Allen ADC-8000-DKC Project

[John Kinkennon]

It appears I'm on track to purchase an Allen-8000-DKC that popped up on Craigslist Portland this morning. I've offered the $1500 asking price as I've been watching for something like this to show up for a couple of years. Recently a similar console showed up and was spoken for that same day.

I've also been waiting for the opportunity to reverse engineer the multiplexed keystroke info from an ADC so I may be asking for some pointers about where to locate that signal.

Whether this will be a project for resale is up in the air. I really envision keeping it to the extent that I'm looking into the cost to replace a front door with side panel or the cost to have a carpenter remove and replace what's there. So I'm really happy about the prospects and think this might be a project to document more thoroughly than usual for everyone's enjoyment.

EDIT: 22 speakers, mostly HC-15s and a few subs. I have a Hauptwerk friend who modified his HC-15 speakers with a new midrange driver, a treble horn, and a Parts Express crossover. Any preferred mods? Old units I tried a few years back seemed to have a muddy sound but I suspect they could be brought back to life.

[jbird604]

Holy cow! $1500.... Sounds like a steal to me. Of course there are many folks who would be delighted to have that organ just as it is, and some have paid a LOT more money than that for one. I think you'd be fully justified in taking off the door to get that one inside.

As to modifying the HC-15, I haven't heard of that being done. I generally consider that to be one of the best general-purpose organ speakers ever built. If you heard some that sounded muddy, it's more likely to have been either a voicing issue or else the tweeter controls are turned down too low. But then, some folks may be looking for a different kind of sound.

[toodles]

I did a frequency sweep test of the HC-15 years ago using the tibias of an MDS Theatre III Iin my living room and a Radio Shack sound meter--not the most scientific of tests, but it generally showed a fairly flat frequency response.

I am with JBird on the HC-15--it's hard to find a better general purpose organ speaker than it. The Peerless midrange is quite flat in response, and the tweeter is a good one. People who modify it as you suggest probably want a hot high end, not a flat one.

My recommendation is to tailor the sound in the generation process, not at the speaker.

[John Kinkennon]

Thanks for the advice about the HC-15 speakers. I have the REW software so I'll make a point to run a test on one of the speakers and hope I'll see good results. It is entirely possible that the four I tried earlier had aging crossover components or driver issues. Looking forward to trying a multichannel Hauptwerk system so I may be pleasantly surprised.

The only other issue with the console is that the top manual is not working. I'll clean connectors and reseat boards before drawing any conclusions about the possible repair expenses. If it is possible to preserve the electronics without huge expense then I'm reasonably certain I can create a hybrid Allen/Virtual Pipe Organ with the benefits of both. I've interfaced with the Allen capture system many times before so feel relatively comfortable trying this.

Best of all the console is extra clean and free of all but a few scratches and shows no fading of the custom finish. It's a lighter more golden oak than what shows in the photo. Having 98 drawknobs will allow custom engraving to match one of the larger Hauptwerk sample sets -- I'm thinking of the Goerlitz at the moment which has 87 speaking stops. I'm glad there are others who don't think I would be crazy to replace my front door. The living room isn't huge but it does have a sloping ceiling and opens to the entry, hall, and dining room in a complex enough manner that standing waves have never been an issue.

[John Kinkennon]

I have felt better and better about this ADC-8000 acquisition. With all the help I'm getting, especially with lowering 22 speakers down from a challenging location, and with 3 PA speakers tossed in, I've gone 1/3 higher on my offer with no regrets. I've moved two consoles into storage and cleaned up the trailer and added E-track rails and cargo straps to improve the tie down options. Wednesday morning we do the move and I will try to remember to take photos.



Ha, ha! Wide angle. It's only a 12' trailer. Looks longer in the photo.

[John Kinkennon]

I had two consoles stored on the trailer. So they needed put in a storage unit just to be able to use the trailer.

Yes, Michael. The ADC vintage is where I draw the line, especially for this large an organ. I will try hard to preserve the existing electronics and sound so that either the original Allen can play or it can be switched to play Hauptwerk. This would be very useful both as a comparison and as a backup on the day one or the other of the systems doesn't boot up and play. I'll keep all of you informed.

[myorgan]

John,

Great idea about the comparisons between the two sounds. I just heard a recording of an ADC-8000, and was quite surprised at the realistic sound I heard coming from the Choir ____flötes. My immediate reaction was surprise that they had sounds that good back in 1983 when the organ was made.

I look forward to hearing the comparison recordings!

Michael

P.S. I wonder if you could add a 4th manual above the Swell so you could play some of the larger Hauptwerk sample sets?

[michaelhoddy]

Michael, I think it's a mixed bag with the ADC-8000 sounds. Of course, in a big enough room with full audio, the thing puts out a terrific amount of sound in full ensemble, and can sound quite spectacular if the acoustics are good. Individual sounds though, the only really "special" ones are the Swell and Choir flutes, which have more resources dedicated to them and have realistic chiff built in. The mixtures are all nice, some of the reeds, and the Swell strings with the celeste tuning engaged. Many of the rest of the reeds and the non-articulate principals and flutes are very blah. I've contemplated the same conversion of the ADC-8000 at my church for this reason, knowing that a VPO could make wonderful use of the 30 speakers in place there.

[John Kinkennon]

The organ is finally in the garage and 22 HC-15 speakers plus 4 HC-12s are in storage. Had to post a photo before getting started on more serious evaluation and planning.

[myorgan]

John,

Or the 14th channel could be sub-bass. The 32' stops are on a separate card, but I can't remember if it's a different channel or not. I assume you have the service manual, including cage chart for that organ?

Michael

P.S. I see your Choir division has Vibrato. If you have the trem generators for that division, the E-Proms may be different for that division. I have the E-Prom numbers for both the theatre version, and classical version of that division.

[michaelhoddy]

John- 13 channels is the correct number if you don't have the Brass Choir option in the Swell, which accounted for the 14th channel (2 cages x 7 channels) in the second cage. Since it seems you had HC12's for the pedal channels, there likely would be no subwoofer crossovers and dedicated subwoofer amp channels involved here, instead just regular doubled audio.

[John Kinkennon]

You guys are correct. It's 7 outputs on the first cage and only 6 on the second. I believe the HC12s were for the pedal as mentioned. I have some huge subs with 4 15" woofers if the console ends up in a church. For the living room my Rythmik Audio HP15 is a better choice.

[toodles]

A very handsome console!

[John Vanderlee]

Wow, what a steal! I thought I did great with the ADC5400 with 14 speakers for $1100. Hope for all of us that more bargains like that show up! On the other hand it's sad to see a church put so little value on these things. Is it a reflection of the music taste? I'm curious as to why it was discarded.

[myorgan]

Ironically, John, you probably aren't called to churches who don't use their organs because they have no interest in a working, well-maintained organ. Imagine some of these churches who have pipe organ façades staring them in the face each Sunday, as they ignore them and cover them with projection screens.

I'm sorry for taking this thread on a tangent, perhaps we'd better stick with the OP's topic.

Michael

[jbird604]

Yep, this is a rabbit hole for sure. It's just so unfair that perhaps hundreds of excellent organs are languishing in churches that won't use them while other churches and organ players and lovers are desperate for good instruments.

[michaelhoddy]

JBird, is that the R-280 I seem to remember? What a nice organ. Shame.

[John Kinkennon]

Not much to report except that the capture system works and needs the batteries replaced. That's all good. I was texting with a friend about the difficulty of handling two capture systems and had a breakthrough on how to allow either the Allen OR the Hauptwerk capture system to be operative with a simple mode switch. That and enabling a quick and simple change to the audio routing has been keeping me busy just theorizing at this point.

For audio it would be great to get all 26 speakers repaired which means re-coning all the midrange units. I'll get to that eventually but will initially do some tests with my 10 Behringer 3031As, the ones with the ribbon tweeters, and the Rythmik Audio HP15 sub. My initial thought is to run the 13 Allen signals as inputs to my Focusrite Scarlett 18i20 while the HW signals arrive the virtual route as DAW inputs from the computer. So far I'm just looking to load either an Allen mode file or a Hauptwerk mode file for the interface.

For all else it's just a matter of sensing the state of the HW controls and either follow (read) the Allen matrix for key values or figure out how to read the data line(s). I'm at the point where a hybrid Allen/Hauptwerk combination looks straightforward (it never is). I may let them "play together" but that isn't a priority. Restoring the Allen would just be a matter of cutting away my wiring and possibly needing to reconnect all the green SAMs wiring where I insert a circuit to decide whether Allen or HW gets to switch the SAMs.

[you795a]

I'd be interested in hearing about how the mode switch for the Allen or Hauptwerk capture would be designed.

[Admin]

Bypass the DM board entirely and interface the sense, control, and piston inputs to the MIDI micro-controller. Allocate non-volatile RAM on the controller to store the Allen combination settings. The Hauptwerk combinations are stored in Hauptwerk. Implement a mode switch. When in the Hauptwerk mode the combinations are controlled by MIDI messages to and from Hauptwerk. In the Allen mode, the controller reads the pistons and pulls the combination stored in NV Ram.

This is basically how my no longer available Zuma MIDI Stop Controller DM replacement board works. As an added convenience, it automatically switches between Hauptwerk and internal combination settings based on whether it detects Hauptwerk MIDI messages. On start-up it defaults to its internal memory and assumes that Hauptwerk is not present. If it any time it receives a MIDI message from Hauptwerk, it switches to the Hauptwerk mode.

John Kinkennon already has developed software and hardware interfaces that operate DM era stop controls from Hauptwerk. Implementing some internal storage and a mode switch should be a piece of cake for him.

[myorgan]

Insider secrets. I love it!

Michael

[John Kinkennon]

As always the info is very much appreciated. Backing into this stuff without documentation is a pain. I was just checking on the combination of the key matrix's into a single 16x16 I think. I would love to have a message from anyone who wants to give me a hint about the data cable though at this point I'm content to go directly off the matrix. I won't know more about the swell today -- I'll borrow a mixer to monitor most of the outputs as mine is loaned out to a church for their live streaming. Don't want to hook up a ton of amps and speakers just yet!

[John Kinkennon]

Here is a fortuitous mistake that made me glad I hadn't thrown out a mistake I made last fall. I ordered 30 PCBs fabricated and soldered from JLCPCB in Hong Kong. These are 32in32out I/O expander boards. In my haste I failed to specify a set of 8 pull-up resistor packs correctly and received 30 boards that were missing the one part too small to solder easily. I reordered them correctly and fortunately did not yield to the temptation to toss the first set in the trash.

So what do I now need? 32in32out boards WITHOUT pull-ups as the Allen circuits will already have them and I don't want to load someone else's circuits unnecessarily. That put a smile on my face!

[myorgan]

I'll have to tell my wife about this cautionary tale! She thinks I keep to much "crap." I have to keep explaining why I keep certain items.;-)

Michael

[John Kinkennon]

More good news! There is audio out of all 13 jacks on the card cages. I hooked up a mixer to one cage at a time as I only had 7 cables handy. Everything seems fine and all three manuals and pedals are playing so I don't believe there is a thing wrong with the console. I didn't exercise every stop and coupler but fiddled with most of them figuring out which sounds were routed out of each port. If there is a stop or coupler not working I didn't stumble across it. Sounds were decent and probably will sound quite nice in a large room or with added reverb.

I will take Admin's advice and not try to use the Allen capture card (DM?). I've built a capture system for a Moller organ so that's really nothing new at this point. Just combine the stand alone capture used for the Moller with the HW capture commands taking precedence when HW sends the Organ Ready signal. The general pistons can be wired separately from the toe studs for 20 unique generals. There can be the usual A & B memories or many more for that matter.

So I'm about out of excuses. It's time to get the PCBs wired up and ready to mount where the DM board is now.

[myorgan]

...I only had 7 cables handy.

Are those Jerrold ended cables, or other spade connector cables? If they are Jerrold, I'm very interested in how/what you use to manufacture the missing cables, as I've never worked with Jerrold connectors before.

Michael

[Organkeys Jones]

To Michael, myorgan: ADC cage audio outputs are RCA, as well as the Allen mixers and the ADC amp inputs.

[myorgan]

Sorry, I was referring to the connection between the organ and the amp rack. Mine has Jerrolds, so just checking. I still haven't sorted them out yet. (hides head in embarrassment)

Michael

[John Kinkennon]

Here are all but one of the MIDI boards to do the entire conversion for Hauptwerk. The long brown terminal board is the existing Allen termination for pistons, toe studs, and other capture system related signals. The Allen capture board and a pair of small reversable piston boards have been removed. The 8 green boards are my designs with the encoder at the bottom left mounting a Teensy 3.6. Above the encoder are two small adapters to convert SPI signals from 3.3v to 5v both for compatibility with the Allen key matrix and because I like to operate the stops at 5v through a 1k resistor to match what Allen does. The first SPI channel connects to the long 64 input board to connect the 62 pistons and toe studs and then connects to a 32 input board that will be located close to the manuals. The second SPI channel connects to the four 32 input 32 output boards which each handle 32 drawknobs or couplers.



Ideally one could redo the four stop boards with edge connector pins (slots?) which would mate with the connectors already on the cables as Admin did with his Zuma capture board. I'm avoiding that for now to minimize costs plus this is something I've not yet learned to do. That would make for a much more user friendly install. For now I will solder the connections.

We are looking forward to a pair of 100 degree days here in the Vancouver, WA area and I'm thinking this will be a good time to stay out of the garage and focus on publishing all the documentation to order these boards all fabricated and assembled. All that needs added are the through hole connectors if desired. These boards are VERY affordable if ordered from JLCPCB in Hong Kong.

[samibe]

Would it be possible to have five small boards ordered from JLCPCB with the gold plated fingers on one side and a pin header, ribbon cable or some other connector on the other side that can be soldered to the midi stop boards?

[Admin]

samibe Thought about that, but not much savings for a whole lot more wiring complexity and customer handholding.

[John Kinkennon]

It's the support aspect that keeps me from actively selling MIDI boards. I lend a hand helping one or two people at a time when their project or their interest level gets my attention. My focus is to get as many projects documented as possible in order to benefit those with electronics experience or enough initiative to do some self study.

[John Kinkennon]

Wiring is in progress with the pistons soldered in except for the couplers and a pair of Tutti pistons. That's the row of white wires in the center of the photo. The first group of approximately 32 stops are being moved from an edge connector with 7 or 8 done so far which will be enough to run some initial tests on the capture system.

The present encoder utilizes the Teensy 3.6 development board. I've held off on providing documentation for that as there is a new encoder PCB arriving Friday that will use the Teensy 4.1. The 4.1 at 600 Mhz is hardly necessary, my earlier encoders ran at 40 Mhz. However, I have plans to experiment with MIDI over ethernet and the 4.1 has the ethernet PHY onboard as well as 64k of flash reserved for EEPROM emulation which will serve as storage for a lot of capture memory. How about an Allen ADC-8000 with a sequencer built in? Overall the Teensy 4.1 is an amazing product at a few dollars less than the 3.6!

[John Kinkennon]

DHL brought the package of 20 PCBs three days early so I changed plans and set up two encoders using my Teensy 4.1s. They seem to be just right on the first try though I haven't exercised every feature. I only have the SMT components mounted by the factory so it went like this:



The PCB provides connectors for 8 potentiometers where the straps are inserted, 2 SPI channels at the upper right, 2 serial connectors for serial enabled LCDs, and 16 open collector outputs along the left edge for various lamps or LEDs, relays, and the four control inputs to the Allen capture supply. The USB-MIDI connector is at the top of the Teensy 4.1. Will get this board swapped into the organ console tonight of in the morning.

EDIT: Whoa! I enlarged the third photo and I have some carelessly soldered pins on the Teensy 4.1. My bad, I'll fix it soon.