New member with diagnosing problem.

[Mike van]

Hello forum members. I have been a member for about a month. I have a Baldwin 45HP2. Serial number 11017-B3. I adopted this organ for free. When I got it home the A#'s were not working and there was a crackling sound. I have invested about 20 bucks. Replaced bad tube in tone generator. And sprayed contact cleaner on the main volume control pot for the manuals. Thanks for the past articles in the forum from the experts. Now I have noticed that when I have any 8ft. Stop on I get this uncrisp dirty sound with a slow reinterating beating sound. It only occurs on the first two octaves of the D and E notes on both manuals and the pedals. I have basic electronic experience and am handy. I am not sure what to do. It is worse after the organ warms up. I just want to be able to practice on this organ. But this makes It hard to play. The noise is no louder than the other notes being played. It's in pretty good shape otherwise, with one previous owner. They had the purchase sale from 1962 ......$1,500. A lot of money then !
I hope someone can help with this problem.

[jbird604]

There have been ongoing problems with "biasing" of the old tube-type tone generators in Baldwins. You may have a little round socket on the generator chassis labeled "bias" and I think it might be there for hooking up some kind of test equipment. But I seem to recall that there was a "quick fix" for bias problems that involved sticking a resistor of a certain size onto two of the socket holes.

Maybe someone with experience on that model will chime in. There are people who work on those, such as Lynn Spelts in Fayetteville, Arkansas (find him on facebook). It is a specialty, and having one of those generators completed renovated and properly biased costs hundreds of dollars. But Lynn might be able to sell you some service literature that would help you figure it out yourself.

[Mike van]

Thanks for your help and information, John. Do you think that this organ would make a good candidate for a vpo? Course hooking up the keys and pedals, etc. Might be a lot of work.
Mike

[jbird604]

That might be a good use for it, given that the generator system is probably failing and could cost a lot of money to fix. At least the console is very well made and sturdy, so you have a good platform to work with. Only you can decide if it looks like something you want to invest with time and money and keep in your house.

Baldwin keyboards of that day are sturdy too. The only trouble might be figuring out how to use the key switches in a MIDI system, as they are probably not simple on/off contacts, but rather some kind of gradual contact devices. You would have to determine for yourself whether or not it's worth the time and trouble of converting them. Might be better off to look for some later model keyboards that do have regular switches under the keys.

Or you could try to save it and keep it as it is. Start with some basic troubleshooting, since you have electronic experience. Start with the power supplies and make sure they are delivering the correct DC voltages with minimal AC ripple. They may need some new filter capacitors, and that could make quite a difference in the organ's overall sound. The generator system can't deliver good tones if it doesn't have stable voltages to work with.

You are facing the same dilemma that many of us face -- what to do with beautiful old organs that need a lot of work. Since I'm in the organ business, I see a LOT of these and have had a lot of them coming into the shop and never going out. Some of them have no redeeming qualities -- poorly made consoles, lousy keyboards, flimsy pedals, old electronics completely used up, obsolete parts, sounded crummy anyway when brand new. It's hard to justify saving something like that, but most of the time an old organ has at least SOME good qualities that make it hard to throw away. But the sheer number of these things that people are trying to get rid of is what creates my biggest issues. The dumpster has been my friend many times...

[Mike van]

I guess I have a soft spot for these old organs. I would prefer to get it working right. This organ is a year younger than me. I also don't have a huge budget. Most of my experience with electronics is with much newer components. Could you please tell me how to check the voltages in the power supply? I don't want to short out something and make things worse. I can certainly replace the caps. I did get a service manual with schematics. So I have invested more time than money, so far. Time is not a problem. Since I recently retired. Thanks for your time and expertise John !
Mike

[jbird604]

Since you have bought the schematics, you only need to open the generator assembly and find the voltage sources. It has been a great many years since I worked on one of these, so I can't tell you were to look. The service manuals are often very well written and illustrated, so maybe there are pics in there to point you the way. You can start with the transformer of course, and follow through to the rectifiers and finally to the filter caps and any voltage-dropping resistors along the way.

Remember that there are HIGH VOLTAGES inside a tube-driven organ! 400 to 500 volts in some spots, so don't take any chances! Check and then double-check every time you move something to make sure that you haven't brought any metal parts too close to a voltage rail or tube socket or other spot where there might be super high voltage. Don't touch anything in there with your bare hands or with a metal tool unless you know exactly what you are touching!

You'll need a good meter of some kind. Good digital auto-ranging volt meters these days can handle those high voltages, and if you don't have one you should get one. After verifying that the various rectifiers are passing DC, check across each filter capacitor to be sure you don't have more than a small amount of AC anywhere. In solid state equipment, AC ripple of more than a few thousandths of a volt is unusual, but I'm not sure that applies in tube circuits. But if you should read several volts of AC across some filter cap, that might indicate a problem. You could probably Google that and find out for sure how much ripple is acceptable in a tube circuit.

There is even a large thick book you can buy on re-calibrating a Baldwin tube-type generator. You might have to invest in that book if you don't get it going by simply renovating the power supplies. But it's all rather basic technology. Best of luck!

[Mike van]

Thanks for the very useful advice. I will see what I can find out with my meter. I will keep you posted. I'll have more questions.
Mike