Allen MIDI Installation Issues (OEM Card)

[myorgan]

Hello,

I added Allen’s OEM MIDI card and installed it per the instructions I had, and it’s not working properly. Could y’all please listen to the attached recording and tell me what you think it may be (repeated, weak notes). Please forgive the buzzing sound, but it was due to using my Macintosh laptop’s internal microphone.

To connect the different manual divisions, I connected the Swell and Pedal to two separate blank drawknobs on the respective jumper strip pin (per the chart I had). They were supposed to be intended for the Brass Choir and Vibrato. I connected the Great MIDI to a blank drawknob on the Great (intended for vibrato).

Preparation Procedures

• I disconnected the Bass Coupler (not working well anyway), so that card is out of the mix.
• I put computer audio through the amplifiers using a Y-splitter and the sound worked great.
• I checked my MIDI Ensemble II with good MIDI cords on piano, and outputs worked great through piano.
• I checked all organ sounds, and they all work well with & without the card connected.

Recording
I recorded tonight using my MIDI Ensemble II.

• 0:00—Checked stops beginning with Great, Swell, then notes on Pedal. They all work fine.
• 0:10—Played MIDI Contre Posaune 32’ on held pedal note, then held pedal 1 octave above (note repeating sound).
• 0:20—Changed Ensemble II to Bourdon 16’ and played held pedal note, then held another Pedal note.
• 0:30—Played held note, then chord on Swell w/Ensemble II on Organ MF. Tried different octaves held briefly.
• 0:41—Switched to 32’ Contre Posaune and tried individual held notes (briefly on Swell).
• 0:54—Switched to Great and tried held 32’ Contre Posaune and tried individual held notes (briefly).
• 1:02—Changed Ensemble II to Organ MF on Great and tried held notes there as well.
• 1:05—Tried held chords on Great. Same issue.
• 1:15—Tried drawing a Pedal stop to play with the 16’ Bourdon, and changed the volume on the Ensemble II as I held the note, then played some pedal notes.
• 1:32—Switched the Ensemble to 32’ Contre Posaune and tried changing the volume again to end of recording.

Possible Issues:

• The power supply for the card had only black & red cords, which I soldered to the +5v supply (matching the colors there). I noted, however, that the Bass Coupler card’s power supply had a white cord—presumably a ground wire? Should I use that power supply?
• The wires I connected to the jumper strip (green, blue, & yellow) did not have a ground wire (usually gray). Should I add one?
• The signal cord (input & output to/from cage & USEM card) had 5 wires on one connector, and 6 wires on the other connector. They were originally connected to the Bass coupler, but I just moved them to the MIDI card. The instructions say something about if I have a 5-wire system, that I should cut the blue wire. Could that be it? (It was doing the same thing with the Bass Coupler card in the mix too).

Thanks in advance for any and all help you can provide.

Michael

P.S. OK, I can't upload the recording. I'll put it in my album, and hopefully, the recording will be approved soon. My album link is: http://www.organforum.com/gallery/al...lIDIIssues.mp3

[jbird604]

Goodness, Michael! That doesn't sound very useful musically. I wish I didn't live a thousand miles away and I'd be right over.

What's happening is the MIDI stream is being interrupted at a regular interval, so the grounding of the MIDI selecting wires is not firm. To begin troubleshooting, disconnect the swell, great, and pedal wires from the drawknobs and try grounding them all to a known system ground point such as the bundle of white wires on the AC distribution box in the floor of the organ. If that makes it work correctly, you know that the MIDI card itself is OK.

I don't think you have a power problem because the organ would not play its own stops if the MIDI card were not working and getting full power.

I suspect your real problem is that the drawknobs do not actually "ground" when pulled out as they do in MOS organs, but send some kind of computer pulses. So you must connect the MIDI activating wires to the "REM" outputs on the Console Multiplexer board rather than wiring directly to the knobs.

Check first by grounding all three, and let me know if that makes it work. If it does, I'll see if I can find a chart to guide you in connecting your wires to the REM outputs.

You have my email address, so just send your results to me directly.

John

[myorgan]

John,

Thanks for the reply. I suspected the problem might be grounding, but there wasn't anything to connect the MIDI card to a ground (usually there's one pin dedicated to grounding, I thought). I soldered the MIDI activating wires to the jumper strip (pictured below), and thought that was probably grounded (pins 31, 34, and 36). I look forward to receiving the chart for the REM outputs on the MUX board.

What I also found odd was that the tempo of the repeated tone changed depending on the division (i.e. Pedal was approximately 1 per second, while the manuals were repeated 2-3 per second). I suspect the fact that the amplitude of the MIDI sounds were also affected by the grounding (softer than the organ's stops).

Can't wait to find out how to ground the stops. It was also odd that when I pulled the 16' Prinzipal in the Pedal, that also activated the MIDI, but I suspect that's related to grounding as well.

As always, thanks for your help.

Michael

P.S. I've sent you an e-mail on a related topic.

[jbird604]

I don't immediately recognize the layout of the strip in the pic, but I still suspect that these pins do not actually go to system ground when the knob is pulled. I'll try to find the REM diagram on the Allen site and will email it to you if it's in PDF format. Otherwise, I'll make you some notes about how to connect.

Do go ahead and manually ground all three to the system ground and make sure that MIDI works correctly that way. If it does not, then we have some other issue. I don't think any kind of dedicated ground wire is needed by the MIDI card, as it gets ground via the black power supply wire and through the data cables.

I'll check email in a bit and respond to you tonight if I can find the info you need.

[myorgan]

MIDI Grounding HELP

H-E-L-P!!! Does anyone know how to ground the connections to a MIDI connection? On the card, the 3 wires I connected are in an adapter that connects to the card (between the 2 MIDI cords on the card). On the other end, they are loose wires, that I soldered to the appropriate pin so when the stop is drawn, that particular division sounds. Could you look at the attached photo and tell me where/how I would ground the wires (green, yellow, and blue individual wires at the top of the jumper strip)?

Thanks in advance for your help. I hope to complete this Sunday afternoon, and it's beginning to get cold here. I think I have a limited number of nights left to work in the garage on this project.

Michael

[myorgan]

Well, I tried grounding the pin today. I used a wire to connect the pin connected to the blue-colored wire on the jumper strip to the cage--using the cage as a ground (MIDI Great). The sound became steady, but it turned on several other Great stops as well. Not sure what that was about. Any other place I connected the pin did not work. I wonder if it needs to be grounded to the stop mechanism specifically? Guess I'll find out tomorrow when I try that.

Michael

[myorgan]

Well, the organ is now in a performing space for the next 3 weeks, then back to the garage until December, January, and April (next dates on my calendar for this organ). So, I'll have to put this project on hold until next Spring (too cold in the garage). I was hoping to use the MIDI with the Symphony later this year, but I don't want to mess up a good thing.

Thanks for the input, John. I'll be back in touch about this next Spring.

I recorded a more recent audio example after I grounded the pins, but won't post it because it has my voice on it. I must not have been actually getting ground pins connected because more than one stop was sounding. There are 3 or 4 different connection diagrams for these 4300 organs, and short of tracing the wires directly, I don't think there's enough documentation to figure things out on my own.

Michael

[myorgan]

John,

I've sent you and e-mail about a repair question (hint: MIDI & technology). Hope you see it.

Michael