Need advice on wiring Conn pipe speakers to a Conn 550

[EricS]

I am new to the Organ Forum, so let me compliment all you good folks who contribute and provide lively discussion. I recently became the proud owner of a Conn Model 550 Theatrette. My first organ, although my wife plays a Roland digital piano KR 577. I do some elementary repairs to our church pipe organ, a Schantz 2-manual.

A bit of background on the 550. It was sitting in a thrift store looking forlorn, but with a great walnut cabinet and even the matching bench was flawless. So my ever-thoughtful wife bought it for me and had it hauled home. As I explored the instrument, I found that it apparently sat in someone's living room for about 40 years, where it did not see much traffic or playing. Hence the excellent cabinetry. Howver, the contact wires and bus bars were highly tarnished and corroded, and only about 40% of the notes would sound. I have painstakingly cleaned each contact and busbar, and it is now almost 100% playable.

Just last week I also purchased on e-bay a set of Model 144 pipe speakers. They arrived over the weekend. I am now puzzling as to how to hook them up. Inside the back of the organ cabinet is the speaker amp, labeled "Model 51 speaker". It has three plug receptacleson top and one on the side facing the back of the organ. The ones on top are labeled, and the one on the side is labeled, "External speaker".It is round and has slots for six (6) pins, and the pin slots are labeled 1-6. Iam NOT an electrical engineer, and do not know much about wiring at all, and nothing about speaker wiring. But I am a chemical engineer, so with some guidance from you good folk should be able to carry out your instructions. After reading several threads on the Organ Forum, I wonder ifwhat I describeis a six-pin Leslie plug receptacle. If so (or even if not), how do I proceed to wire in the Model 144's?

Any advice will be greatly appreciated.

Bythe way, my ultimate ambition after getting this organ and its service manual is to own a Conn Model 650 or 651 or 652. But that'll have to be for another time...

Thanks for any advice you can offer.

[Royal]

Re: Need advice on wiring Conn pipe speakers to a Conn 550



EricS, Welcome to the Forum. I too am a relatively recent Forum member and am quite happy with my Conns. I started out with a Theatrette 552 but before I could pick it up, stumbled across a 3 manual 580 and just couldn't resist. My setup is with a 145 Conn pipe system and a 700 Leslie and I think it sounds terriffic. The pipes added a touch ofbrilliance and they look great. I think that I heard some other forum member describe the setup with pipes as "empowering", and I agree.I got a lot of very good advice from member Lajko. Lookfor a thread under"rebuilding Conn pipes". Lajko knows far more than Ibut I might add a few things to his list: First, it is very likely that there might be debris (dead mice, marbles, hot wheels etc.) inside the pipes resting on the speaker cones. I would highly recommend that you carefully take the system apart and clean the tops of the speakers off before testing on the organ. Second, a word about the hookup on a 552 (which I believe is identical electrically to a 550): These pipes are fed by the console amplifier complex (non tibia) channel. Looking at it from the back, it is the one on the left. The hot wire to the speaker goes to a switch that is mounted at the keyboard and allows the selection of either console or pipes or both. Then two wires from the switch one going to the console speaker and the other to the pipes. There should be a resistor to keep the proper load on the amplifier regardless of switch position.

I

[Royal]

Re: Need advice on wiring Conn pipe speakers to a Conn 550

EricS, I forgot to mention that organservice.com has a Pipe connector kit with clear instructions that you can use to hook up. I had rebuilt my pipes with the installation of a woofer and a tweeter as Lajko had suggested and liked the results for not a lot of money. Roy

[Guest]

Re: Need advice on wiring Conn pipe speakers to a Conn 550



I have added pipes to a 651 that I installed at a senior center.I have the user manual and the service manual with all of the schematics.

One surprise was seeing the schematic of the pipe interface in the Conn 651 manual. All it did was connect the pipes in parallel with the other speakers. You had a switch for console, both (which then was in parallel) or pipes only. The was a small pot to adjust the volume of the pipes, but basically it connected everything in parallel. There were no loading resistors to balance the load on the amp and keep it at 8 ohms.

So just connect in parallel - and please read on regarding cross over networks.

Since the 651 had a 6x9 and a larger speaker for the complex channel and no crossover, (again they were in parallel, but the tibia channel did have a minimal cross over, I don't have the schematic in front of me this late at night) I added a crossover network. That helped a lot. Then I added the pipes in parallel out of the crossovers as that helped keep a decent load on the amp. Then I boosted the complex channel, made the trem a little heavier and faster and WOW!. A 145 set of pipes to the highs and a 146 to the bass on the complex channel (with the cross overs added). That really made the pedal have lots of oomph! Also the 146 set had all 4 speakers replaced with 6x8 woofers from Parts Express at about $60 each.

146's have the same speakers, in fact ALL pipe speakers were made with the same 6x9 speakers, so the big 146's weren't really that great for bass unless you replaced them with woofers AND/OR close off that cosmetic notch with tape. Then you really get nice pedal bass. We know what a hole in a pipe does - it raises its resonant frequency and that's what those cosmetic notches on the 146's did so you really should close those off if you want them for good, soft, pipe organ type bass.

At least in the 651, the Tibia channel has a cross over so the highs go through the Leslie and the low do not because (as the service manual says) the low frequencies have a wave length too long to have any effect by the rotating Leslie.

So how to connect? Since Conn did it in parallel, do it that way. Get cross-overs where Conn left them out and it will improve the sound.

[ptbuzzcut]

Re: Need advice on wiring Conn pipe speakers to a Conn 550

I don’t know if the 550 is anything like my 650, but on mine, this is the setup. On the amp chassis there is a round plug. The pipes have an 'interceptor' (that’s what it is called)that gets plugged in here and the plug that would normally be in the socket gets removed to accommodate the interceptor and plugged into the top of the interceptor. There are two grey wires that are fed through the console to the switch mounted underneath the right hand side lower keyboard.The switch controlsthe sound, whether organonly, pipes only or both. The grey wire is attached to two terminals on the underside of the switch. I do not have pipes, but the organ is setup for it. They may have been sold before I acquired it (also looks like a Leslie connector set was left in place for a model other than the Conn 251). From what I have read in researching what I need to do after I get a set of pipes, one thing kept ringing true. The speakers for the pipes need to be wired in parallel and an 8 ohm load maintained. Don’t know if this is true, but just passing that on. If you need a picture of the amp with the interceptor, I can accommodate that as the back is currently off the organ.

[Guest]

Re: Need advice on wiring Conn pipe speakers to a Conn 550



This part of my posting is referring to the schematic for the interceptor connector/device:

One surprise was seeing the schematic of the pipe interface in the
Conn 651 manual. All it did was connect the pipes in parallel with the
other speakers. You had a switch for console, both (which then was in
parallel) or pipes only. The was a small pot to adjust the volume of
the pipes, but basically it connected everything in parallel. There
were no loading resistors to balance the load on the amp and keep it at
8 ohms.

Since I didn't have the "interceptors", I simply added connectors off of the speakers to go to the pipes.

[crossyinoz]

Re: Need advice on wiring Conn pipe speakers to a Conn 550

[quote user="EricS"]


I recently became the proud owner of a Conn Model 550 Theatrette.

Just last week I also purchased on e-bay a set of Model 144 pipe speakers. They arrived over the weekend. I am now puzzling as to how to hook them up.

Inside the back of the organ cabinet is the speaker amp, labeled "Model 51 speaker". It is round and has slots for six (6) pins, [/quote]

G'day Eric,

The 6pin socket you see marked "51" is for a Leslie speaker, "51" or the later 251/351 being the Leslie model numbersyour organ is already wired to accept.

Conn pipes came in 3 different models, your 144 set differs from the other two in that its speakers are 16 ohm impedance, the others being 8 ohm, something you should be aware of when making your connections.

Cheers,

Ian

[Guest]

Re: Need advice on wiring Conn pipe speakers to a Conn 550



As noted, the Conn pipe speaker connector kits just connected the pipes in parallel to the regular speakers on the complex channel. You can solder in or use push-on connectors and come right off of the speaker. Being 16 ohms for a 144 model, it won't be as loud. You can rewire it for 4 ohms as there are 2 - 8 ohm speakers in it. You could replace both speakers with new speakers. About the only ones available in 6x9 are car speakers which are 4 ohms so you would be 8 ohms wired in series. (Watch out for ones with tweeters sticking up on a post in the middle. Most of those are too high to fit in the pipe box and also check for speaker depth - some are too deep to fit.)

Back to connecting them: You could just connect in parallel OR better yet, you could get an 8 ohm L-Pad. That would divide the load and allow you to control the balance between the internal spealers and the pipes. In doing that, you might want to turn up the volume of the complex channel and/or turn down the tibia volume a little for better balance between them.

[EricS]

Re: Need advice on wiring Conn pipe speakers to a Conn 550



Thanks to all who have weighed in on this topic. A new development has come up that is changingmy entire "organ"-ization. I am about to purchase a Conn 651 and have it shipped to me. Therefore, I plan to wait until the 651 arrives to do any pipe speaker hookups.

Folks, this organ bug really bites you, doesn't it? I went from having no electronic/theatre organ three months ago to now having potentially two in my basement office/music room.I likely will donate the 550 to a local senior center, but for now am enjoying the anticipation of a real three-manual full-size theatre organ with AGO concave pedalboard.

Anyone have any thoughts on the 651? I have read several blogs that indicate that this is one of the last really great Conns. The one I am purchasing has been thoroughly rehabbed within the last year by a licensed organ tech, and is reputed to be at 100% perfomance.

Again, thank to all who have helped me understand the speaker wiring setup. Keep the info coming!

EricS

[OrgansR4Me]

Re: Need advice on wiring Conn pipe speakers to a Conn 550



Lajko, Hello again. This is OrgansR4Me in Florida.I had found a terrific set of JBL speakers and thought they would sound awesome connected to the pipe circuit on my Trinidad.

They worked for about 5 minutes and then I lost all volume on my main channel voices. Do you have any advice on troubleshooting what may have blown out? Turns out I didn't do my homework. The circuit was 8 Ohms and the speakers were 16!

I need to get the repair done ASAP as some one is returning a Yamaha FS-500 ( and also having us store a lovely Yamaha Clavinova long term ) and I need to pass along the Trinidad to a new home. I have a prospective new home for the Conn lined up with my friends daughter in N.C. and my friends will truck it there in their Yukon if I can complete the repair in the next few weeks.

Any guidance will be greatly appreciated. I have the service manual and a host of schematics in an additional supplement. My first suspicion is in an area on top the amp assembly that says it is the cards for the complex voicing circuit. The germanium transistors on those boards have a strange halo of a chalky powder around them that doesn't seem quite normal. (There are four / two for each board).

I'll be checking the service literature more next week, but for now I have to clean up my garage and put away the pieces I've been parting. I'm also lining up a home for my Wurly 4375 and having to pass on the AGO Wurly church organ I was planning to get in exchange for the Trinidad. But getting back the Yamaha is exciting and worth the extra effort. (comes at a time when I've been quite ill and didn't contemplate doing any organ repairs for the next few months but opportunity was knocking!)

Thanks for your time and ideas! Best regards, Paul D