Eico hf-61 phono stage

Discussion in 'Eico Place' started by maciek, Jul 3, 2013.

  1. maciek

    maciek Active Member

    Messages:
    282
    I have this eico hf-60 that came with hf-61 preamp I played CDs through aux and sounded very good,yesterday I hooked up turntable but could not get any sound from it,it has few phono inputs like log riaa amer78 and euro78,any ideas what could be wrong?bad tube switch or else?thanks for sharing any experience on this thanks
     
  2. dcgillespie

    dcgillespie Fisher SA-100 Clone

    Messages:
    9,165
    Location:
    Ball Ground, GA
    My HF-61 had the very same problem, which was traced to the section of the can cap that serves the phono preamp being so bad as to not let any B+ pass to the phono stage. Once it was replaced, the phono stage now works great.

    Use your voltmeter to check that B+ is present at the preamp section. Or, simply check that the voltages at the preamp tube terminals are in line with those indicated on the schematic. If they are, and you at least get the usual noise/hum associated with the phono stage, but no signal, then check the selector switch contacts. If there is no rushing noise from the preamp, but B+ is present, then check the tube.

    I'm sure you'll find the issue somewhere in these tests. Good luck with it!

    Dave
     
  3. maciek

    maciek Active Member

    Messages:
    282
    Thanks Dave,there is indeed some hum anyway i turn phono position,thanks for some hints,another thing how would you compare sound quality of hf-61 and hf-85,i have two hf-60's one awaiting restoration,wondered what would be better to run both with hf-85 or with two separate hf-61's thanks for any advice or link to thread on it,thanks
     
    Last edited: Jul 3, 2013
  4. dcgillespie

    dcgillespie Fisher SA-100 Clone

    Messages:
    9,165
    Location:
    Ball Ground, GA
    Besides the mono/stereo element, the 61 and 85 are two distinctly different animals design wise -- which is to say that the 85 is not just two 61s on the same chassis, as so often was done in the early days of stereo. Both units invert the phase, and both use active tone control circuitry. But the 61 has a much more extensive Rumble and Scratch filter network that the signal goes through to a certain extent even when these are not selected. For me, that gives an edge to the 85, with a more direct and simple signal path. Such designs tend to sound more dynamic and alive IMO of course.

    I hope that helps!

    Dave
     
  5. maciek

    maciek Active Member

    Messages:
    282
    Re

    That means hf-61 might produce more coloration than hf-85,I used passive volume control for my HK cit ii and it sounds very analytical comparing to hf-60 with hf-61,maybe hf-85 falls somewhere in between ,thanks for your opinion Dave
     
  6. gkargreen

    gkargreen Active Member

    Messages:
    360
    Location:
    Fairfax, VA
    Hi, Dave, you indicated that you have a schematic with the voltages marked on it for the HF-61, is there somewhere I can get that schematic? The ones I have have no voltage marking on them. Thanks, Randy
     

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