Pinout of Allen DM-3 capture and/or Zuma MIDI boards?

[Was]

I am slowly reconfiguring a large, nonworking Allen console that I completely stripped down so that I can modify it and get it into my house. When I acquired the project last August, it had two Zuma DM MIDI Stop Controller boards installed in place of a pair of the original Allen DM-3 capture boards. The 145 drawknobs were fully working with MIDI when I received the console. Now, as I am working on refinishing and modifying the console in advance of installing a new control system, I am wondering if I can indeed simply use the Zuma boards in conjunction with the pair of Allen capture power supplies -- without the remainder of the Allen circuitry -- to get the drawknobs working with MIDI once again.

The console originally had DM-3 boards installed. The Zuma boards were installed to convert the drawknobs and, I believe, combination action to MIDI. It worked! But I intended to dismantle the majority of the console anyway and install a new control system. If I can reuse the Zuma boards, great! If not, that's okay too.

I have reviewed the entire Zuma board documentation, but I have not been able to determine much. I am hoping somebody can help me determine the pinout of the DM-3 and/or Zuma boards. The Zuma boards had connectors J80 through J83 plugged into them. As nothing is labeled, I am not sure which contacts on the Zuma boards correspond with what drawknobs, power, capture power supply terminals, etc. I would fundamentally like to sort out the drawknobs. Everything else has been sorted out through other hardware.

Where do I begin?

[samibe]

The Zuma stop controller boards work really well with the existing combination action driver and midi. The DM combination system functioned completely independent of Allen cage computer. The Zuma boards with the capture power supplies should be capable of generating midi from the stops and driving the stops with any midi signals received.

I'm not fully understanding your third paragraph. Have all of the sense and control wires (white and green wires between the stops and the DM boards) been cut? or are they still wired to the 70-pin edge connectors? Same thing with the pistons/toe stud wires?

It would be helpful if you posted some photos of the organ (especially the inside where the stop controller boards and capture power supply were located).

[Was]

The Zuma stop controller boards work really well with the existing combination action driver and midi. The DM combination system functioned completely independent of Allen cage computer. The Zuma boards with the capture power supplies should be capable of generating midi from the stops and driving the stops with any midi signals received.

I'm not fully understanding your third paragraph. Have all of the sense and control wires (white and green wires between the stops and the DM boards) been cut? or are they still wired to the 70-pin edge connectors? Same thing with the pistons/toe stud wires?

It would be helpful if you posted some photos of the organ (especially the inside where the stop controller boards and capture power supply were located).

Yes, everything has been cut because there was quite literally no way to pull everything out fully attached. I took a lot of notes beforehand, but apparently not enough. I still have everything except for perhaps a few screws or other hardware. I think I still have the terminal blocks as well, but I could be wrong. The stop jambs have almost the full length of wire still attached, ready to be attached to either new hardware or the Zuma boards again.

It would be great to be able to get the Zuma boards back up, something that was absolutely not my intention at any point prior to today. I don't mind checking things with my multimeter...I just don't want to start by doing things wrong and frying the boards.

Attached / below are two photos of the panels that contained the Zuma boards, and before that, the DM-3 boards, which I still have.

[samibe]

Do you happen to have a picture of the wires where the cuts were made?

[Was]

samibe I just grabbed the terminal blocks, which still have one to two feet in wire attached. I'm going to start trying to piece this together in a spreadsheet, I think.

[Admin]

There is no mapping of stops to pins on the Allen DM boards or the Zuma replacement as they were used in organs of various sizes and specifications. There are only input and output pins for sense and control respectively. Green wires on the even pins are control. White wires on the odd pins are sense. It therefore doesn't make any difference where the wires go provided that

• the white and green wires from the stop control go to adjacent odd and even pins on the board
• that the wires on each connector are mapped to stops in the same division, e.g. all the wires on J1 go to pedal division stops, J2 Great, etc.

[Was]

There is no mapping of stops to pins on the Allen DM boards or the Zuma replacement as they were used in organs of various sizes and specifications. There are only input and output pins for sense and control respectively. Green wires on the even pins are control. White wires on the odd pins are sense. It therefore doesn't make any difference where the wires go provided that

• the white and green wires from the stop control go to adjacent odd and even pins on the board
• that the wires on each connector are mapped to stops in the same division, e.g. all the wires on J1 go to pedal division stops, J2 Great, etc.

Is this true for J80 through J83, or just J81 through J83? I noticed J80 is a bit odd in that it has only (or at least mostly) white wires, and a lot of pins are tied to other pins. J80 also appears to go entirely to the large terminal block, which is likely for the pistons and toe studs if the labels are to be believed. I guess this makes sense since you said white wires are sense, and the pistons are just contact switches.

It is also unclear to me what pins on the Zuma board connect to N1 through N4 on the capture power supply to tell it to pulse power to a division of driver boards. N1 through N4 are labeled on the terminal block, but I am unable to trace them out successfully on the connectors that plug into the Zuma board.

As I literally had to cut everything, what would you suggest as a path forward beyond powering on a Zuma board and connecting it to MIDI? That is to say what procedures should I try with my multimeter? And to power on the Zuma board...five volts from the “+5V” terminal on the capture power supply to pin 2 on J80 and “M GND” to pin 1, correct?

With the drawknobs, am I correct in understanding, then, that the green wires / even pins on the Allen 70-pin connectors tell the transistor on the drawknob solenoid driver board which of the two coils to power (red versus blue), and the white wires / odd pins read the reed switch state / output it as MIDI messages?

I'm trying to piece this all together and understand how it works so that I can potentially put the boards back into service in a much neater console.

[samibe]

Luckily, the wiring is not very complicated. You'll need to find each pair of sense and control wires and solder them back together with the pairs of wires that are associated with the right division. You'll also need to reconnect the piston and driver wiring as well but at least they are color coordinated.

I ended up switching the wiring on some of my stops so that I could add divisional toe studs and have only the pedal stops controlled by them. I ended up making a spreadsheet to help me keep track of the wiring.

J80 is the control connector. It's what all the pistons and toe studs connect to.

[samibe]

My experience is documented here: https://organforum.com/forums/forum/...549#post530549

If having a copy of my spreadsheet would help you with figuring out how to connect it all again, I can provide a link to it.

[Admin]

Is this true for J80 through J83, or just J81 through J83? I noticed J80 is a bit odd in that it has only (or at least mostly) white wires, and a lot of pins are tied to other pins. J80 also appears to go entirely to the large terminal block, which is likely for the pistons and toe studs if the labels are to be believed. I guess this makes sense since you said white wires are sense, and the pistons are just contact switches.

.

J80 has all the connections other than those to the stop controls. That includes, power, capture supply, and piston connections.

[Was]

J80 has all the connections other than those to the stop controls. That includes, power, capture supply, and piston connections.

Just now coming back to this. Where I'm at is trying to figure out exactly what pins on J80 go to N1, N2, N3, N4, and power. Any chance you can help with this?

Can you also confirm that the Zuma boards can be used without any of the original Allen boards? See, I was trying to find what pin on J80 (I tried the other connectors too) connects to N1 through N4 on the terminal block that was mounted above, but I cannot find it. It almost looks like they go to another small board. In face, when I received the instrument, I remember one of the divisions' drawknobs not working...because a little board had fallen out during shipment. Sticking it back in fixed the problem.

Surely this isn't that complicated?

[samibe]

Wiring the boards isn't complicated. Especially with lots of photos and some documentation of how things were connected originally. Usually, when the Zuma boards are used to replace the DM capture boards only a few modifications need to be made to get it to work. It's mostly plug and play. Since you need to rewire it from the ground up, you need a more in-depth map of the connections you'll need to make. That is hard to provide through the forum. To a certain extent you're on your own. Here is a copy of the spreadsheets I made to help me keep track of the wires between the different components. (note that I called the terminal strip a "relay board".) You may end up doing a lot of tedious continuity checking to figure out which wire go where and label them so you can connect them later. I'd spend some time documenting where wires are routed to, what colors go where, and how many wires go to different areas. It may help you figure out which groups of stops/pistons/etc. are supposed to connect to which wires/plugs/terminals on the capture board/terminal block/capture power supply.

There are a few circuits involved in the wiring
- Pistons and toe studs to J80. (as well as the "Mem B" tab and other controls)
- N1-N4 from J80 to the capture power supply (CPS).
- Stop driver circuit (wires from each channel on the CPS to groups of stops)
- Sense and control circuits (white and green wires from each stop to J81-J84). Only pins 5-62 are actually used on these plugs.

Each stop has three independent circuits attached to it. One circuit goes to the multiplexer board (which you don't need). The multiplexer wires are usually colored (red, yellow, blue, and purple on my organ). The green and white (sense and control) wires go to the DM board to one of the side plugs (J81-J84). Finally, the stop driver wires run from the CPS to the stop.

The N wires control the CPS and tell it which channel to pulse (I think). You will need to make sure that you keep the divisions separate and that they end up connected to the right channel on the CPS.
On my organ, N1, N2, N3, and N4 are connected to pins 37, 39, 41, and 43 of J80, respectively.
N1, N2, N3, and N4 are supposed to drive the stops connected to J81, J82, J83, and J84, respectively.
N1, N2, N3, and N4 should also correspond to the drivers SP1, SP2, SP3 and SP4 on the CPS.
The CP channel (white wire) on the CPS is used to drive the stops that are controlled by the general pistons but not any divisional pistons. (I'm not sure how it is triggered).

Example: I have a group of stops that I want to be controlled by the same set of divisional pistons.
- I need to make sure that the divisional pistons (or toe studs) 1, 2, 3, 4, 5, and 6 are connected to pins 5, 6, 13, 14, 21, and 22 of plug J80, respectively.
- I need to make sure that the general pistons (and/or toe studs) 1, 2, 3, 4, 5, 6, 7, 8, 9, and 10 are connected to pins 29, 30, 38, 40, 42, 44, 46, 48, 50, and 52 on J80. (I'm less certain of these pins).
- I need to make sure that the sense and control wires from those stops go to the same side plug (J81 for example) and that the pair of wires from each stop go to adjacent pins (the wires from stop 1 go to pins 5 and 6, stop 2 to 7/8, etc.)
- I need to make sure a wire is connected to pin 37 on J80 and terminal N1 on the CPS.
- I need to make sure that the wire from SP1 on the CPS goes to all of the stops in the group and that a ground wire goes from all of the stops back to the CPS.

I have several question in my spreadsheets (mostly about ground wires that I'm not sure could be combined). My spreadsheet shows J80 pin 2 as the +5V power inputs and pin 1 is ground for that. There are also some ground wires on pins 45, 47, 49, and 51 that I think might correspond to the N1-N4 wires, but I'm not sure about that.

[myorgan]

EXCELLENT information, Sam! Thank you for sharing your work in detail so many can benefit from your knowledge.

Michael

[Was]

Wiring the boards isn't complicated. Especially with lots of photos and some documentation of how things were connected originally. Usually, when the Zuma boards are used to replace the DM capture boards only a few modifications need to be made to get it to work. It's mostly plug and play. Since you need to rewire it from the ground up, you need a more in-depth map of the connections you'll need to make. That is hard to provide through the forum. To a certain extent you're on your own. Here is a copy of the spreadsheets I made to help me keep track of the wires between the different components. (note that I called the terminal strip a "relay board".) You may end up doing a lot of tedious continuity checking to figure out which wire go where and label them so you can connect them later. I'd spend some time documenting where wires are routed to, what colors go where, and how many wires go to different areas. It may help you figure out which groups of stops/pistons/etc. are supposed to connect to which wires/plugs/terminals on the capture board/terminal block/capture power supply.

There are a few circuits involved in the wiring
- Pistons and toe studs to J80. (as well as the "Mem B" tab and other controls)
- N1-N4 from J80 to the capture power supply (CPS).
- Stop driver circuit (wires from each channel on the CPS to groups of stops)
- Sense and control circuits (white and green wires from each stop to J81-J84). Only pins 5-62 are actually used on these plugs.

Each stop has three independent circuits attached to it. One circuit goes to the multiplexer board (which you don't need). The multiplexer wires are usually colored (red, yellow, blue, and purple on my organ). The green and white (sense and control) wires go to the DM board to one of the side plugs (J81-J84). Finally, the stop driver wires run from the CPS to the stop.

The N wires control the CPS and tell it which channel to pulse (I think). You will need to make sure that you keep the divisions separate and that they end up connected to the right channel on the CPS.
On my organ, N1, N2, N3, and N4 are connected to pins 37, 39, 41, and 43 of J80, respectively.
N1, N2, N3, and N4 are supposed to drive the stops connected to J81, J82, J83, and J84, respectively.
N1, N2, N3, and N4 should also correspond to the drivers SP1, SP2, SP3 and SP4 on the CPS.
The CP channel (white wire) on the CPS is used to drive the stops that are controlled by the general pistons but not any divisional pistons. (I'm not sure how it is triggered).

Example: I have a group of stops that I want to be controlled by the same set of divisional pistons.
- I need to make sure that the divisional pistons (or toe studs) 1, 2, 3, 4, 5, and 6 are connected to pins 5, 6, 13, 14, 21, and 22 of plug J80, respectively.
- I need to make sure that the general pistons (and/or toe studs) 1, 2, 3, 4, 5, 6, 7, 8, 9, and 10 are connected to pins 29, 30, 38, 40, 42, 44, 46, 48, 50, and 52 on J80. (I'm less certain of these pins).
- I need to make sure that the sense and control wires from those stops go to the same side plug (J81 for example) and that the pair of wires from each stop go to adjacent pins (the wires from stop 1 go to pins 5 and 6, stop 2 to 7/8, etc.)
- I need to make sure a wire is connected to pin 37 on J80 and terminal N1 on the CPS.
- I need to make sure that the wire from SP1 on the CPS goes to all of the stops in the group and that a ground wire goes from all of the stops back to the CPS.

I have several question in my spreadsheets (mostly about ground wires that I'm not sure could be combined). My spreadsheet shows J80 pin 2 as the +5V power inputs and pin 1 is ground for that. There are also some ground wires on pins 45, 47, 49, and 51 that I think might correspond to the N1-N4 wires, but I'm not sure about that.

Oh wow, thank you so very much! This is outstanding! To answer your question, yes, below and/or attached are a few photos depicting the current state of that which I removed, intending to never use again, and intending to throw out...but did not because I was in the process of moving. Let me know if you would like to see anything else or if I should try to upload these in a higher resolution.

Also, it is my understanding that ground ground wires that went to the same ground (I believe there are two separate ones on the CPS) can be or are ultimately connected. I could be wrong, though.

I will review this more in depth and will hopefully get something connected shortly.

[Admin]

J80
pin 37 = N1
pin 39 = N2
pin 41 = N3
pin 43 = N4

[Admin]

Example: I have a group of stops that I want to be controlled by the same set of divisional pistons.
- I need to make sure that the divisional pistons (or toe studs) 1, 2, 3, 4, 5, and 6 are connected to pins 5, 6, 13, 14, 21, and 22 of plug J80, respectively.
- I need to make sure that the general pistons (and/or toe studs) 1, 2, 3, 4, 5, 6, 7, 8, 9, and 10 are connected to pins 29, 30, 38, 40, 42, 44, 46, 48, 50, and 52 on J80. (I'm less certain of these pins).
- I need to make sure that the sense and control wires from those stops go to the same side plug (J81 for example) and that the pair of wires from each stop go to adjacent pins (the wires from stop 1 go to pins 5 and 6, stop 2 to 7/8, etc.)
- I need to make sure a wire is connected to pin 37 on J80 and terminal N1 on the CPS.
- I need to make sure that the wire from SP1 on the CPS goes to all of the stops in the group and that a ground wire goes from all of the stops back to the CPS.

When using the console as a MIDI controller, it makes no difference where the piston wires go as they are virtualized by the software, i.e. any piston can be defined any function by the software. For example, although Allens of this vintage typically have 10 generals and six pistons per division, any of those pistons can function as a general, divisional, scoped, or stepper when configured by VPO software.

However, if the original capabilities of the organ are retained and it is desired to use the organ without MIDI on occassion, the correct mapping of pistons to inputs is important as the function of the piston is defined in hardware.