In the interim I found the service bulletin #16. Is there a particular 47uf or 50uf brand cap that is recommended? What kind of cap was found in the original Hammonds in the 60's?
Looking at the schematic of the service bulletin, I would suspect you'd want some sort of non-polarized cap.
Also, I question Hammond's wisdom of using the 50 uF / 10 Ohm combination, as that makes a 318Hz high-pass filter. On the other hand, I haven't taken into account the impedance of the tone generator itself. Tone #37 is 262Hz, so it would actually attenuate the desired tone somewhat. If I were doing this mod (and I've considered it for tones 37 to 43 of my M-111), I'd use a 47uF non-polarized electrolytic (e.g. https://www.digikey.com/product-deta...008-ND/2597871) and 15 Ohm resistor, which will lower the cut-off frequency to 226Hz.
Looking at the schematic of the service bulletin, I would suspect you'd want some sort of non-polarized cap.
Also, I question Hammond's wisdom of using the 50 uF / 10 Ohm combination, as that makes a 318Hz high-pass filter. On the other hand, I haven't taken into account the impedance of the tone generator itself. Tone #37 is 262Hz, so it would actually attenuate the desired tone somewhat. If I were doing this mod (and I've considered it for tones 37 to 43 of my M-111), I'd use a 47uF non-polarized electrolytic (e.g. https://www.digikey.com/product-deta...008-ND/2597871) and 15 Ohm resistor, which will lower the cut-off frequency to 226Hz.
Thanks! And regarding the tonehweel caps, I will be using the method of matching to the coils for highest output. Which currently available caps would be best? There are some that say it won't make an audible difference in a tonewheel and others that disagree. I'm leaning towards polyester. Would the current poly line of Panasonics sold in mouser be ok?
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