Repair of a Gulbransen organ

[Jimelectr]

Hi, I'm brand new here, and I just came into possession of a Gulbransen organ today. People down the street were tossing it out, and I couldn't resist. There's no label on it, but when I opened the back, I could see the Gulbransen Amplifier Model APS-5 on the amplifier. 5 vacuum tubes in the power amplifier, and they appear to be 2X 12AU7A's, 2X 6L6 GC, and 1X 5U4 GB. My background is solid-state, being a professional electrical engineer for 30 years, but from hanging around guitar amp nuts (and from tubes' respective sizes) I know that the 12AU7A's are small-signal tubes, and the 6L6's are power tubes. Never heard of the 5U4 before. Unfortunately somebody got the pedals before me (d'oh!).

So, the red Power light and the green Chime Solo light, both on the right side, and the white Percussion light and the orange Reverberation light, both on the left side, all work properly. But the sound, to my ears, is the same no matter which stops (is that the correct term?) are pulled out. In this case, they are switches that are flipped down. I can hear relays switching when I flip most of them down. No sound coming out when the keys on the left side of the lower manual are pressed, and I can tell that some of the pitches of the keys are off. Some don't work at all. Anybody know which model Gulbransen I have in my garage now?

I'm not super familiar with organs, and I've never heard of the Tierce, Nazard, and some of the other labels on the switches. And what do the 16', 8', 5 1/3', 2 2/3', etc. mean? Lengths of pipe organ pipes? 8' versus 16' would suggest an octave above, and the fractional ones may be other intervals. I'm not a super music theory guy, but I do know a little bit. I play electric bass, keyboards, and guitar, so I can't help but have absorbed a bit. I suppose I could bring my portable keyboard with the speakers included out to the garage where the definitely non-portable organ is and check pitches a bit better.

Any help in getting this glorious old beast working again is appreciated. I have several oscilloscopes, digital and analog multimeters, power supplies, etc. in my garage lab, so as far as testing of the electronics goes, I'm set (just got to remember to remove my rings before poking around in there!). Oh, maybe the audio spectrum analyzer will come in handy, too.

Thanks.

Jim

[andyg]

Welcome to the forum, Jim.

It would help to know just what model you have. There should be a maker's plate on there somewhere, but a photo or two should let us ID it.

You're correct in your reasoning about the pitches. 8' is concert pitch, same as a piano, 16' an octave lower, 4' an octave higher. The fractionals will play a 5th above the key pressed, so a C will sound as a G.

There are several threads, possibly many threads, about repairing Gulbransens on the forum. A search should pay dividends and at the bottom of the thread you'll see a box called 'Similar Threads' and that does what it says on the tin!

Pity about the pedals, as it's unlikely that you'll be able to find replacements. As for what's wrong, that's for our electronics experts, not me!

[Organfella]

Unfortunately somebody got the pedals before me (d'oh!).

Hi Jim. Welcome to the Forum. Once you are able to post some pictures please do so then we can see what we are talking about.

I may have a set of pedals off a Model 1100 (The very first Gulbransen spinet). If it has a very heavy cabinet of solid wood and somewhat rounded edges we are on the right track! However, I need to check as I may have dumped it. Will look again tonight and let you know later. Here is a picture of my one before dismantling. The third white pedal has kinda lost a bit of the end but that could easily be repaired...:



Take Care.

Nico

[Jimelectr]

Thanks, Andy and Nico. No indication of model unfortunately, unless it's on the bottom! Not going to catch me lifting it, though! Here's a photo.

Pedals went all the way across, under the volume pedal.

Jim

[Organfella]

OK, That is not a spinet so the pedals I have will not work. Nice organ though but a lot newer that my poor old one. The typical wooden front panel is nice, I bet the back panel is also solid 3/8" wood... If you can find pedals and the rest works OK, you might have yourself a good one, but perhaps there is a good reason why it was tossed in the first place.

Good luck!

Nico

[Silken Path]

Jim, can you go introduce yourself and ask about the pedals and bench? The pedals may end up in a flower bed. (Women can be funny about what they'll put in a flower bed.)

[johnbeetem]

I'm not a Gully expert so I may be wrong, but it looks like a Model E "classic" version from what I've seen from Internet searches.

[andyg]

John is correct, that's a Model E in Traditional ('classic') style cabinet. You need those pedals! Short of finding another Model E, you won't find another set. You'll be able to play the organ without them, but not properly. And, yes, the bench would be handy. They might have been able to sell that to someone - console benches are sometimes the only part of an old organ that actually has a value.

Looking down at 'Similar Threads' I can see some about Model E's, so have a look through.

[Jimelectr]

Thanks, Nico. The back panel is indeed solid wood.

Say, is there a vacuum tube amp guru on the Forum?

Jim

[Jimelectr]

Yeah, it looks classic, alright! They don't make 'em like that anymore.

Jim

[Jimelectr]

Well, I didn't see the bench on the folks' driveway, just the pedals. I was going to grab those since I know the Roland or Moog ones I saw in a catalog a while back were $800-900. Seems outrageous to me for MIDI stuff.

Jim

[libraryguy]

I have a President that needs a good home. The case looks similar to your E. Mine has the pedal s with it.

I think it wouldn't all that hard to build a bench for that organ.

Are you in east Texas?