New member that's just acquired a dead Hammond Aurora Classic

[JamesB]

I'm new to the world of organs. I have MIDI wave table and FM synth equipment like my Korg M50/88, Yamaha DX-21, etc, but no actual organs.

Earlier this week I was offered a Hammond Aurora Classic that apparently doesn't work. All I have to do is pick it up (hopefully this will happen on Saturday afternoon if the weather holds). I have no idea what the owner means by "doesn't work", but I figured that other than a bit of time and effort to go and get it (it's located about 70km away), I really have nothing to lose.

I have a 28 year employment history in the ground side of aviation electronics (installing and teaching stuff like enroute navigation and landing systems, communications, RADARs), and a few more years freelancing my technical skils, so digging my way around a piece of transistorised hardware doesn't phase me.

I'm guessing first place to start is fuses and then power supply, and after that I guess it's time to look at the electrolytic capicators. I suspect the real challenge will be finding circuits/service manuals.

James

[andyg]

After checking fuses, the next thing is probably to unplug, clean and reseat every internal connector. It's regarded as routine maintenance for this class of organ. Think mother/daughter board plug-ins and all ribbon cables. Then start looking at the PSU. E-caps may well be OK but worth a check of course.

You can request a service manual here on the forum - there's a dedicated section for that. Have a look through - the details may already be in that section. There's also a lively Facebook group - Vintage Organs Group - and there are Aurora Classic owners on there who will be more than happy to share their knowledge with you.

And on here, we also have a bunch of organ technicians who are always very helpful. If it's possible, we'll get the organ working. It's Hammonds biggest and best LSI spinet and has some very good sounds.

Just be aware that if you do get it working, you may well be saving up for the matching Leslie speaker cabinet that takes the sound up to the next level! :)

[KC9UDX]

The first thing I would do is look for one that already works. Free Aurora Classics that work are as common as dirt round here.

[JamesB]

The first thing I would do is look for one that already works. Free Aurora Classics that work are as common as dirt round here.

Probably so, but in rural Nova Scotia, where the nearest large city (Halifax) is a 3 hour drive away, it's a case of take what's offered and then consider the problems later.

[JamesB]

After checking fuses, the next thing is probably to unplug, clean and reseat every internal connector. It's regarded as routine maintenance for this class of organ. Think mother/daughter board plug-ins and all ribbon cables. Then start looking at the PSU. E-caps may well be OK but worth a check of course.

I'll probably introduce all the connectors to Stabilant 22. It's my treatment of choice for connectors. I'm progressively going through the connectors in the vintage Jaguar XJ-S I am restoring in an attempt to deal with their notorious reputation for connector intermittents.

You can request a service manual here on the forum - there's a dedicated section for that. Have a look through - the details may already be in that section. There's also a lively Facebook group - Vintage Organs Group - and there are Aurora Classic owners on there who will be more than happy to share their knowledge with you.

I'm already an active member of the "Vintage Synth Repair And Mods." group, so I'll look for the vintage organs group.

And on here, we also have a bunch of organ technicians who are always very helpful. If it's possible, we'll get the organ working. It's Hammonds biggest and best LSI spinet and has some very good sounds.

Just be aware that if you do get it working, you may well be saving up for the matching Leslie speaker cabinet that takes the sound up to the next level! :)

The current owner was going to break it up, dump the electronics, and feed the wood into his heating stove if it wasn't gone in a week. I couldn't let that happen.

[KC9UDX]

Probably so, but in rural Nova Scotia, where the nearest large city (Halifax) is a 3 hour drive away, it's a case of take what's offered and then consider the problems later.

Very good point. Kudos for taking the initiative to fix this thing. And very good on the Jag repair, too!

[JamesB]

It's -6°C outside, the sun is shining, and there's something like 10cm of snow still on the ground from the snow that fell on Thursday morning, but it's the nicest day we've had all week.

This morning's activity is getting the chicken coop that my wife bought 2 weeks ago, out of the trailer so I have room to pick up the Aurora this afternoon. Tomorrow, the weather will turn nasty again, so this afternoon is my best chance for a pick-up run.

[JamesB]

I got it home .... less of a problem getting it into my house than it was getting it out of the basement at the owner's place (although he tells me it was far easier to get it up the stairs than the piano he moved out of there last month).

The tag under the keyboard tells me it was Made in Canada. Model 232172 and Serial C 62895

It's not totally dead. The precussion section works.

There's a fair bit of 60Hz hum. The volume of the hum increases the longer it has been switched on, so that looks like an electro capacitor isn't happy. There's also a screech that comes out of the speakers after it's been on for about 30 seconds.

I'll be digging into it further as I get time.

[auronoxe]

Good luck! I own one myself, and could fix one or two little glitches with the help of this forum during the last years. The organ really has a very nice drawbar sound. I love the real inbuilt Leslie - better than the simulated thing on my Technics organ.

[JamesB]

Good luck! I own one myself, and could fix one or two little glitches with the help of this forum during the last years. The organ really has a very nice drawbar sound. I love the real inbuilt Leslie - better than the simulated thing on my Technics organ.

There's an empty box in the base section where I assume a mini-Leslie would be located.

[KC9UDX]

I think these Leslie speakers were optional. I wouldn't cry over the lack of it. The sound is better than most fakes, but nowhere near as good as a good external one. And the inertia is highly disappointing.

[kkeys]

Stock Aurora Classics have an internal Leslie. The revolving baffle and back speaker enclosure should be styrofoam. I would think the Leslie would be the same as used in the Colonnade (built in Canada) that I used to have. The Aurora classic would have an 11-pin external Leslie socket, Plug and play for models 715, 415, 720 and others.

The internal Leslie in the Concorde in the video is a Rotosonic, which is different than used in Hammond spinets.

[andyg]

I think I would cry if the internal leslie wasn't there! The sound is very sterile without it - one failing of the LSI series, which deliberately took away some of the perceived 'imperfections' of the original tonewheel instruments. If this one's had the leslie unit removed, I'd start looking around for anything else that's missing after having been parted out. :(

The internal leslie in almost all organs was the standard OEM unit with a foam rotor (very few used the Rotosonic drum shown in the video) and speed change is much snappier, a couple of seconds at most if set up correctly.

[auronoxe]

Fully agree. The Aurora Sound without „any“ Leslie (internal or external) is no big fun :-) Leslie combined with light vibrato plus Key Click is the closest thing to a tonewheel sound from a Hammond LSI one can get.

[JamesB]

I'll worry about the lack of a Leslie after I get the rest of the organ working.

For the moment, the repairs are not going to be a high priority ... the priority was rescuing it before it became scrap metal and kindling. It's in a spot in the living room where it's not in the way, so it can wait for me to complete a few other projects before I get serious with it, and I'll just tinker with it when I have a bit of free time.

The cats have already claimed the top as a nice spot to sit and preen and as there's no back on it, and it sits over half of a heating vent, yesterday I discovered two cats sleeping inside it ... the box where the mini-Leslie is supposed to go makes a great resonator for cat purrs. Stuck a camera over the top and took a photo.

Lots of dead bulbs. My usual LED replacement bulb suppliers in China tend to send parts by slow mail, so I'll figure out what bulbs are needed and get an order together quickly. It looks like the bulb in the expression pedal is dead, so that's a definite replacement I need to find. The pedal is also separate from the base. I'm assuming that it's just 2 screws or pivot posts that need to be replaced. One of the metal posts that mounts a pedal (the E) is broken (the original owner tells me that the pedal snapped off when it caught on a rug while he was moving it around before I got there) so I'll need to either repair it/fabricate a new one/get a replacement.

For interest, here's a shot of unloading it after I got it home. The weather was not nice, but the snow held off for the entire 88km drive home and until after I got it unloaded and into the house. It traveled in the trailer on its back strapped on a wooden pallet with a blanket covering the keyboard/switches. Getting it up the stairs and through all the doors in the house required it to be strapped upright onto a hand cart.