Recapping and Leakage

[geldo79]

Hi,

I am wondering what recapping of a tone generator will do to the leakage of the organ.
My M3 is a bit muddy and from time to time I think I should recap it. But on the other hand,
I really like to hear leakage in the tone. Will a recapped tone generator will produce leakage at all?

I have to say that my M3 does not have much leakage in the tone now. I think it's because the high frequencies are not coming through. But if I would recap the tone generator and the result would be a clear tone with lots of high frequencies but without leakage, I would not be happy as well.

Another question in this context would be: What parts of an AO29 amp could be the source of muddy sound. Doing replacements in the amp should be much easier than recapping the TG, but I don't really know which parts (caps) to replace or to check.

What do you think?

Greetings,
Christian

[Bobmann]

Hi,

I am wondering what recapping of a tone generator will do to the leakage of the organ.
My M3 is a bit muddy and from time to time I think I should recap it. But on the other hand,
I really like to hear leakage in the tone. Will a recapped tone generator will produce leakage at all?


I have to say that my M3 does not have much leakage in the tone now. I think it's because the high frequencies are not coming through. But if I would recap the tone generator and the result would be a clear tone with lots of high frequencies but without leakage, I would not be happy as well.

Another question in this context would be: What parts of an AO29 amp could be the source of muddy sound. Doing replacements in the amp should be much easier than recapping the TG, but I don't really know which parts (caps) to replace or to check.

What do you think?

Greetings,
Christian

In my experience, leakage noise is more pronounced after recapping the TG.
I install RC filters as prescribed by Hammond in their Technical Service Bullitins, and are already installed on the lated TG.

Bob

[muckelroy]

Hi again Geldo79,

Before I attempt to give an answer to this question, let me say this:
-- You have posted a large number of threads to the organ forum, regarding a large number of issues with your organ and Leslie. As far as I can tell, those threads have no definite fix. We don't know if you still have a problem unless you respond to a thread and say that problem is fixed.

If you have a reputable tech in your area, call that person and get their estimate for servicing your AO-29. I do recall seeing some extravagant work done to your Leslie 122 amp. While the work may appear aesthetically pleasing, I would say you don't need for a tech to re-invent the AO-29 or change the circuit in any way. You simply want the AO-29 to have any faulty components replaced, and not to change the circuit, nor even deviate too far from how the components are mounted.

Do not make a decision about recapping your tone generator until you have a properly functioning AO-29.

That said, if I am reading your past threads correctly, this organ is actually an M2 that has been converted to an M3, so yes, if true the organ almost certainly has paper and wax capacitors on its higher frequencies of the tone generator, and those tones are almost assuredly of lower gain than they could be.

Regarding "leakage", that word means a lot of things to a lot of people. When I hear someone refer to "tone leakage", I think that means "crosstalk", which is hearing other frequencies bleed through when you play a tone. All tonewheel Hammond organs will have this to some extent, and re-capping will help your higher frequencies to have a little less of it. However it will still be there. Every Hammond behaves differently and has a slightly different amount of crosstalk. The generator is not the only source of crosstalk. Dendrites in the manual contact bins, faulty ground connections, etc,... these could all contribute to it.

Keep in mind that re-capping alone may not be satisfactory. You will have some notes that are much louder than their neighbors, or quieter than their neighbors. That's what calibration is for, but I won't discuss that because there are plenty of threads on the forum about this which you can read if you want.

We are happy to offer advice, but it is hard to do so until you go back and close the loop on your previous threads, and tell us if those issues are, or are not resolved. Good luck!

Edit: Thanks Bobmann. RC filters will reduce crosstalk at the generator level. I didn't think to mention that, because the OP said he likes "leakage".

[geldo79]

Hi,

Yes I know....I had some threads in that context. Concerning the Leslie, I think it is working properly now after I set it back to stock configuration. But as I still miss some highs.....the remaining problem should be inside the organ I guess.....or inside the Leslie-kit. I have to say that the organ had more highs and leakage when I played it through a Leslie clone before I bought the 122, but the clones always sound brighter I think.

[geldo79]

But does anyone have an idea which parts of an AO29 to check/replace if its output is too dull?

[tpappano]

There are two small capacitors, C1 and C6 in the vibrato and non-vibrato preamp sections. They are high frequency roll-off caps for click filtering. Disconnecting these on my M3 brought up the highs noticeably. I had also replaced the TG filter caps which made a huge improvement.

[geldo79]

Ok. Thanks for your information. Did you also have to recalibrate your TG after recapping?

[tpappano]

I measured all the output levels and they varied quite a bit but stayed within about +/- 3 db. It sounds pretty good but I think recalibration might be worth the trouble if I can do it without disconnecting the wire harnesses 8)