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**davidecasteel** · 02-05-2014, 12:13 AM

I'm not an expert, by any means, but I think it's possible that your issues #3 and #5 may be related. A "Crescendo Pedal" is not a volume control like the "Expression Pedals" (Swell and Great Pedals). It functions by adding more and more stop combinations to increase the sound as the pedal is depressed. I think most of them have at least a dozen different levels and some have as many as 50; I believe it is also possible to alter what combinations are set up at each level in some instruments.

Regarding issue #3: If you have left the Crescendo Pedal at any position other than completely off, then there will be some stops selected and you'll hear them play. I suppose it could be possible that the Crescendo Pedal does not ever completely disengage--this would be an error, I think.

Regarding issue #5: The Crescendo Pedal is designed to engage louder and louder combinations of stops the farther it is depressed. Depending on how those combinations have been set up, the changes might seem to be abrupt (ideally not). It is also possible that some of the contacts might be dirty and the stops being engaged might not form a reasonably smooth transition as a result.

I think it is possible that the kluged speaker setup could be causing some of the other problems. I will let other, much more capable people comment on those issues (and correct any errors in my comments above).

David

**jbird604** · 02-05-2014, 07:45 AM

It's difficult to diagnose organ issues from afar, but I've been doing this for going on 40 years, so I recognize some of your problems. Your provision of so many details helps a lot.

First, the speaker issue. I suspect that only one audio channel is working. This is a two-channel organ, and most likely it has the typical MOS flute/main split of voices. (I say typical, because there were some MOS models built with a different split of voices, but we'll assume for now this one is of the typical sort.)

Channel 1 is the "Main" channel and all the diapson, string, reed, and mixture stops speak through it (except any 16' manual stops that may be present). These are of course the more "harsh" and brilliant of the voices and might sound a little rough without any flute stops mixed in. Channel 2 is the "Flute" channel and carries all the flute stops, any 16' manual stops, and ALL the PEDAL stops. So, the fact that you get none of the native pedal stops to speak might well indicate that this channel is dead. If you go back and check and discover that all the flute stops are also dead, along with the 16' reed on the swell, you can be sure that you are not hearing anything from that channel.

It could be that the wires coming out the back are not truly connected to the amps inside, or one of the speakers they have hung on it might not be both working. Or there could be a defective amplifier. There's a remote chance of a bad DAC board or even MOS board in the computer system. It's impossible to determine without opening up the console, and that is one thing I won't be able to diagnose from here.

The crescendo pedal works by simply rotating a diagonal contact bar wrapped around a wooden dowel so that it comes into contact with more and more wires (which are in parallel with the stop tabs) as it is rotated by the depressing of the crescendo shoe. It can be out of alignment, thus never shutting off fully. Or there could be something physically preventing the shoe from closing all the way. When the shoe is fully closed and there are no stops drawn, you should not hear anything when you play the keys.

There might be a TUTTI on this organ, but if it were the TUTTI stuck on, you would probably not hear anything when you add tabs to whatever registration is apparently on all the time.

There could be some stop tabs that have been damaged by someone trying to clean the switches and pressing the little thin switch blade too far, causing these stops to always be "on." Or the SBA (stopboard array), one of the computer system boards, could be defective. So, again, it may be impossible for me to tell you what is causing some stops to remain on when they should all be off. You may be able to figure it out with some careful detective work.

The card reader will fail if one critical lamp is burned out, and that is the likely cause, though there are other possibilities. The card reader system is quite simple on MOS organs and there isn't much to go wrong other than lamps and dust getting inside and clogging up the light holes over the photo-transistors. Now and then I have had to replace a card reader or the clock/logic board it connects to, but most problems are just lamps or dust. Also could be a dirty alterable selector switch, though that is unlikely if you tried it in all four positions and none of them worked.

The capture system you describe is the Sequential type. It will not "set" new combinations unless the key is in the lock and switched to the on position. Perhaps the key is not there or the lock is broken. It's remotely possible that the Set piston is not making good contact due to dirt or corrosion. If you hear the relays scanning, the action is probably OK. Several types of batteries were used over the years, but none of them are soldered on the board of the sequential system. Most likely there will be a big package containing a bunch of "D" size cells strung together to make a 27 volt battery, or else a pair of 12 volt lead acid batteries wired in series. The batteries will probably be dead, but one could disconnect them and still use the capture action. It will keep registrations in memory as long as the power cord is left plugged into the wall.

So, there COULD be almost nothing wrong with the organ. Just a bad speaker, just a piece of junk blocking the movement of the crescendo, just a missing turn-on key. Or, there could be significant problems -- a defective board or two, bad amplifier, who knows what.

If I were looking at it, I'd probably take it if it doesn't cost more than a few hundred dollars. But them I'm an experienced Allen tech and I would have it working in an hour. If you don't have a tech friend to fix it for free or very little, you will likely spend a few hundred dollars getting the various problems figured out. You will also need some "real" organ speakers, which you can often find on ebay for a couple hundred each. Or use good quality professional sound speakers that can handle the low bass of organ pedals.

It's a close call. Also depends somewhat on what you plan to do with it. These organs don't sound all that good in a home because they really need some acoustic space to sweeten the sound. For a home organ you might be better off to go with a newer Allen or else drop back to a Rodgers self-contained analog such as the Essex series. I hope this info will help you a little.

**michaelsalley** · 02-05-2014, 09:04 AM

Thank you both very much for the assistance. I learned several things.

The lock/key are present, but I was misusing them. When I read the label on the switch ("Combo Lock") I assumed that it was a safety lock that had to be "unlocked" or turned off, before I could modify things. It never occurred to me that it was the inverse of that, so I never attempted to set a memory with the key "ON".

I also never tested the organ with the crescendo pedal completely disengaged, so that could very well explain the "stuck on" stops. I've played three or four different organs but this is the first to be set up that way. I would have to practice with that for a while before I felt comfortable with it. On the surface, it seems to me that if a given registration was too soft in overall volume but pleasing in tone, the only way this Allen would let me increase the volume (unless it was entirely within the swell division with its separate pedal) is to add stops, which would by definition change the registration to a new ensemble that I might not care for as much. I'm sure it's a viable technique but it's not one I've learned; the last organ we had there was a Hammond Monarch and it used the single pedal setup.

It is a relief to hear that none of the batteries are soldered to the boards. That's one thing I do feel confident I could take care of if needed. The same is probably true of the card reader bulb.

It sounds like this thing probably could be made to operate correctly. There's always the possibility of board failure but given the mistakes I made by not knowing this design, and given the extreme likelihood of the speakers not being connected to the second channel at the moment, those would explain nearly all of my concerns.

It would be installed in a small country church with carpeted floor and drywall. The ceiling is probably 20 feet or so. Definitely not for home use, at least not at the moment. The church I grew up in has a Rodgers Essex which is wired to two speakers behind cloth covers in the front wall; I never realized that those were self-contained or could be had that way.

Thanks again to everybody who answered. At the moment, we might wait to see if the price on this one comes down any before taking a chance on it, particularly given that it would still need speakers and installation at the very least even after we owned the console. Even if we don't get this one, though, I'm very grateful for the insight about how these things work. If nothing else, I'll be better-prepared to assess the next option, whenever it presents itself.

**jbird604** · 02-05-2014, 10:03 AM

I suspect that anything about the operation that seemed peculiar to you is simply due to the audio problem and/or any misadjustment of the crescendo pedal. The crescendo and expression pedals on MOS organs work just like they do on pipe organs or almost any classical organ. The leftmost pedal is labeled "Swell" but it in fact controls the overall volume of the entire organ, swell, great, and pedal stops. So you can indeed get the tone color you desire and then vary the volume of it to suit your taste. (Unless there is also something wrong with that expression pedal!)

The crescendo pedal is normally left fully off (closed) in regular playing because you would usually want to select your stops by using the stop rail. Only when you need to quickly "crescendo" or build up a registration to full would you depress the crescendo pedal at all.

So if you go back and play it, be sure the crescendo pedal is fully closed. If it is working properly, you will get no sound at all from the keys. Then turn on stops one at a time to see which ones are dead. If my hunch is correct, you will get sound from about half the stops -- the ones playing through the working audio channel. The others will be dead, including all the pedal stops.

With stops sounding, try the expression (swell or left-hand) pedal again. It should smoothly vary the volume of whatever stops you have on. The swell pedal does not add stops or make abrupt changes to the volume.

I know a MOS organ would work in a small church, but as I said of the home install, these organs need some space to sound their best. If the church is rather dry from the carpet and pads, you might like the sound of a Rodgers analog better in there.

**michaelsalley** · 02-05-2014, 12:31 PM

Originally posted by jbird604 View Post

The leftmost pedal is labeled "Swell" but it in fact controls the overall volume of the entire organ, swell, great, and pedal stops.

What a terrible label to put on it! I read it, and assumed that it adjusted the balance of the two manuals in opposition to one another. :embarrassed:

**jbird604** · 02-05-2014, 07:51 PM

Yep, I agree. I always thought it was odd that they labeled it "swell" but it controlled the entire organ. Of course larger models will have a third pedal labeled "great/pedal" to control the volume of the lower separately from the upper.

But I think you'll find that this one works just like most any organ you've played before, even the Hammond. It's just the crescendo pedal that's throwing you off. I have worked on organs in churches where the resident organist has played an instrument for years or decades and still doesn't get the distinction between the crescendo and the swell!

Fortunately, on many organs the crescendo pedal is intentionally placed a little bit higher than the swell pedal, so you can feel with your foot that you are getting on the correct pedal. And of course the swell pedal is always located right above the E and F pedals near the center of the pedalboard, while the crescendo will be to the right of that.

**davidecasteel** · 02-05-2014, 09:11 PM

It's a historical appellation. Early organs only had one division under expression, and that was the Swell, so the pedal that controlled the shutters in that division became labeled "Swell" and the device is often simply called a "Swell Shoe". When other divisions also started being constructed with chambers and expression, the confusion began. With the advent of electronic organs in which all divisions could have expression--Katy, bar the door!

BTW, FWIW, unless special design has been included to do it, the actions of expression pedals on the sounds of pipe instruments and electronic instruments are not the same: the shutters of organ chambers do not reduce the amplitude of all frequencies equally, and this does affect the overall balance of the timbre of the division under expression; in electronic instruments the change in amplitude is the same at all frequencies (unless a "loudness" factor has been introduced into the circuitry to mimic the effect of the mechanical shutters on the sound).

David

**jbird604** · 02-06-2014, 07:32 AM

Allen expression control throughout most of their history was by a photocell (or several of them as needed for audio channels) in the expression shoe. More light from an internal lamp was admitted through a slot as the shoe was backed off. The extra light would cause the photocell to conduct more (lower its resistance), thus shunting more of the audio to ground ahead of the amplifiers, thus cutting the volume. A very elegant way to do the job, eliminating sliders or rotary pots that tend to get noisy with age. (Nowadays expression is more complicated, but the result is similar.) BTW, many other organ companies licensed this little patent from Allen, and most still use it today.

In order to make the expression work more like the shutters of the pipe organ -- which roll off the high frequencies much more rapidly than low frequencies -- every Allen expression circuit contains an "expression capacitor" -- often mounted on top of the amplifier chassis in analog and early digital organs. This capacitor is inserted between the audio line and the photocell so that the shunting effect of the photocell affects high frequencies to a much greater extent than lower frequencies.

In other words, as you close the expression on an Allen, the highs are attenuated quite rapidly but the lows diminish very slowly by comparison. The lowest frequencies, the fundamentals of the pedal stops, for example, are almost unaffected by expression, much as you would hear with a pipe organ.

Rodgers analog organs, Baldwin, etc., all used some variation on this theme to simulate the treble-rolling effect of pipe shades. However, the legendary Hammond organs notably do NOT use any such circuitry, and you will find if you close the expression pedal on the typical B-3 or other tonewheel Hammond that the audio really does go almost completely to zero, including the lowest fundamentals.

To a non-purist like me, it isn't really a big deal. I do like the fact that my Allen at church acts more like a pipe organ, and the expression pedals can be fully closed for a quiet moment in the service, producing a rich but deep tone, not a penetrating sound but still very robust in the low end. However, I've played services on a Hammond and made the adjustment easily, realizing that you cannot completely close the shoe without losing all your sound!

**michaelsalley** · 02-06-2014, 11:41 AM

I went back and tried it again this morning on my lunch hour. Much better results. We took the back cover off and I was able to locate the second channel's amp/output and connected the other speaker to it. (They had hooked two speakers to the same channel.) This did bring the pedals and flutes back to life.

Pulling the crescendo shoe all the way back to the disengaged position did correct the "voices sounding when none should" problem as well. Turning the key to the correct position "miraculously" fixed the captures as well. The swell pedal did work exactly as y'all expected.

I'm not afraid of replacing those backup batteries, and though I did not test the card reader again today (was pressed for time) it's definitely an auxiliary feature and not a primary necessity. At this point the only remaining concerns with the organ are its lack of speakers, its age (even if nothing is broken today, capacitors and circuits don't last forever), and the asking price which may be high. We'll keep monitoring the situation as we decide what we want to do.

It's definitely in better shape than I thought it was the first time. Knowing what one is doing makes a huge difference.

**jbird604** · 02-06-2014, 04:46 PM

We used to think that a 40-year-old electronic organ was toast, but I still see many MOS organs that are pushing 40 or even, now, 43 years old, and I don't see the typical age-related troubles we have come to expect in most old organs. No crumbling wires, no deteriorating plastic or rubber parts, and many of the circuit boards were coated with varnish or something when built, so they are sealed from the air and not showing their age in most cases.

Electrolytic capacitors are the components most subject to the ravages of time, and we do occasionally see them failing. We put new or refurbished amps into these organs sometimes. But we haven't seen any wholesale failure of the capacitors. I'm thinking these original MOS organs may be good for many years to come with only minimal repairs.

Keyboards and pedalboards take quite a bit of abuse, but they are easily renovated with felt parts, and the spring tension is adjustable on all keys and pedals. These organs really could last a very long time.

**michaelsalley** · 02-28-2014, 09:34 AM

Had a meeting with our pianist and a couple of Trustees this week as we keep mulling this one over. Two new questions have come up.

1. Is the 301-C tuned to A=440, or can it be adjusted to be so? It would be used in concert with our baby grand most of the time. Of course the piano will vary with temperature, humidity, and so forth, but - at least in ideal circumstances, is the organ set to 440 and can it ever "fall out" or need service to maintain? I would think that digitally generated tones would be perfect no matter what, but - measure twice, cut once.

2. I got to thinking about the two-channel audio. Realistically, I need to start shopping for speakers so that IF we pull the trigger on this, we will know our options. Our church is considered "medium" around here but would be considered small most anywhere else. Our sanctuary seats about 100-125, and the ceiling is 15-20 feet at most. I haven't measured, but I would estimate the room to be about 25-30' across and perhaps 50' from the back door to the altar. Sheetrock walls and carpeted floor. Obviously we need two speakers, minimum, or else there will be missing voices.

We don't need something that would make Stonehenge quake. The last organ was a Hammond Monarch with internal speakers, and it was plenty loud enough for all we needed it to do. We do not have cutouts in the walls for mounting speakers behind cloth grids. Anything we do will have to either be freestanding next to the console (preferred, but we don't quite know how it would sound) or wall-mounted on shelves or with whatever sort of hanger is approved for that purpose. For cost and cosmetic reasons, we'd really rather not have to hang them if we don't have to. Does Allen or someone sell a reasonably priced speaker that could stand on the floor near the console, look halfway "finished", and provide at least a small amount of protection from vacuum cleaner handles and kid fingers poking around nearby? Is there a model number I can start searching eBay and classified ads for? Before we can pull the trigger on the organ, we are going to have to figure out what we would do about speakers if we had it, and get a pretty accurate price and "installation effort" estimate on the thing. Will using 2 speakers sound halfway decent in a small room, or is four considered a bare minimum? (It apparently had four connected at its previous church; they removed it by clipping wires and leaving them hanging from the amps.) I see much discussion here of HC-12, HC-14, and HC-15 models, but those appear to be relatively un-protected and look like they were intended to be put behind screens. I see a current eBay auction for 32-a and 32-b models which look more suitable for free standing, but I know nothing about their usefulness for this application in terms of "do they have enough bass for the pedal stops to sound good".

Obviously the organist is going to get a louder ear-full if the speakers are near the console than anyone else in the room, which makes an obvious case for wall-mounting - but it would be nice to think that if we were surviving with internal speakers on the last one, there must be some acceptable compromise for this one or one like it.

Thanks again.

I realize that we're getting into a level of detail here where we would be well served by hiring a professional consultant to figure all of these things out, but - there are several problems with that. We are on a limited budget and aren't that determined/committed to move forward with an organ at all costs. This is more of an opportunistic situation than a crusade-to-find-one situation. We are a handy-enough crowd as long as we have info to work with (Which is where your help is so valuable). More to the point than anything else, we are in a rural mountain area of North Carolina and there is not even a sales dealer, much less an experienced tech who makes house calls, within 100 miles that we know of. The last guy we used to fix the Hammond "one last time" charged an arm and a leg and the machine still didn't work right when he was done. We're rather "on our own", but I'd like to think that we are capable of learning and solving this problem without a doctorate degree. Thanks again for helping to enable that.

**rohrlover** · 02-28-2014, 11:18 AM

Our sanctuary is a similar size. We have speakers mounted on the rear wall, up high on a shelf, with a couple of sub-woofers in the corners. It works very well for us. Only the people sitting at the very rear don't hear the organ all that well, since the sound is being projected above them - but that's the "price" they pay for sitting in the rear…

This allows the organist to more easily balance the organ's volume with the congregation's singing volume, also.

Our Rodgers is tuned to A440, but has pitch control +- ½ tone, so will match anything else. If I need to go more than a half tone (unlikely) I can transpose a step and tune there. I would expect the Allen could do the same.

**Admin** · 02-28-2014, 11:48 AM

The tuning is internally adjustable. You'll have to open the organ up and use a plastic alignment tool to adjust the tuning by adjusting the core of an inductor. Don't use a metal tool or force anything lest you break the ferrite core.

**jbird604** · 02-28-2014, 06:36 PM

I believe on most MOS1 organs like this, the tuning coil has a permanently-mounted stick that even has a slot in it for using a screwdriver if you need it. It is on the "clock/card-reader-logic" board which you will see when you remove the back of the organ, just to the right of the big MOS board. There may be a square metal can with the tuning control sticking out of it, or if the board is of a later design the tuning control will not be in a box, just sticking out the end of the coil.

The organ should be tuned to A440, but the control allows the tuning to be varied above and below that somewhat. Use any kind of reliable tuning meter (I use an app on my phone called Clear-Tune) and check middle C on an 8' stop. If it reads a tad low, turn the tuning control clockwise while watching the meter until it centers. If it's high, turn it the other way. (There's a chance I've got this backwards, but you'll know immediately which way to tune it.)

Your 301 will also have an analog celeste generator which must be tuned note-by-note. Once you have the digital portion of the organ tuned to A440, tune the corresponding celeste notes slightly sharp of the digital stops, and you may want to experiment to determine just how much sharpness is enough. Around 10 or 15 cents sharp at middle C is usually about right, tapering off to around 5 cents sharp in the higher octaves, but perhaps 20 cents or more in the lower octaves.

As far as speakers, the standard speakers for an organ like that would be a pair of HC-15 or possibly HC-12. Some early ones were sold with a two-box set called "32A/B" on the flute channel and a single-box called a "16-1" on the main channel. The two-part 32A/B set is extra hefty for producing the low pedal tones, but the later HC-type cabinets are certainly adequate for most situations.

You could get a pair of extra heavy-duty commercial sound speakers with 15" woofers and good-quality horn tweeters. If you get really good ones, they will have the bass response necessary for good pedal sound. Cheaper ones will wimp out on the lowest pedal notes. I really suggest getting some HC-12 or HC-15 (or HC-14) cabinets. Some of them were sold with nice furniture finishes in walnut to match the consoles, and these have good-looking grilles attached for protecting the drivers. There really isn't any magic quality to organ speakers other than they need to have flat, wide-range output, and particularly good bass output.

Wherever you put the speakers, here are some principles to think about. Consider this very seriously, because if you put them in a bad spot, the organ will not serve you well and it will be a source of frustration to the organist and the people from now on! Here are some thoughts from a guy who's been installing organs for about 40 years:

1. The organist MUST hear the organ at least as well as anyone else in the room. This is the #1 rule, and if you break it, your installation is a failure. In other words, do NOT put the speakers somewhere distant from the console or at the opposite end of the nave if it is more than perhaps 30 feet away. Make sure that the organ console is in the direct radiation field of the speakers, and not back in an alcove or under a ledge.

2. Orient the speakers so that both channels will be heard equally well in all locations (you want everyone to get a balance of both channels). If you decide to put one in each corner up front, aim them toward each other or at least very nearly at each other. Do NOT aim them straight out at the pews because people sitting near one speaker will hear nothing but flutes and pedals, and people seated near the other speaker will hear only reeds and diapasons and mixtures. Neither one will find the sound very satisfying. People will hold their ears and hate the organ.

3. The ideal height for speakers is to have the bottom of the cabinets about two feet above the heads of the standing choir members (when mounting speakers behind the choir). Even if you are mounting them somewhere else, about 10 or 15 feet off the floor is about right. It doesn't hurt to have them 20' off the floor, but put them too high and the sound may be too diffuse and foggy. The organ may sound dull and muddy as if smothered.

4. Never hang them from the ceiling or rafters because organ speakers really need the benefit of the "boundary" effect -- low frequencies are boosted dramatically when a speaker is very close to a room surface. In fact, speakers on the floor in a corner will produce the best possible bass response, but that placement is often impractical because the sound will not be well dispersed. But you will still get good bass if you place the speakers halfway up the wall as long as they are right on the wall, not out in front of the wall or some distance from any room boundary. Sometimes you can get a good effect by having the speakers down on the floor turned on their backs with the sound bouncing off the ceiling. This can give good bass response and still get the sound distributed out into the room if the ceiling is very smooth and reflective.

5. Speaking of bouncing, organ sound generally benefits from being bounced around in the room. The more reflective and lively a room is, the better the organ will sound. See if you can come up with a way to place and orient the speakers so that the sound gets bounced off the ceiling and/or walls. This can help an organ sound better in a dead room where it would ordinarily sound screechy and harsh.

6. If your first effort does not work, do it over. Don't just live with it. There is no reason why the people should be dissatisfied with the organ setup. A bad organ installation just makes people hate the organ and makes them all the more eager to throw it out and bring in a praise band.

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