Hf-85 volume pot

Discussion in 'Eico Place' started by Madman1, Feb 15, 2018.

  1. Madman1

    Madman1 New Member

    Messages:
    22
    Location:
    Winston Ga
    So I’m having a tech do some work on my hf-85 and of course the volume pot is a mess. So I’m looking for info on replacements. Seems the alps 500k dual will work since I’ve read some of you guys have used that. I also see I’ll probaby need the shaft extension and the adapter. I guess my biggest question now is how to make the double knob work out. Do you just glue them together and the larger rear is a dummy and the front knob actually controls the volume? If you can share what you’ve done and maybe a picture or two, I’d really appreciate it.
    Thanks guys!
    Mark
     

     

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  2. stoN_Cold

    stoN_Cold Super Member

    Messages:
    3,061
    Location:
    Belgrade, Serbia
    Yes 500K with loudness dpdt.
     
  3. audiocarp

    audiocarp New Member

    Messages:
    15
    Location:
    Jamaica, NY, USA
    There is no off-the-shelf solution that allows you to keep your knob original. Your tech. will have to cobble something together by either modifying the EICO knobs, using new-style knobs or modifying the shaft adapter to fit EICO knobs. The other issue are the taps for the Loudness switch. You can do without this function or contact Mark Oppat at Old Radio Parts and I'm sure he can construct an exact copy out of his stash of NOS parts. http://www.oldradioparts.net/
     
  4. Madman1

    Madman1 New Member

    Messages:
    22
    Location:
    Winston Ga
    Ok, I did talk to Mark and I will most likely go with that solution but, I was curious how much if any an improvement the alps would be over the carbon type pot. I think I found a alps dual with loudness but, it’s from China and I’ve read about counterfeit alps.
    Thanks,
    Mark
     
  5. vendo81

    vendo81 AK Subscriber Subscriber

    Messages:
    1,757
    Location:
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    I just put one in last week for a friend and I used a stepped ALPS. It has taps but I didn't use them as my friend wanted the loudness gone. I glued the two knobs together. I ended up cutting the inner and outer end off an extra pot I had and used a sleeve (epoxied) to attach the two.
    I didn't notice any difference between the original and new pot sound wise but he wanted a stepped ALPS pot.
     
  6. audiocarp

    audiocarp New Member

    Messages:
    15
    Location:
    Jamaica, NY, USA
    Is this from the Alps RK27 "Blue Velvet" line? Those are widely counterfeited, so, you really have to know your supplier to make sure it's legitimate. Parts Express has a few RK27 types, but not in 500K and nothing with taps. I just checked the alps.com website and they don't even make a 500K in the RK27 line! I assume anything ordered from China, Hong Kong, Taiwan, etc. with a name-brand has to be counterfeit. As to your other question, I'm sure it would be an improvement over the original, but, I haven't tried it yet.
     

     

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  7. stoN_Cold

    stoN_Cold Super Member

    Messages:
    3,061
    Location:
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  8. audiocarp

    audiocarp New Member

    Messages:
    15
    Location:
    Jamaica, NY, USA
    Vendo81, I had no idea Alps made a stepped attenuator. Where did you get it?

    Ston_cold, I think they're all fake, with the possible exception of the one from Germany. It's often very hard to tell if a part is genuine simply by looking at its exterior, because that is where counterfeiters put all their effort, right? Stick with well-known suppliers and you can't go wrong.
     
  9. stoN_Cold

    stoN_Cold Super Member

    Messages:
    3,061
    Location:
    Belgrade, Serbia
    I'm holding on.
     
  10. Madman1

    Madman1 New Member

    Messages:
    22
    Location:
    Winston Ga
    Thanks guys! Yea, my tech was not interested in doing a lot of fabrication to make the pot fit so, I have Mark putting one together. Also like what most of you said I was having a hard time finding them except from China...no thanks. Regardless the new one will be leaps ahead of the old one. Thanks again for all your advise.

    Mark
     
  11. vendo81

    vendo81 AK Subscriber Subscriber

    Messages:
    1,757
    Location:
    California
    I bought 2 of them several years back from a place in Germany. They do work quite well but the original I removed was working fine and sounded ok to me. I didn't try it out in my stereo system before and after so the comparison was on my work bench with test speakers.

    STAY AWAY from any Alps made in China, although I've read they are getting better.
     
    Last edited: Apr 18, 2018

     

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  12. audiocarp

    audiocarp New Member

    Messages:
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    Location:
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    Better-quality counterfeits?!
    On the Alps website, they have a worldwide inventory locator, and it shows only one supplier in the US (Mouser), one supplier in Europe (RS Components), 3 in Japan and none in the rest of the Pacific Rim. So, consider that as your legit supply chain. I also see that the RK271 series is now obsolete; so, grab up the remaining supply while you can! The recommended replacement is the RK1681xMG series, which are all motorized types.
    http://dilp.netcomponents.com/cgi-b...er1=RK271&partnumber2=&partnumber3=&pq=Search
     

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