A100 Tone Leakage and finding tonewheel wire

[sjoerd1234]

Hey guys,

I'm afraid I need you guys help again... Today I finished the refelt of the keycombs and key polishing of the upper manuel. Before I start on the lower manual I decided to play the organ first to feel the result and check if it still works.
The sound is awesome as ever and the keys feel really good, but I noticed that there is some tone leakage that wasn't there before, sigh... Man, fix one thing and cause another, very frustrating.
The leakage or hum is noticable when not playing, it is not very loud and the volume of it adjusts with the expression pedal. The drawbars or presets don't have any effect on the hum.
The hum sounds like someone is pressing his hole hand down on the keys, I recorded it, it sounds quite loud on the recording but it's pretty soft in comparison to playing: spraak_180403.mp3

I have no clue where to look for this does anyone know what it might be?
The organ was restored about two years back, it has all new capacitors, resistors, tubes etc. so that wouldn't be it

Also the first drawbar, on the most right octave, the D note doesn't work on both upper and lowe manuals. This would mean that there's a broken wire on the tonewheel.
Where would this wire be located? I can't find any loose wire on the front of the tonewheel, should it be here?:

(not my organ)

[Tim_at_Jonas]

The wires on the back of the TWG are the first ones to check. After that, the ones under the manual - I found one that was never soldered at the factory. If still no joy, you can test all off the tones by connecting a long clip lead to one of the preset terminal bars, then touching the other end to each terminal on the back of the generator in turn.

[sjoerd1234]

The wires on the back of the TWG are the first ones to check. After that, the ones under the manual - I found one that was never soldered at the factory. If still no joy, you can test all off the tones by connecting a long clip lead to one of the preset terminal bars, then touching the other end to each terminal on the back of the generator in turn.

Thanks for the tip, I’ll check it out

[Wes]

Check all your grounds. The TG body, manuals, and preset panels are grounded with the last three or five TG lugs on the right hand side. The manual ground screws to the bottom of the manuals. The TG tray ground is very important and grounded through screws to the TG body. These screws often come loose.

To find your missing tone, look at this interactive page: http://www.dairiki.org/hammond/wiring/

[sjoerd1234]

I checked again there are no loose wires on the tonewheel. Since the problem is on both manuals on the same key, the wire problem should not be on the manual itself right? Also the problem is on only the first drawbar of all drawbar sets on that single key on both manuals.

I checked the organ today for quite some time. The tone leakage is driving me mad, I can't find the source. I touched all wires, tubes etc to check for changes in the leakage but nothing. Things I did before the hum appeared:
- Removed top cover and drawbar assembly out of the way, kept them still attached
- Removed keycombs for refelt
- Removed all upper manual keys for polishing
- removed some parts attached in front of the keys to get to the keyscrews including a little board with some wires and resistores and preset rack (had to remove two presetstrips to get to screws behind)
- I did not remove any wires or other conections besides the ones from the strip on the preset rack which I put back after

Other threads suggest old resistors or electrolytic capacitors but I had those replaced everywhere two years back. I'd say even if it would be the resistors or capacitors the leakage would not just suddenly appear like that.

- - - Updated - - -

Check all your grounds. The TG body, manuals, and preset panels are grounded with the last three or five TG lugs on the right hand side. The manual ground screws to the bottom of the manuals. The TG tray ground is very important and grounded through screws to the TG body. These screws often come loose.

To find your missing tone, look at this interactive page: http://www.dairiki.org/hammond/wiring/

Thank you for the info! I did not see your post before my last post. I will check it out

[muckelroy]

Listening to the recording, it sounds like someone playing a very big, huge and gutsy C suspended chord.

Did you clean the bus bars? If so, you might need to repeat the process, making sure that the Cancel preset is engaged throughout, so as to ensure no preset key contacts are mistakingly stuck down. However even that problem wouldn't necessarily make it sound like playing keys being played. I suppose it is possible to make this problem occur if one or more key actuators were being pressed down while reinserting the bus bars. (i.e. if the top of the manuals were leaning up against something, or sitting upside down on a bench.)

I would also strongly suspect a ground problem, which on a Hammond is not as cut and dry as you might think. There are multiple ground wires, and all of them should be black in color. The A-100 wiring diagram is your friend. Look at each wire either labeled with the ground icon, or "BK". Trace it to see where it is going. Hammonds don't have a single ground point, but the jist of it is that all of the drawbars and manuals are grounded at the preset panel, and then the matching transformer. The matching transformer is grounded to the generator chassis (far right terminals.) The Matching Transformer also is grounded to the preamp chassis by means of metal braided shielded wires that run in to the matching transformer, and are connected via a small flathead screw and lug on the lid of the matching transformer (much like the grounds on the preamp connections are attached.)

Odd problems can happen when the drawbar assembly is not firmly bolted to the manuals, so be sure to tighten the hex head screws that hold the drawbars to the drawbar base of the manuals.

Finally (but this is NOT a conclusive list), tighten the flathead screws that hold the filter tray to the top of the tonewheel generator. Do not over-tighten or strip them, though. The tray is thin brass, and those threads can be stripped by more than being hand-tight.

[Wes]

I see you were into the preset panel. That's the first ground to check. :)

[sjoerd1234]

To find your missing tone, look at this interactive page: http://www.dairiki.org/hammond/wiring/

Thanks for the link! I found the wire, although it's a resistor wire on top of the tonewheel, attaching that will be very hard:-P see pic:

I moved it around and in the position it is on the photo the tone works, although I do not know why. It doesn't seem to touch anything
As for the grounds I checked the ones on the tonewheel, preset panel, matching transformer and under the manuals, the screws are tight and wires intact.
They seem to be connected correct

[sjoerd1234]

Listening to the recording, it sounds like someone playing a very big, huge and gutsy C suspended chord.

Did you clean the bus bars? If so, you might need to repeat the process, making sure that the Cancel preset is engaged throughout, so as to ensure no preset key contacts are mistakingly stuck down. However even that problem wouldn't necessarily make it sound like playing keys being played. I suppose it is possible to make this problem occur if one or more key actuators were being pressed down while reinserting the bus bars. (i.e. if the top of the manuals were leaning up against something, or sitting upside down on a bench.)

I did not clean the bus bars, Those are thos long metal strips right? I saw it on a video.

I would also strongly suspect a ground problem, which on a Hammond is not as cut and dry as you might think. There are multiple ground wires, and all of them should be black in color. The A-100 wiring diagram is your friend. Look at each wire either labeled with the ground icon, or "BK". Trace it to see where it is going. Hammonds don't have a single ground point, but the jist of it is that all of the drawbars and manuals are grounded at the preset panel, and then the matching transformer. The matching transformer is grounded to the generator chassis (far right terminals.) The Matching Transformer also is grounded to the preamp chassis by means of metal braided shielded wires that run in to the matching transformer, and are connected via a small flathead screw and lug on the lid of the matching transformer (much like the grounds on the preamp connections are attached.)

Thank you for the detailed ground explanation. i checked multiple ground wires, couldn't find anything so far.

Odd problems can happen when the drawbar assembly is not firmly bolted to the manuals, so be sure to tighten the hex head screws that hold the drawbars to the drawbar base of the manuals.

They are firmly bolted on.

Finally (but this is NOT a conclusive list), tighten the flathead screws that hold the filter tray to the top of the tonewheel generator. Do not over-tighten or strip them, though. The tray is thin brass, and those threads can be stripped by more than being hand-tight.

I don't really know what you mean with this, though I suspect this would not be it. The only thing I did was temporally unblot the preset manual to get to the keyscrews and lift the upper manual.
Really appreciatie your detailed post thanks

[sjoerd1234]

I see you were into the preset panel. That's the first ground to check. :)

Those are the ones on the lower right strip right? See pic:
(not my organ)

I removed strip 5 and 6 counting from top to bottom. To do that I had to remove all screwed wires.
First I did 5, only to find out that it needed to be 6 in order to get to the screws behind it.
I documented all removed wires and put everything back after

[muckelroy]

I don't really know what you mean with this, though I suspect this would not be it. The only thing I did was temporally unblot the preset manual to get to the keyscrews and lift the upper manual.
Really appreciatie your detailed post thanks

What I mean is, on the tonewheel generator is a large brass tray that houses all of the LC filters (coils, capacitors, and associated wiring.) This tray is covered by a large swatch of green felt, with holes cut out for the oil funnels. So you'd need to gently lift the felt up and check the flathead screws which mount the brass tray to the generator. A short fat flathead screwdriver is your friend for tightening these. There are several screws on the back edge of the tray, and several screws on the front edge of the tray. The ones on the front edge are most easily accessed by propping the manuals up and reaching under them.

[Wes]

Yep, those are the grounds. Make sure they are tight. Also check the manuals' grounds, since the wires run near there. If that doesn't pan, the TG filter tray screws are next.

[sjoerd1234]

Yep, those are the grounds. Make sure they are tight. Also check the manuals' grounds, since the wires run near there. If that doesn't pan, the TG filter tray screws are next.

Checked the grounds, everything is tight and connected. I noticed today when I slightly press down the preset keys for both drawbars sets of the bottom manual at the same time the tone leakage is 3 times louder. This does not happen when i do the same on the upper manual drawbar preset keys. Can this have a relation to the preset rack? I did remove 4 strips including the attached srews to get to the screws behind it. The leakage was not there in the slightest before I took the organ apart for a keycomb refelt and keypolish.
As mentioned by you guys I'll check the
Filter tray screws next

[muckelroy]

I assume you removed the top 4 strips of the preset panel? That's interesting, because ground is the bottom strips. I don't know how messing with the top strips in any way would have caused this problem.

Each manual has 9 twisted bundles coming from the first 9 preset keys. For those wires, it really does not matter where they are attached, as that is the choice of the user to determine their presets.

However, what matters is where the wires from the drawbar base go, as well as where the signal exits the preset panel to the matching transformer. Check every color of both sets of drawbars, that they are attached to the correct terminal of the preset panel. On the bottom strip of the preset panel, verify there is a black wire attaching both "halves" of the panel. Check that all of the wires on the far right of both of the upper and lower manual panels go to the matching transformer, noting the bottom one should be the black wire. Finally if you did anything to the matching transformer at all, check every connection inside it.

[sjoerd1234]

I assume you removed the top 4 strips of the preset panel? That's interesting, because ground is the bottom strips. I don't know how messing with the top strips in any way would have caused this problem.

Each manual has 9 twisted bundles coming from the first 9 preset keys. For those wires, it really does not matter where they are attached, as that is the choice of the user to determine their presets.

However, what matters is where the wires from the drawbar base go, as well as where the signal exits the preset panel to the matching transformer. Check every color of both sets of drawbars, that they are attached to the correct terminal of the preset panel. On the bottom strip of the preset panel, verify there is a black wire attaching both "halves" of the panel. Check that all of the wires on the far right of both of the upper and lower manual panels go to the matching transformer, noting the bottom one should be the black wire. Finally if you did anything to the matching transformer at all, check every connection inside it.

Thanks you for the explenation. I removed the 5th and 6th strips from the top see pic from previous post:

4 strips in total. Behind the 6th strips the screws are located. I first thought the 5th but I was wrong, that's why initially the two 5th strips were removed. The bottom strips are connected with wire and from the right three black wires are connected correctly, going to the matching transformer and 1 being ground goes to the ground on the TG.
The matching transformer has been altered, it has a Trek II FX loop installed. But that has been this way for more than 2 years now. I reconnected the wires from the FX loop on the mathing transformer already to test if that was the cause of the tone leakage. The mathing transformer has not been tempered with during the work I did. everything seems to be connected properly in the matching transformer, i checked the connections. Can this maybe also be a busted tube or something?
Damn when I fix this tone leakage I will finally have a fully restored A100 and leslie after almost 5 years, it's literally the last thing on the list.