ADC-9000: devices on the floor of the console?

[AllenAnalog]

The discussion of speaker switching and multiple amplifiers per cage output channel on MyOrgan's ADC-8000 (in the Allen Owner's Group) got me wondering how Allen connected them. If the amps were at some distance from the console and/or in two different locations, some kind of distribution amp with line drivers would be seem to be the more likely design.

So that got me to wondering what function the four silver boxes with multiple white labels and the two nearby devices on the floor of this ADC-9000 console were for? They seem to be connected with the gray cables used for audio in ADC consoles. Are these units distribution amps/line drivers - used in large installations? Or something totally different?

[Organkeys Jones]

I think they are nothing but screw terminal strips. The aluminum cover may just be shielding. I've seen about as many organs with the cover as those without a cover. I'm not aware of any electronics under there.

[AllenAnalog]

What would you need that many screw terminals for? There are no amplifiers in this console.

[you795a]

That's all that should be under those metal covers, Barrier strips with screw terminals. Those covers are used to shield against hum., They still used the same covers when I worked there.

[Organkeys Jones]

Larry, there would be a terminals for every channel. And that organ has a lot of channels! From those barrier strips, the audio would go to the amps on external racks through coax cable. For organs with internal amps, similar barrier or terminal strips would carry the amplified signal and would be the connection point for speaker cable.

[myorgan]

Larry,

I think perhaps the key to what they are is on the covers of the boxes. The labels are on both sides (with one exception), and there are 24 of them. I suspect the one without one side labeled corresponds to the short cage, and the other 3 correspond to the larger cages.

The 6 Trem-III boards make me wonder if Vibrato was standard on all of the multi-cage organs as standard equipment?

Thank you for sharing the photo, Larry. It's a "heads up" of what I'll be getting myself into later this year.

Michael

[michaelhoddy]

I forget if there's any kind of buffer circuitry in there or not, but I'm pretty confident those are just the junction points where the internal gray RCA unbalanced audio cables junction over to F-style connectors and RG59 CATV-style coax for the signal runs out to the remote amp rack(s). I've seen quite a few larger ADC Allens with this configuration- RG59 is a unique, but definitely very workable choice there for long, shielded signal runs over distance with good performance and moderate cost. In the picture shown, the RG59 runs are disconnected.

[AllenAnalog]

So that still begs the question of what happens when you have two or more amplifiers on a given cage output channel and those amp racks are located in "chambers" that are some distance away from the console and each other. I can't believe they just used RCA "Y" connectors to parallel the amp feeds.

[Organkeys Jones]

Sure they did. I saw that on an ADC custom recently that had double amps. One coax to the first amp, "Y" RCA to the second.

[AllenAnalog]

But how close together were those amps? Would they really have done that if the amp racks were on opposite sides of the church from each other and 150 feet away from the console?

[myorgan]

Larry,

How far apart are the "opposite sides of the church?" If they are within 50' of each other, RCA would suffice, but if it is further, perhaps they would Y-split the RG59? I have never seen it personally, but wouldn't be opposed to trying it if necessary.

Michael

[otispit]

Our 9000 has the signal split at the amp rack. One speaker complement is just a lot farther from the amp rack. It's riskier to send the low level signal long distances than a speaker level signal....RF interference? The preamp level signal seems adequate to drive more than one amp...not sure if impedance mismatch might alter the sounds though....it shouldn't. That might be more of a problem with two long low level signal cables than dividing right at the amp rack.

[AllenAnalog]

Nice to see you posting on here again. How about an update on your 9000 installation? How did it turn out?

[otispit]

Sorry for the abrupt end to my posting in August of '17. Long story, but while climbing out of the chamber after adjusting speakers, a ladder collapsed, I fell 30 feet, needed 15 hours of surgery to put left shoulder and right wrist back together. Did not return to my school orchestra job until the second week of December...70 work days---casts on both arms!!! My sub took instructions by phone and had the kids ready in Dec.....performed a 2 hour Messiah, and the next week our Holiday Showcase with 120 member symphony and 80 voice chorus....they were fabulous. I was lucky to be alive..fall to concrete, ladder went through window...luckily head only slightly bumped as my poor shoulder took the brunt....then ladder smashed wrist. I guess I said some choice words on the way down for the little old daily mass ladies!!! Long recovery, but 95% now.
Anyhow, the project remains partially finished since during my recovery a new 'remodel priest' moved in resulting in 2 years of limbo. Everything plays and the 9000 sounds great, but I'm not doing anything until the building plans are finalized.....or. hopefully cancelled. Sang 'virus masked' tonite in a trio accomp by organ.....still a beautiful thing, if not my final vision.
Our current project is trading in this music hating priest!!!!! New bishop might be our ally.
BTW----if you have heard anything about the Bishop Elect of Duluth withdrawn because of abuse allegations---THAT WAS OUR PASTOR FROM 20 YEARS AGO!!!! Another organ hater!!! Karma!!!!!
And yes....those plates just cover the line level terminals that use coax to the ADC amps.

[myorgan]

So sorry to hear of your misfortunes! I'm glad you're back up and running now, as I've been in your shoes and know how long it can be to recover. Let us re-read the thread to get back up to speed on your organ before we respond.

Glad to see you back.

Michael

[Organkeys Jones]

I can't believe that happened to you! I am so sorry!

[AllenAnalog]

So glad to hear you are getting better after that terrible accident. Thanks for the update, I've been concerned that we did not hear any more from you about this wonderful project. Best wishes for a change in church leadership.