Help with A-G Praeludium audio

[m&m's]

I know that there is a veritable encyclopedia of knowledge and experience, and I need some of it. I just bought an Ahlborn_Galanti Praeludium III, about twenty years old, from a fellow who had it in his house, having bought it from a church that, well, you know the story, went for keyboard, praise music, etc. He was listening to it through headphones, not having speakers (they stayed with the church!), although he did get the seven stereo amps.

My question is, what do I have to do to get the organ playing through these amps? The hookups for the amps include a relay input, presumably to turn the amps on when the organ is powered up, and then to simultaneously shut them down. Any ideas?

PS. This is a wonderful sounding organ, even just playing through a stereo hifi amp and two speakers, much better sounding than the Allen MDS organs of that era. I know, because I have an Allen MDS 317 sitting beside it in my music room. (No, I don't want to start a fight!)

[seamaster]

Wrong subforum, mate. We have no idea what an "Ahlborn_Galanti Praeludium III" is.

[andyg]

Moved to the correct sub forum. Home Organs is for entertainment style electronic organs. We appreciate that some people have classical organs at home, of course - some members have theatre pipe organs but they don't go in Home Organs either!

[michaelhoddy]

Those are hot-rodded Carver WM200 amps that were modified by Walker Technical. We installed a lot of them with Praeludium organs, and it's almost certain that the organ in question was originally sold with Walker speakers. (I saw that organ that you must have acquired on eBay and was myself interested in it!) It's not a complex matter to get this all up and running if you're moderately comfortable with soldering. It's possible to do it with pre-fab cables and connectors, but a lot neater to do it with raw cable and connectors.

You're going to be using 1/4" TS phone plugs running over shielded 2-conductor (or 3-conductor) cable to spade connectors at the amps for audio, and a coaxial DC power connector, also to 2 spades for the relay, which we usually just jumped parallel from amp to amp since it's just a contact closure. All the connectors live in the back on the organ under a hinged cover at the lower right, so you don't even need to take the back off for access.

Before I go further, how many speakers or channels do you intend to connect? The PIII can run with as few as 2 and as many as 16, and automatically splits out channeling depending on what's connected to it.

It has diatonic C-C# outputs for each channel pair. Those can be All C-C# (2 channels), All Flues C-C# and All Reeds C-C# (4 channels), Each Division C-C# (8 channels), or Each Division Flues and Each Division Reeds C-C# (16 channels). There are of course an infinite number of other variations on this (such as breaking out just the Choir reeds to give the big solo trumpet its own channels), but the above is how most of the organs were installed)

[m&m's]

Moved to the correct sub forum. Home Organs is for entertainment style electronic organs. We appreciate that some people have classical organs at home, of course - some members have theatre pipe organs but they don't go in Home Organs either!

Thank you. I wasn't sure where to start this thread.

- - - Updated - - -

Those are hot-rodded Carver WM200 amps that were modified by Walker Technical. We installed a lot of them with Praeludium organs, and it's almost certain that the organ in question was originally sold with Walker speakers. (I saw that organ that you must have acquired on eBay and was myself interested in it!) It's not a complex matter to get this all up and running if you're moderately comfortable with soldering. It's possible to do it with pre-fab cables and connectors, but a lot neater to do it with raw cable and connectors.

You're going to be using 1/4" TS phone plugs running over shielded 2-conductor (or 3-conductor) cable to spade connectors at the amps for audio, and a coaxial DC power connector, also to 2 spades for the relay, which we usually just jumped parallel from amp to amp since it's just a contact closure. All the connectors live in the back on the organ under a hinged cover at the lower right, so you don't even need to take the back off for access.

Before I go further, how many speakers or channels do you intend to connect? The PIII can run with as few as 2 and as many as 16, and automatically splits out channeling depending on what's connected to it.

It has diatonic C-C# outputs for each channel pair. Those can be All C-C# (2 channels), All Flues C-C# and All Reeds C-C# (4 channels), Each Division C-C# (8 channels), or Each Division Flues and Each Division Reeds C-C# (16 channels). There are of course an infinite number of other variations on this (such as breaking out just the Choir reeds to give the big solo trumpet its own channels), but the above is how most of the organs were installed)

I'm glad I grabbed it before you did!!!!!

I figured someone on the forum would know what I needed. I know how to handle the channels, and will probably use about ten of them. I presume that, for instance, if you plug into the Swell Reeds, those channels are disconnected from the all purpose main Reed channels. My real problem is, what do you do with the relay? Where do you plug that in, and/or how?

[michaelhoddy]

Yes, anything you plug in directly gets subtracted from the "main" channels, whether it's the overall pair, or the divisional main pairs if connected.

It's been years since I looked at the terminal strip on a Walker-modified Carver WM200, but I believe there's a pair screw terminals all the way to the right for the relay. They should be labeled as such, or with terminology (remote?) that means the same thing. All you need to do is connect these to one of the two coaxial relay plugs on the organ's output board next to the audio outputs. There are two relay outputs on the organ, but they're just duplicates. Polarity doesn't even really matter here, as it's just powering the coil on a relay in the amp with 12 volts DC. If you are using multiple amplifiers, you can just parallel the relay terminals with jumpers and connect each amp's relay to the preceding one. Any 20-gauge or similar wire is fine for the relay- we always just used a pair of the same cable as for the audio signals.

The relay outs on the organ look like this (except for the panel nut):

https://cdn.shopify.com/s/files/1/09...g?v=1446836450