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I want to MIDIfy a 60s vintage analogue console with multi-wire contacts on keyboards and stops. I am gutting out the original vacuum tube tone generators. My original plan, based on seeing the pedal board contacts, was to use midi encoders with 61/32 switch inputs and wire them straight on to the keyboard/pedal/stop switches - like one of these from Midi Boutique or Midi-Hardware
The one from MB looks especially good because it can be configured to use up to 36 volts on the contacts.
However, now that I have dismantled the organ enough to see the keyboard and stop contacts, I was surprised to find the contacts are normally closed (the pedal board's are normally open). Is this common? So I'm guessing this means I can't use the MH board which seems to require NO switches, and I also can't use the active keying voltage feature of the MB boards?
I'm still keen to use the original switches but if it proves unreliable I assume I'll be getting ciphers which would make the organ unusable. So if I then go with new switches (reed/hall/optical) I'm thinking that optical switches might be easiest to fit using the brass switch wipers on the keys as shutters to interrupt the light beam. But I haven't been able to find any circuit examples of how you would use optical switches in a keyboard (feel free to point me in the right direction). Is it possible to still use bus bar style midi encoders with optical switches or would I have wasted my money and have to start again? Thanks.
The one from MB looks especially good because it can be configured to use up to 36 volts on the contacts.
However, now that I have dismantled the organ enough to see the keyboard and stop contacts, I was surprised to find the contacts are normally closed (the pedal board's are normally open). Is this common? So I'm guessing this means I can't use the MH board which seems to require NO switches, and I also can't use the active keying voltage feature of the MB boards?
I'm still keen to use the original switches but if it proves unreliable I assume I'll be getting ciphers which would make the organ unusable. So if I then go with new switches (reed/hall/optical) I'm thinking that optical switches might be easiest to fit using the brass switch wipers on the keys as shutters to interrupt the light beam. But I haven't been able to find any circuit examples of how you would use optical switches in a keyboard (feel free to point me in the right direction). Is it possible to still use bus bar style midi encoders with optical switches or would I have wasted my money and have to start again? Thanks.