Would replacing the preset board with an MADC-CP-1 board give the instrument full capture action functionality?

[jbird604]

There's a little more to it. As I recall, you don't replace the existing board, but you add a new board (MADC-CP-1) using a connector that's already there, perhaps dangling from a wire tie in the back.

Then you probably have to remove an EPROM from the CM board. There could be another step or two. It's been 20 or 30 years since I did a conversion, but the instructions are in a service manual somewhere in the shop.

I'm not sure it's worth doing, even if you can find the CP-1 board somewhere, and that's a long shot itself. Like other Allen memory boards of the era, it was built with a battery pack soldered in place, and many owners weren't aware that the batteries could leak and damage the board. So there are a great many of them out there with battery damage that probably can't be repaired. Buyer beware when you see one for sale.

Beyond that, there is the fact that even with the CP-1 board installed, you still have a "blind" combination action that is quite confusing to set (I used to get frustrated with it all the time, and I'm supposed to know exactly how to manage it). No visual indication of which stops are on with a given preset, just the LED readout in the little circle to show you that you pressed one of the pistons.

And the resources of the organ are limited, so the seven steps of the factory preset system are about as good as you're going to get when it comes to a gradual build-up. And the other seven (the "B" memory) give you seven interesting solo registrations, and you'll be hard-pressed to do much better.

I'm just saying this to play the devil's advocate. If you're determined to add the capture to it, and if you can find a working board, go for it. It was an option that some of my customers wanted back in the day, and we sold quite a few small MADC organs with capture.