Hammond 44 HP: broken mike?

Homepage Forums Melodica construction, repair and maintenance Hammond 44 HP: broken mike?

This topic contains 6 replies, has 2 voices, and was last updated by  Gianluca Barbaro 4 months, 3 weeks ago.

Viewing 7 posts - 1 through 7 (of 7 total)
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  • #10675

    Gianluca Barbaro
    Participant

    Hi all,
    I have recently bought a used 44 HP from Japan: the price was ok and the melodion in itself works well, but I get a “weird” output from the internal mike. It’s like there’s a strong resonance of sort in the medium/high range. Having a PRO44H too, I have compared the two and the output from the latter doesn’t have the same “noise”. Also, I have noticed that the HP model has a sort of plastic membrane in front of the capsule, while the 44H doesn’t (just a “latex” cover). I don’t know if the mike is damaged or maybe it’s a mechanical problem between this plastic diaphragm and the mike. Any insight?
    Also, has anyone an idea of where I could order a replacement mike set?

    Thanks,
    gl

    #10679

    Melodica-Me
    Participant

    Gianluca, try Westmusic, I purchased reed sets for both 44 and 44HP as well as gaskets and a lost volume knob. They may have the source for your parts.
    Hope this helps
    Melodica-Me

    westmusic_2@shop.rakuten.co.jp
    Att: Go Kawamoto
    Website
    http:/www.rakuten.co.jp/westmusic/

    • This reply was modified 4 months, 4 weeks ago by  Melodica-Me.
    #10684

    Gianluca Barbaro
    Participant

    Hi Melodica-Me, you’re right! I hadn’t thought about Mr Kawamoto! I’ll try…
    What’s your take on the different diaphragm between the two Hammond 44?
    gl

    #10687

    Melodica-Me
    Participant

    Hello Gianluca, I like them both and I have not had any issues in all these years other than replacing the reeds once for both and I only replaced the sectional reed plate that had a bad reed, and still maintaining the same tonal quality as the existing reed played not replaced I bought from Mr Kawamoto.
    Melodica-Me

    #10688

    Gianluca Barbaro
    Participant

    Here’s what I’m talking about. This is the diaphragm in front of the mike in a Hammond Pro44H:

    http://www.barbaro.it/cms/images/temp/Hammond_Pro44H_mike_diaphragm.jpg

    And here’s the different diaphragm in a Pro44HP:

    http://www.barbaro.it/cms/images/temp/Hammond_Pro44HP_mike_diaphragm.jpg

    I don’t know what to make of such a different design between the two models…

    In any case, it turns out the casing elements from the two models are interchangeable, so I tried and swapped the microphone parts between the two, and it worked:

    http://www.barbaro.it/cms/images/temp/Hammond_PRO44_hybrid.jpg

    It looks like, in my case, it’s definitely a mike capsule problem, because now it works well…

    cheers
    gl

    #10689

    Melodica-Me
    Participant

    I am wondering if this is due to a different type of reed thickness, or plating technique on the reeds. They state that they are both Phosphorous bronze plated but the HP are much brighter. If you are familiar with the Hohner Basso Melodica it has a diapram as well to try to provide constant pressure maybe the difference is in the elasticity of the bladder material? I will ask a few friends that are in with Suzuki and maybe they can tell us the reason.
    Melodica-Me

    #10690

    Gianluca Barbaro
    Participant

    Melodica-Me, I’m not sure it has to do with chamber pressure. It looks like the HP diaphragm extrudes towards the capsule: maybe it is supposed to mechanically transmit vibrations to the capsule? Or to exalt some vibration range? I’m just guessing…
    In any case, Mr Kawamoto proved himself invaluable once again: I was able to order a couple of mike capsules from them, although it will take 2/3 weeks to have them shipped.
    I’m thinking about adding a second capsule, in parallel to the existing one, at the other end (basses): once the parts arrive I’ll make some experimentation…
    gl

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