midifying my old Johannes opus 220

Hello everyone,

I'am an owner of an old analogue Johannes Opus 220. The console etc is still looking very nice, so I would like to midify this console to use it with Hauptwerk.

After reading through this forum, I can come up with two options.

1. Replacing the johannes keyboard for a keyboard controller like the M-audio E-61, and only midify the pedal board
2. Midify the old johannes keyboards by adding reed switches etc.

Since I like the touch of my johannes keys I prefer the option of midifying the existing keyboards.

Can anyone give me advise on how to do this, will it be possible to use the existing contact switches of the keyboard and the wiring attached. My organ is using one main busbar and all the keyswitches are single wired.

I hope someone is able to comment on this

regards

Gertjan de Bruin
The Netherlands

Hello Gertjan

Assuming that you don't want to retain the analogue electronics, you can easily use your existing manuals / contacts / wiring by connecting them to an interface such as the mpc64xr from http://www.midiboutique.com. You'd need one per keyboard, and the smaller version (mpc32) for the pedals (unless you get the same one and use the extra notes for pistons). Other suppliers have similar units, of course.If you want to use the existing contacts and wiring as they are, you need a "scanrow" rather than a "scanmatrix" setup.

Reed switches are excellent for pedals (if you need to replace your contacts) but I wouldn't use them for manuals..

If your console has a single wire / key, then it should be a relatively simple task to reuse the existing contacts (possibly even the wiring) and connect it to a MIDI encoder board, such as available from here http://www.midi-hardware.com/products.html or here http://www.midiboutique.com/

Thanks a lot for the replies,

Since I'am totally new in the Hauptwerk and midi world, I have some more questions.

When I use the mpc64xr and have only 61 keys on my keyboard, does this mean that I have 3 notes left to use as pistons?

Can someone discribe the difference between "scanrow" and "scanmatrix"?

I will check on my wiring later today and maybe make some pictures to show it. Hopefully I can connect the existing wiring to one of those boards quite easily.

Keep u posted

regards

Gertjan

Disregard last about the question between "scanrow" and "scanmatrix", it is clezarly decribed on the midiboutique site.

regards

Gertjan

When I use the mpc64xr and have only 61 keys on my keyboard, does this mean that I have 3 notes left to use as pistons?

Yes, but in that case you need to make sure that the extra 3 switches transmit MIDI data on a different channel than the normal 61 keys, otherwise you won't be able to use the transposer in HW. It is better to keep pistons together with stop switches.

Hello Gertjan,

It is a nice project.

On another forum http://www.klavarorganist.nl/modules.php?name=Forums&file=viewtopic&t=1277
has a member also build his Opus 220 to a hauptwerk organ, but he has replaced his manuals.

Good luck.

gr.
Jeroen

Thanks a lot for all the info,

I read on midi-hardware.com that they can pre-programm a splitpoint so that some notes use a different channel. Will that be an option to use those as stops? or is there another better way to do that?

I'll try to post some pictures of the wiring of my keyboards to make sure that I'll choose the right boards.

Since I'am gonna remove the analogue part anyway, I'll might be able to measure all the wires and contacts of the existing keyboard to see if they are usefull.

Regards

Gertjan

Hello Gertjan

I midi-fied an old analogue electronic organ using the existing key contacts and wiring, in much the same way as you are considering.

I used separate encoders (MidiBoutique mpc64) for each of the manual keyboards and the stop rail, and MidiBoutique mpc40 (now superseded) for the Pedals. Later I added a third manual and some pistons, which required two more encoders. So altogether I have six encoders connected to my computer. Actually, two of them are daisy-chained, but that still necessitates five MIDI inputs to my computer - for which I use a Motu Microlite MIDI-to-USB interface.

I am not 100% happy with this arrangement because the Motu interface is not 100% reliable with Windows Vista 64-bit. Most of the time it works fine, but every so often it fails to operate when I boot up the computer. To fix this, I have to open up my console, and remove and re-insert the USB plug - after which it works perfectly again, for a week or two. It's no "big deal", but it IS inconvenient - and if I were starting again, I would give serious consideration to the "all-in-one" HWce type of encoder, which would connect directly to my computer (soundcard's) MIDI port and eliminate the need for a separate MIDI interface.

In fact, I am still considering the possibility of re-doing my console using the new HWce board, and would appreciate comment from others who have done their own MIDI setups.

Best wishes

Graham

My two cents. I've been satisfied with the MidiBoutique hardware. Photos of the Rodgers 321A are on their web site. The hwce-max scan-row version has handled the three keyboards, pedals, stops, and pistons with room to spare. If I move some pistons to the top half of the pedal channel I'll still have room for second-touch on the accompaniment manual. There are plenty of other choices out there. I'd like to try MIDIbox sometime. The price is right, but I think there's more of a learning curve involved. More roll-your-own versus ready to go out of the box. Anyone have experience with them? The advantage, for the intrepid, would be the ability to do some programming.

If the keyboard has a common bus bar (wire, whatever) that each key makes a contact with, then the scan-ROW approach is the easiest route. Enjoy! There are lots of good threads on this site, some of which point you to very well documented projects.

I am happily using a hwce for two manuals and pedals, plus pistons and stop switches. In the meantime I've also built a MIDIbox project to drive LEDs in the stopswitches. Soldering it together was not a big deal, programming was very simple, and there's a very active community around. On the other hand, if you've never soldered things before, and have no experience with editing config files, etc., then get something prebuilt.

If you want something simple, just get the hwce, it can handle 4x64 contacts, 2 for manuals, 1 for pedal, 1 for switches. It uses scanmatrices, but they also sell a converter to use the scanrow. See the bundle for EUR 200 at

http://largonet.net/midiboutique/produc ... d_id=10302

If your keyboard connections are reliable, then you shouldn't replace them.

Thank you all for the great inputs.

During the weekend I will check out all the keys and wiring, make some pictures and come up with a plan

I'll keep you guys posted on the progress!

Regards

Gertjan

Hello everyone,

Yesterday I opened up my old organ to check-out the details of the keyboard wiring. As expected the upper keyboard (swell) is single wired from the keys and from the busbar.

The lower keyboard (great) is actually different. This one has two busbars on top of each other. Each key contains two little metal springs and when I push the key down, the upper spring touches the upper busbar, and the lower spring the lower busbar. So, two wires are coming from each note, and two wires from the busbar.

Does anyone know if this is done for redundancy or is there another good reason? Why is only the lower keyboard double wired?

If I want to midify my keyboard using the existing wiring can I use the same boards for a standard scanrow setup like the MPC64xr from midiboutique?

I made some pictures of the keyboards, but unfortunately I'am unable to post them here, since I do not have them on a internetsite or webserver.

Hopefully someone can give me some advice on how to midify my old keyboards

Thanks a lot in advance. must say this forum is great, lots of good info and advice.

Regards

Gertjan

Hello Gertjan

The extra contacts could be for redundancy, but I think it's more likely that it's how the Swell to Great coupler operates.
In any case, you can use one of the contacts (or both in parallel) to connect to a scanrow system.

Ian,

You are totally right about the great to swell coupler. I just tested it by removing one of the two contacts from one of the keys and found out that the top contact is for the coupler.

All I need now is one of the midi boards!!

Thanks for you're help

Cheers

Gertjan