Allen 603 D audio Setup

[alakara]

Good day friends. I just got a MOS-1 Allen 603-D. Comes with a rack with 6 amplifiers. total of 14 speakers. Got a friend to help in setting it up but I doubt i already got the best from it. I need urgent help in setting it up properly

[John Vanderlee]

What is it not doing? Can you be more specific?

[alakara]

What is it not doing? Can you be more specific?

Sometimes gives some kind of static sounds from 2 of the amplifiers.

[myorgan]

Alakara,

When an organ sits for some time, sometimes oxidation will build up on parts unused. Try exercising the volume controls from the amplifiers the speakers are connected to. Just work them back and forth to help clear any oxidation that may have built up on the potentiometers inside. The volume controls are on the right-hand side of the amplifiers.

There is another possibility, but I'd rather wait until you've tried the first suggestion first. It's much more involved.

Michael

[Admin]

You need to determine whether the static is originating in the organ or the amplifiers. As suggested, exercise the pots first. If that doesn't fix the problem, swap inputs between a staticky amp and a quiet one. If the static follows, the problem is internal to the organ.

[alakara]

Thanks a lot for your comments. I will do a little more troubleshooting.

But if the static is coming from the Organ, what could be the cause, and the likely solution. I observed the static comes and goes.

Thanks

[myorgan]

Alakara,

Welcome to the Forum! I hope you continue to participate for a long time to come, and share with others what you learn here.

From the brief glance I had at your photo, it appears all the amplifiers are S-100 type amplifiers (not sure about the top-right-hand amplifier). What I'm about to describe is generic information, so hopefully, it is useful to you.

So, the sound from an MOS organ comes FROM the organ's computers, and each computer send the signal TO an amplifier. That signal can travel via RCA cable (like the ones you use on stereo equipment), or what I know as co-axial cable (perhaps Jerrold connectors?).

• INPUT-Your amplifiers all have (from RIGHT to LEFT), an amplifier pot, a co-axial connector (Jerrold?), and an RCA connector. The connectors are all inputs, depending on what your organ uses.
• OUTPUT-Further down the amplifier back (from RIGHT to LEFT), are the two spade connectors for the amplifier output, a Reset button, and the power cable.

If you wish, you can go directly FROM the outputs on the amplifier, and connect directly TO a speaker (one per amplifier).

Now, here's where John is coming from. It is helpful to know if the antiphonal relay boards on the top shelf are intended to be in the mix (probably only useful in a large house or church), or if you just plan to connect one or two speakers per amplifier (an S-100 amplifier can handle 2 speakers at once-depending on model).

Information we need to help you further:

1. What are the models of speakers you have?
2. Will you be using the antiphonal relay boards, or antiphonal channels?
3. Does your organ have any sub-woofer channels (for low bass)?
4. Are there any items BETWEEN the computer boards and amplifiers (i.e. reverb, etc.) or AFTER the amplifiers, but BEFORE the speakers?

It will also help us connect you to resources if you provide your approximate location in the world (i.e. my location is New England-if you look under my screename).

I hope that helps get you started.

Michael

[alakara]

Thanks Michael.

1) The organ came with 8 monitor II Cabinets and 2 pedal speakers (subs)
2) I will be using the antiphonal channels
3) The Organ gas subwoofers
4) No such items

Thanks

[John Vanderlee]

How does that add up to 14 speakers?

[myorgan]

Doubled speakers per channel (2x6=12), and 2 sub-woofer channels (2+12=14). I think it's called "new math.";-) That said, I've never heard of "gas sub-woofers" before. I wonder what type of speaker that is.

Michael

[beel m]

Haha myorgan. He hit g instead of h. But you knew that, didn't you?! :-)

[John Vanderlee]

I'm still trying to figure this out... I thought a 603 had 2 computers so 4 channels out? The rack has 6 amps, so would that be 4 Main and two Bass channels using a bass separator?

[beel m]

I'm trying to figure out what the sixth amp is for...
1. A computer flute/pedal
2. A computer main
3. B computer flute/pedal
4. B computer main
5. Subwoofer
6. ?????

[jbird604]

I'd suggest NOT using all the speakers that came with it, and NOT using the antiphonal relays. Why? (1) A 603 is in fact a four-channel organ, and using numerous speakers per channel tends to introduce the possibility of phase anomalies and unpleasant emphasis of certain frequency bands. The simpler a setup, the better, unless you are creating sound in a vast room seating hundreds of people. (2) The antiphonal relays are extremely prone to causing noise and distortion. They could even be the cause of your static noise. I'd take the advice offered above and simply connect one speaker directly to the output terminal of each amplifier.

Be sure to observe polarity when connecting speakers. For consistency, connect the terminal of the amp marked "Common" to the "common" terminal of its associated speaker, and connect the other amp terminal (which might be marked "4 ohms" or simply "+" or "out") to the speaker terminal with the white or red wire. Even when using only one speaker per channel, phasing is important in MOS-1 organs because the two parts of each MOS system are phase-locked, and getting the speakers out of phase will result in a puny sound quality, weak low end.

Now, as to why there are six amps on four-channel organ? Two of the amps are probably meant to drive subwoofers, so you should connect those amps directly to the two subs you got with the organ. Again, polarity is important.

A third suggestion -- for the four non-subwoofer channels, I'd suggest using speakers other than Monitor II's if you have them. Those are not Allen's best speaker cabinets, but were intended for wall-mounted applications, primarily as antiphonal speakers. They are fairly "loud" but they lack the quality driver complements of other better cabinets. If you have four type 16-1 cabinets, use those instead. Allen experts may know that the 16-1 cabinet was originally designed to be used only on the so-called "Main" channel (the one that carries diapason, strings, and reeds) but that cabinet is in fact the best open-back design that Allen ever built.

But you may not have four of those, or none of them at all, if that organ was originally shipped with, for example, HC-10 or HC-12 speakers as the primaries. If that is what you have, use four of them, as they are very good cabinets too, just slightly less efficient than the 16-1.

If you hook it up this way, you will be bypassing the relays, which can be a cause of numerous problems, and then we might have a better idea of the actual working condition of the organ.

BTW, the 603 is a nice organ. I have one in my shop right now, a slightly "customized" 603 (with one of the computer boards having a few "theater" stops that the original purchaser apparently liked better than the full set of classical stops). It's a fine organ for many purposes,

[beel m]

John, but why would you have two sub channels? The 16 and 32 stops only came out of one computer...
Still curious!

[jbird604]

Yes, the standard arrangement was to enable the lowest pedal stops only in one computer, but the capability is there for both flute channels to produce them. The one in our shop came in with the diodes all clipped off on the tone strip for the pedals in the secondary computer, and a bass channel had been added to that side. But when I used it as a rental organ for the symphony, I re-connected the pedal stops on the second computer and gave that flute channel the same audio system as the other one. Got plenty of pedal power that way!

So this MIGHT be the reason for the other amp, or it might be something else entirely. I have seen one 603 setup where one of the Main channels had a second amp feeding a speaker in an outdoor tower. It was used to play chimes (using a card of course) on the tower speaker. There are so many possible ways to "customize" a MOS organ, especially a 603 or other doubled model, no telling what the original setup was like.

With this situation, I'd like to know exactly what the "14" speakers are. If he has 8 Monitor II's, and two subs, then that only leaves four more, and they could be HC-10's, making up the original primary array. If so, I'd almost recommend connecting the four HC-10's to the four full-range outputs and dispensing altogether with the subs, and of course with the antiphonals.

[beel m]

Got it! I wish I knew, way back when, one could enable the "left" computer's pedal 16s and 32s. Thanks for the news, John. Hmm... if you do that, you should probably disable the "pedal celeste tuning" stop! (which I never understood the rationale for, except it cost nothing)

[alakara]

The pictures of the speakers are attached. So sorry I made a mistake with my initial reply to Michael. The organ came with 12 Monitor II speakers and 2 Bass (subs) speakers, Eight of the Monitor II speakers were painted white while 4 were painted brown. The bass speakers are also brown

[myorgan]

It looks like you have the 8 Monitor II speakers, and the other 2 speakers look like they have an HC-12 cabinet. Those would definitely be for the bass channel(s).

As John mentioned, it is EXTREMELY IMPORTANT you connect the speakers so there is no phase cancellation, which primarily affects bass frequencies. I use John's trick of BRIEFLY connecting a 9 volt battery (observe which side is positive and do it the same on all speakers) to the speaker connections. If the speaker goes briefly outward, make sure all the speakers do the same.

I found one of my organs for almost nothing because a member of the church involved viewed himself as a handyman, and when he replace the surrounds of the speakers, a few of them were connected with reverse polarity INSIDE the speaker. Now that it is fixed, it works great-but they did end up getting a new organ.

Michael

[alakara]

I'd suggest NOT using all the speakers that came with it, and NOT using the antiphonal relays. Why? (1) A 603 is in fact a four-channel organ, and using numerous speakers per channel tends to introduce the possibility of phase anomalies and unpleasant emphasis of certain frequency bands. The simpler a setup, the better, unless you are creating sound in a vast room seating hundreds of people. (2) The antiphonal relays are extremely prone to causing noise and distortion. They could even be the cause of your static noise. I'd take the advice offered above and simply connect one speaker directly to the output terminal of each amplifier.

Be sure to observe polarity when connecting speakers. For consistency, connect the terminal of the amp marked "Common" to the "common" terminal of its associated speaker, and connect the other amp terminal (which might be marked "4 ohms" or simply "+" or "out") to the speaker terminal with the white or red wire. Even when using only one speaker per channel, phasing is important in MOS-1 organs because the two parts of each MOS system are phase-locked, and getting the speakers out of phase will result in a puny sound quality, weak low end.

Now, as to why there are six amps on four-channel organ? Two of the amps are probably meant to drive subwoofers, so you should connect those amps directly to the two subs you got with the organ. Again, polarity is important.

A third suggestion -- for the four non-subwoofer channels, I'd suggest using speakers other than Monitor II's if you have them. Those are not Allen's best speaker cabinets, but were intended for wall-mounted applications, primarily as antiphonal speakers. They are fairly "loud" but they lack the quality driver complements of other better cabinets. If you have four type 16-1 cabinets, use those instead. Allen experts may know that the 16-1 cabinet was originally designed to be used only on the so-called "Main" channel (the one that carries diapason, strings, and reeds) but that cabinet is in fact the best open-back design that Allen ever built.

But you may not have four of those, or none of them at all, if that organ was originally shipped with, for example, HC-10 or HC-12 speakers as the primaries. If that is what you have, use four of them, as they are very good cabinets too, just slightly less efficient than the 16-1.

If you hook it up this way, you will be bypassing the relays, which can be a cause of numerous problems, and then we might have a better idea of the actual working condition of the organ.

BTW, the 603 is a nice organ. I have one in my shop right now, a slightly "customized" 603 (with one of the computer boards having a few "theater" stops that the original purchaser apparently liked better than the full set of classical stops). It's a fine organ for many purposes,

Thanks a lot for this

[jbird604]

Based on the pics, I'll guess you have 12 monitor II cabinets and 2 HC20 subs. A bit odd, but perhaps the original installers had no other options. Use 4 of the monitor cabinets on the four primary amps. Then use the two subs on the other 2. I'm assuming the other two are in fact bass channels, but they may not be, as discussed above. But you can probably figure out what stops are coming from that amp.