How Loud (Mechanically) Should My Tonewheel Generator Be?

[stefanv]

I have only ever heard one Hammond organ running up close, mine. Sometimes I wonder if my tone generator makes too much mechanical noise. I tried to get a good recording of what it sounds like, but I haven't been able to make one that doesn't sound far worse than the real thing.

Does anyone have a good way of describing how loud it should be? There's sort of a constant background wwww-wwww-wwww-wwww and a slight chicka-chicka-chicka at the same time. I have to play quite loud before I don't find it annoying. That wouldn't be a problem if I actually were any good. :-)

FWIW, it works well, and takes about 15 seconds to come to a stop after turning it off. I've had the organ about 10 years now, and oiled it once per year with Hammond oil. It hasn't gotten any better or worse in that time.

[Roger Memphis]

I have to play quite loud before I don't find it annoying.

That's too loud, Stefan. You should have to listen carefully to hear it. Check to see if the generator is floating properly on its springs. It could be making contact with the cabinet somewhere, and that would resonate/amplify the sound. Check any linkages, stiff bulky wire harnesses, etc., to make sure they are not transmitting the sound to the cabinet. At the risk of over-reaching, I assume that you have ruled out that the sound is coming from the speaker(s). Is there possibly a cover missing? Please let us know what you find.
Roger Memphis

PS: Re: your comment, "I have only ever heard one Hammond organ running up close, mine." ...Get out there and make friends with some other Hammond enthusiasts in your area! :)

[enor]

15 seconds isn't a very good roll out time for a 50Hz M-100. Anything below 18 seconds means I give the instrument a naphtha flush and a thorough re oiling (my goal is 20-22 seconds and I usually get there) - your generator might be a bit dry still.

[Sweet Pete]

Oh! It was running,it scared the *rap out of me!!!......type quiet.
Nice when you can't hear the Leslie or Tone Cabinets either.

Quite sure Stefan V has a 60Hz model,so 20 seconds or more is possible with a naptha flood followed up with 4 ounces of oil over a month.
Once that old detergent and residue is out of there the thing should be really quiet!

[muckelroy]

Unlock the generator T nuts, to ensure no cabinet resonance is occurring. (Nothing to do with the "clicking" noises you describe, but thought I'd mention it as no one else had.)

[KC9UDX]

Start motor stuck on?

[stefanv]

Thanks everyone for your replies. I'm convinced that my tone generator is far louder than it should be, and will start looking for potential problems (I'd like to avoid removing the generator from the organ if possible). The really obvious stuff, like generator bolted down or start motor stuck on I know not to be the case (the latter because the generator gets a lot quieter when the start motor is turned off). It's also not coming from the speakers, because the sound continues while the generator is spinning down after I turn the organ off.

[enor]

Flush it and oil it!

[stefanv]

Thanks enor. I did some googling, and found that a naptha flush was less onerous than it sounds. I thought I'd have to remove the TG and dip the whole thing. I'll wait until the weather's a bit warmer so I can open some windows while doing this (and I'll also check for other obvious sources of noise in the mean time).

BTW, in case it matters, the vibrato scanner was completely stuck when I bought the organ back in '08. At that time, I completely rebuilt the scanner, and it's been working fine ever since. But I wonder if there's anything worn on the scanner clutch that could be contributing to the noise?

[Jyvoipabo]

Hello,

You can also expect that the sun of August will warm your organ and melt the excess fat. Wait for summer. Expose your organ and wait.

The scientific method to find the origin of noise in industrial machinery is to use a spectrum analyzer.
With it you can know all about the boring frequencies (and about the ambient noise).
And may be locate the origin.

But this approch is tricky.

JP

[stefanv]

The scientific method to find the origin of noise in industrial machinery is to use a spectrum analyzer.

Good idea. The recordings I made weren't good enough to be able to show what it sounded like, but I was able to grab a spectrum out of it. I've annotated the peaks. I wonder if any of those correspond to any particular shaft rotational speeds:

[MihevicB3]

. . . BTW, in case it matters, the vibrato scanner was completely stuck when I bought the organ back in '08. At that time, I completely rebuilt the scanner, and it's been working fine ever since. But I wonder if there's anything worn on the scanner clutch that could be contributing to the noise?

I’m not sure if the M-111 scanner is the same “classic” that is in the B3, C3, M3, etc. If it is, I would, remove the motor/scanner from the TG. On my B3, I can remove the motor mounting nuts and get access to it without removing any wiring. I would then remove the three screws that attach the scanner to the run motor. Be careful with the end cap and that rotating pin that is the scanner output. Also, be, careful to pull out the cotton oiling wicks without breaking them. I would then mount the run motor back on the TG without the scanner and start the TG up. This will isolate where your noise is coming from.

This might seem like a lot of work, but, it’s not bad if you take your time and watch where you put those small screws, nuts and lock washers.

John M.

P.S. This is also a good time to direct oil the motor and scanner bearings. All my cotton wicks are broken and I direct oil the bearings this way every couple of years. It also keeps oil from getting all over the scanner insulators which seems to happen when the cotton wicks "dribble" oil all over everything.

[Sweet Pete]

Chasing down vacuum leaks on auto systems led me to my stethoscope.
Sure as my heart is beating,you will locate the noise with a decent one.Mine is a good quality medical stethoscope.
Have chased down bent ticking incorrectly installed pickup pins,improperly seated balancing springs,improperly seated stators.
It's a quick almost fool proof method.Even repaired a scanner bearing without drilling.A light adjustment quieted the issue.Once it was lubed all was good.

[stefanv]

Lots more great ideas here! I have a stethescope (a veterinary grade one), so will give that a try too.

[enor]

Don't overthink this.

With only 15 seconds roll out time and a freshly rebuilt scanner, we already know that you simply have excess friction in your tone generator.